Prasanna

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 22 Chemical Coordination and Regulation Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 22 Question Answer Chemical Coordination and Regulation

Chemical Coordination and Regulation Class 11 Questions and Answers CHSE Odisha

Multiple Choices Questions

Question 1.
Banting and Best (1921) established that:
(a) Deficiency of thyroxine causes hypothyroidism
(b) Oversecretion of cortisol causes Cushing’s syndrome
(c) Deficiency of insulin causes hyperglycemia
(d) Oversecretion of growth hormone causes gigantism
Answer:
(c) Deficiency of insulin causes hyperglycemia

Question 2.
Which one of the facts about hormones is correct?
(a) Hormones are proteins
(b) Hormones are released into the blood
(c) Hormones have no specific targets
(d) Hormones are secreted by exocrine glands
Answer:
(b) Hormones are released into the blood

Question 3.
Which one of the following is not true?
(a) Steroid hormones act through second messengers
(b) Glycoprotein hormones include TSH, FSH and LH
(c) Epinephrine and norepinephrine are catecholamines
(d) Sertoli cells secrete androgen binding protein
Answer:
(a) Steroid hormones act through second messengers

Question 4.
Which of the following statements about the hypothalamic releasing and release-inhibiting hormones is true?
(a) They are secreted into capillaries in the median eminence
(b) They are transported by portal veins to the anterior pituitary
(c) They stimulate the secretion of specific hormones from the anterior pituitary
(d) All of the above are true
Answer:
(d) All of the above are true

Question 5.
The hormone primarily responsible for increasing the basal metabolic rate and promoting the maturation of the brain is:
(a) Cortisol
(b) ACTH
(c) TSH
(d) Thyroxine
Answer:
(d) Thyroxine

Question 6.
Which of the following statements about adrenal cortex is true?
(a) It is not innervated by nerve fibers
(b) It secretes some androgens
(c) The zona glomerulosa secretes aldosterone
(d) The zona fasciculata is stimulated by ACTH
(e) All of these are true
Answer:
(b) It secretes some androgens

Question 7.
Which of the following statements about insulin is true?
(a) It is secreted by alpha cells of islet of Langerhans
(b) It is secreted in response to a rise in blood glucose concentration
(c) It stimulates the synthesis of glycogen and fat
(d) Both (a) and (b) are true
(e) Both (b) and (c) are true
Answer:
(e) Both (b) and (c) are true

Question 8.
Steroid hormones are secreted by
(a) Only Adrenal cortex
(b) Only Gonads
(c) Only Thyroid
(d) Both (a) and (b)
(e) Both (b) and (c)
Answer:
(d) Both (a) and (b)

Question 9.
The secretion of which of the following hormones will be augmented in a person with endemic goiter.
(a) TSH
(b) Thyroxine
(c) Triiodothyronine
(d) All of these
Answer:
(a) TSH

Question 10.
Which of these hormones uses cAMP as a second messenger?
(a) Testosterone
(b) Cortisol
(c) Insulin
(d) Epinephrine
Answer:
(c) Insulin

Question 11.
Which of these hormones may have a role in circadian rhythm.
(a) Estradiol
(b) Insulin
(b) ACTH
(d) Melatonin
Answer:
(d) Melatonin

Question 12.
Which one of the following about ACTH is true ?
(a) It stimulates the entire adrenal cortex
(b) It stimulates zona glomerulosa only
(c) It stimulates both zona fasciculata and reticularis
(d) It stimulates zona reticularis only
Answer:
(c) It stimulates both zona fasciculata and reticularis

Question 13.
Which one of the following statements is false?
(a) Corpus luteum secretes progesterone
(b) Progesterone maintains pregnancy
(c) FSH stimulates interstitial cells of Leydig
(d) Sertoli cells are somatic cells, secreting androgen binding protein
Answer:
(c) FSH stimulates interstitial cells of Leydig

Question 14.
Granulosa cells secrete:
(a) Cortisol
(b) Estradiol
(c) Testosterone
(d) Progesterone
Answer:
(b) Estradiol

Question 15.
Which of the following is correct?
(a) T₄ changes into T₃ in the target cell
(b) T₃ changes into T₄ in the target cell
(c) T₃ and T₄ act as such on target cell
(d) T₃ changes into T₄ and vice-versa in the target cells
Answer:
(a) T₄ changes into T₃ in the target cell

Very Short Answer Type Questions

Express the following statements in one word.

Question 1.
The study of glands secreting hormones and their functions.
Answer:
Endocrinology

Question 2.
The part of the brain that secretes the releasing and release-inhibiting hormones.
Answer:
Hypothalamus

Question 3.
The stalk that attaches the pituitary with the hypothalamus.
Answer:
Infundibulum

Question 4.
The part of the hypothalamus, where the primary capillary plexus is present.
Answer:
Median eminence

Question 5.
The division of the anterior pituitary that secretes the tropic hormones.
Answer:
Adenohypophysis

Question 6.
The hormone, which acts on the renal tubule and promotes the absorption of water.
Answer:
Vasopressin

Question 7.
The hormone that regulates the height before adolescence.
Answer:
Growth hormone

Question 8.
The hormone that promotes early stages of gametogenesis.
Answer:
Testosterone

Question 9.
The hormone that promotes the development of breasts.
Answer:
Estradiol

Question 10.
The hormone that acts on the smooth muscle of uterus and facilitates the birth of a baby.
Answer:
Oxytocin

Question 11.
The blood vessel that carries the releasing, release-inhibiting hormones from the hypothalamus to the anterior pituitary.
Answer:
Hypothalamoportal vessel

Question 12.
The iodinated glycoprotein present in the colloid of the thyroid.
Answer:
Thyroglobulin

Question 13.
Hypothyroidism in children with severe mental retardation.
Answer:
Cretinism

Question 14.
Hyperthyroidism, which is caused by auto-immune attack
Answer:
Graves disease

Question 15.
The hormone that stimulates the interstitial cells of the gonads.
Answer:
Luteinizing hormone

Question 16.
A synonym for adrenal gland.
Answer:
Triple F gland

Question 17.
The cortical steroid hormone that regulates mineral metabolism.
Answer:
Aldosterone

Question 18.
The pathological condition in which inadequate glucocorticoids and mineralocorticoid fail to negatively feedback the secretion of ACTH from the anterior pituitary.
Answer:
Cushing’s syndrome

Question 19.
The hormone that fluctuates in its concentration, when one flies different time zones.
Answer:
Melatonin

Question 20.
The formation of glucose from non-carbohydrates.
Answer:
Gluconeogenesis

Question 21.
Breakdown of glycogen into glucose.
Answer:
Glycogenolysis

Question 22.
The interstitial cells that secrete androgens.
Answer:
Leydigs cell

Question 23.
The graafian follicle turns into a progesterone secreting endocrine structure following ovulation.
Answer:
Corpus luteum

Question 24.
The phenotypic characters, which identify the sex of the individual.
Answer:
Secondary sexual characters

Question 25.
A collective name for adrenal medullary hormones.
Answer:
Catecholamines

Correct the sentences without changing the works underlined.

Question 1.
Thyroid stimulating hormone is an amine hormone.
Answer:
The hormone secreted by thyroid is amine hormone.

Question 2.
Posterior pituitary (neurohypophysis) originates from neural ectoderm.
Answer:
Anterior pituitary (adenohypophysis) originates from neural ectoderm.

Question 3.
Pars tuberalis secretes all the tropic hormones of the anterior pituitary.
Answer:
Pars distalis secretes all the tropic hormones of the anterior pituitary.

Question 4.
Pituitary is attached to the hypothalumus.
Answer:
Pituitary is attached to the hypothalumus.

Question 5.
Growth hormone induces hyperglycemia.
Answer:
Calcitonin and epineprine induces hyperglycemia.

Question 6.
Growth hormone excess in ah adult human causes gigantism.
Answer:
Growth hormone excess in an adult human causes acromegaly.

Question 7.
Prolactin induces milk ejection.
Answer:
Prolactin induces milk formation.

Question 8.
Adrenocorticotropic hormone acts on adrenal gland.
Answer:
Adrenocorticotropic hormone acts on adrenal cortex.

Question 9.
Deficiency of antidiuretic hormone causes diabetes mellitus.
Answer:
Deficiency of antidiuretic hormone causes diabetes insipidus.

Question 10.
Releasing inhibiting hormones are secreted from the posterior pituitary.
Answer:
Releasing inhibiting hormones are secreted from the anterior pituitary.

Question 11.
Calcitonin is secreted from the parathyroid gland.
Answer:
Calcitonin is secreted from the thyroid gland.

Question 12.
Alpha cells of islet of Langerhans secrete somatostatin.
Answer:
Delta cells of islet of Langerhans secrete somatostatin.

Question 13.
Adrenocorticotropic hormone acts on zona glomerulosa and promotes the secretion of aldosterone.
Answer:
Adrenocorticotropic hormone acts on zona fasciculata and zona reticularis of the adrenal cortex to secrete cortisol.

Question 14.
Cortisol and epinephrine are hyperglycemic by promoting gluconeogenesis and glycogenolysis, respectively.
Answer:
Cortisol and epinephrine are hyperglycemic by promoting gluconeogenesis and hepatic glycogenolysis, respectively.

Question 15.
Cells of the adrenal cortex are called chromaffin cells.
Answer:
Cell of the adrenal medulla are called chromaffin cells.

Question 16.
Day light induces the pineal gland to secrete less melatonin.
Answer:
Day light stimulus decreases the sympathetic stimulation of Pineal gland.

Question 17.
Sertoli cells secrete androgens.
Answer:
Interstitial cells secrete androgens.

Question 18.
Granulosa cells of the ovary secrete estrogens.
Answer:
Granulosa cells of the ovary secrete estrogens and inhibin.

Question 19.
Steroid hormones use the second messenger mechanism in their action on target cells.
Answer:
Protein hormones use the second messenger mechanism in their action on target cells.

Question 20.
Dwarfism is a consequence of prolactin deficiency before adolescence.
Answer:
Dwarfism is a consequence of growth hormone deficiency before adolescence.

Question 21.
Deficiency of dietary iodine causes thyrotoxicosis.
Answer:
Deficiency of dietary iodine causes endemic goiter.

Fill in the blanks

Question 1.
The active substance from the small intestine that stimulated the release of pancreatic juice was discovered by ……………. and ……………. in 1902.
Answer:
William M Bayliss, Earnest H starling

Question 2.
The word hormone was used by ……………. in 1905 for the active substance, secretin.
Answer:
Starling

Question 3.
Glycoprotein hormones include ……………. FSH and LH.
Answer:
TSH

Question 4.
Epinephrine and norepinephrine together constitute a group of hormones, known as ……………… .
Answer:
Catecholamines

Question 5.
All steroid hormones are derived from the parent compound, ……………. .
Answer:
Cholesterol

Question 6.
The role of 3,5 cAMP as a second messenger in the mechanism of hormone action was suggested by ……………. .
Answer:
Sutherland

Question 7.
Some hormones act through cell membrane receptors that stimulate adenylate cyclase activity and formation of ……………. .
Answer:
cAMP

Question 8.
The pituitary gland is attached to the floor of a part of fore brain, known as ……………. .
Answer:
hypothalamus

Question 9.
The pituitary is constituted by adenohypophysis and ……………. .
Answer:
neurohypophysis

Question 10.
The anterior pituitary is regulated by ……………. a part of the diencephalon.
Answer:
Hypothalamus

Question 11.
Adrenal medulla is constituted by cells that stain with chromates and hence are known as ……………. cells.
Answer:
Chromaffin cells

Question 12.
Posterior pituitary secretes two hormones, namely ……………. and ……………. .
Answer:
oxytocin, vasopressin

Question 13.
The group of hormones that binds to nuclear receptors is derived from the parent compound, ……………. .
Answer:
cholesterol

Question 14.
Tropic hormones are secreted from ……………. of the anterior pituitary.
Answer:
Pars distalis

Question 15.
The hormone, ……………. promotes breast development in female.
Answer:
estrogen

Question 16.
Oversecretion of growth hormone in adults causes an abnormality, known as ……………. .
Answer:
Acromegaly

Question 17.
ACTH is formed from a larger polypeptide, known as ……………. .
Answer:
Proopiomelanocortin

Question 18.
FSH stimulates the Sertoli cells to synthesise androgen binding protein and two hormones, namely inhibin and ……………. .
Answer:
activins

Question 19.
During development, the regression of mullerian ducts occur in the male by a hormone called antimullerian hormone. This hormone is secreted from the ……………. cells of the testis.
Answer:
Sertoli cells

Question 20.
The hormone ……………. is responsible for the ejection of milk from the breast of the lactating mother.
Answer:
Oxytocin

Question 21.
The growth promoting effects of growth hormone are mediated by ……………. polypeptides synthesised by the liver cells under its influence.
Answer:
IFG-I like

Question 22.
Delta cells of the pancreas synthesise ……………. which acts as growth hormone inhibiting hormone.
Answer:
Somatostatin

Question 23.
Parafollicular cells of the thyroid gland secrete a hormone, known as ……………. .
Answer:
Calcitonin

Question 24.
The iodinated glycoprotein present in the thyroid follicle is known as ……………. .
Answer:
Thyroglobulin

Question 25.
Interstitial cells of the testis are the targets of action of ……………. .
Answer:
FSH

Question 26.
Blood calcium level is monitored by hormones ……………. and ……………. .
Answer:
Calcitonin, parathyroid hormone

Question 27.
The releasing and inhibiting hormones of the hypothalamus act on the anterior pituitary via a blood vessel, known as ……………. .
Answer:
Hypophyseal portal vein

Question 28.
Alpha cells of .the pancreatic islets secrete a hormone, known as ……………. .
Answer:
glucagon

Question 29.
Over secretion of thyroid hormones causes an abnormality of the thyroid, known as ……………. .
Answer:
Hyper thyroidism

Question 30.
The enzyme ……………. catalyses the conversion of ATP into 3,5 cyclic AMP.
Answer:
adenylate cyclase

Question 31.
Estrogens are secreted by ……………. cells of the ovary.
Answer:
granulosa cells

Question 32.
Corpus luteum is an important source of a steroid hormone, ……………. .
Answer:
progesterone

Question 33.
Day night cycle is regulated by a hormone ……………. secreted from ……………. .
Answer:
melatonin, pineal gland

Question 34.
……………. has been designated as emergency hormone.
Answer:
Adrenaline

Question 35.
Inadequate secretion of both glucocorticoids and mineral ocorticoids from the adrenal cortex causes-a disease, known as ……………. .
Answer:
Addison’s disease

Question 36.
During stress, the immune system is suppressed by the hormone ……………. .
Answer:
Glucocorticoids

Question 37.
There is an insulin insufficiency in ……………. diabetes mellitus.
Answer:
Type I

Question 38.
Severe retardation of the nervous system in children due to a lack of thyroid hormones has been identified as ……………. .
Answer:
Cretinism

Question 39.
Excess release of ……………. can lead to water retention and consequently high blood pressure.
Answer:
ADH

Short Answer Type Questions

Question 1.
What is the relationship between hypothalamus and anterior pituitary?
Answer:
Hypothalamus and pituitary are related through blood supply. Hypothalamus regulates the synthesis and secretion of pituitary hormones.

Question 2.
Pituitary is not a master gland. Is it correct?
Answer:
No, it is not correct.
It is the smallest endocrine gland, but serves very important role in the human endocrine system. It directly or indirectly controls almost all other endocrine glands of the body. It is also known as master gland.

Question 3.
How are insulin and glucagon related?
Answer:
Insulin and glucagon are secreted by the gland pancreas. Insulin is hypoglycemic while glucagon is antagonistic to insulin and thus is hyper glycemic.

Question 4.
Name the hormone secreted by the delta cells of the pancreatic islet. What is its function?
Answer:
The hormone secreted by the delta cells of pancreas is somatostatin. Function of somatostatin is to inhibit the secretion of insulin and glucagon.

Question 5.
Pancreas is a mixocrine gland. Explain
Answer:
It is a composite gland that acts as both exocrine and endocrine gland. Such glands are also called heterocrine gland.
Origin: It originates from the endoderm of the embryonic germ layers.
Location: It lies below the stomach, in the loop of duodenum.

Question 6.
Why are catecholamines termed as emergency hormones?
Answer:
Both hormones belong to the category of compounds known as catecholamines and are secreted in response to any kind of stress, danger and during emergency situations like increased respiratory rate, heartbeat, etc.
The CNS at the time of stress or danger stimulates the adrenal medulla to release both these hormones. These are also known as emergency hormones or hormones of fight or flight.

Question 7.
How does cortisol handle stress?
Answer:
Cortisol
These are the hormones, which regulate the metabolism of carbohydrates, proteins and fats. Cortisol is the main glucocorticoid found in our body.
1. Cortisol is involved in the maintenance of cardiovascular system and in proper functioning of kidney.
2. Cortisol produces anti-inflammatory reactions and also during stress conditions functions by suppression of immune response.

Question 8.
Explain diabetes insipidus.
Answer:
Diabetes insipidus is a condition caused by the deficiency of hormones vasopressin. In this disease, there is a loss of water by frequent urination of dilute urine.

Question 9.
What is the main cause of type 1 diabetes mellitus?
Answer:
Type 1. diabetes is known as juvenile onset diabetes and it appears in people below the age of 20. It is caused, when beta cells are progressively destroyed by autoimmune attack by killer T lymphocyte. The consequence is that there is insulin deficiency.

Long Answer Type Question

Question 1.
Give an account of the structure of human pituitary gland and describe the functions of hormones secreted from it.
Answer:
Pituitary Gland (Hypophysis):
It is the smallest endocrine gland, but serves very important role in the human endocrine system. It directly or indirectly controls almost all other endocrine glands of the body. It is also known as master gland.

Origin: It originates from the ectoderm of the embryonic germ layers.

Location and Structure:
It is reddish grey in colour and is roughly oval in shape. It is about a size of a pea seed. The pituitary gland is located in a small bony cavity of the brain called sella tursica.

Anatomy:
The pituitary gland has three major lobes, i.e., anterior, intermediate and posterior lobe.
It is anatomically divided into two major portions
(i) Adenohypophysis It is the glandular anterior portion of the pituitary gland. It further consists of two parts, i.e., pars distalis and pars intermedia. These two parts represent the anterior and intermediate lobes of pituitary.
(a) Pars Distalis It also called anterior pituitary. It produces different hormones.
These hormones are given below with their functions

• Growth Hormone (GH), stimulates the somatotroph cells of anterior lobe of pituitary gland to release its growth hormone or somatotrophin. It stimulates body growth, protein, fat and carbohydrate metabolism. It also promotes skeletal growth by acting on epiphysical cartilages of long bones of children and adolescents.

• Prolactin (PRL) The prolactin releasing hormone stimulates lactotroph cells of the anterior lobe of pituitary gland to secrete its prolactin. PRL regulates the growth of mammary glands and formation of milk in them.

• Thyroid Stimulating
Hormone (TSH) Thyroid releasing hormone stimulates thyrotroph cells of the anterior lobe of pituitary to secrete its thyroid Stimulating Hormone, i.e., TSH or thyrotrophin. This TSH stimulates the synthesis and secretion of thyroid hormones from the thyroid gland.

• Adrenocorticotrophic Hormone
(ACTH) This is secreted when Adrenocorticotrophin Releasing Hormone (ACRH) stimulates the corticotroph cells of anterior lobe of pituitary. This stimulates the synthesis and secretion of steroid hormones called glucocorticoids from the adrenal cortex.

• Gonadotrophin Hormone It is the gonadotroph cells of anterior lobe of the pituitary gland, which secrete, luteinising Hormone (LH) and Follicle Stimulating hormone (FSH). Both of these hormones stimulate the gonadal activity hence, called gonadotrophin.

• luteinising Hormone (LH) In males, it stimulates the synthesis and secretion of hormones called androgens from testis. ‘While, in females, it induces ovulation of fully mature follicles (Graafian follicles) and also helps in maintaining the corpus luteum formed from the remnants of the Graafian follicles after ovulation.

• Follicle Stimulating Hormone (FSH) In males, the FSH and androgens together regulate spermatogenesis. In females, this hormone stimulates the growth and development of ovarian follicles.

(b) Pars Intermedia or Intermediate Lobe This portion of adenohypophysis secretes only one hormone,

• Melanocyte Stimulating Hormone
(MSH) The melanocyte releasing hormone stimulates the intermediate lobe of pituitary gland to secrete its Melanocyte Stimulating Hormone. MSH acts on melanocytes (melanin containing cells) and regulates the pigmentation of the skin.

(ii) Neurohypophysis It is a collection of axonaf projections from the hypothalamus, which terminate behind the anterior pituitary gland. It is pars nervosa of the neurohypophysis that forms the posterior lobe of pituitary gland.

The posterior pituitary stores and releases two hormones given below
(a) Oxytocin It is a short peptide of nine amino acids, also known as pitocin. It acts on the smooth muscles of our body and stimulates a vigorous contraction of uterus at the time of child birth. It also plays role in ejection of milk from the mammary glands in females.

(b) Vasopressin It is a small peptide hormone, also known as Antidiuretic Hormone (ADH) or pitressin. This hormone acts mainly at the kidney, stimulating the reabsorption of water and electrolysis by the distal tubules.
Thereby reducing the loss of water through urine (diuresis).

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 21 Neural Control and Coordination Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 21 Question Answer Neural Control and Coordination

Neural Control and Coordination Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
The myelin sheath around a nerve fibres in the peripheral nervous system is form by
(a) Oligodendrocytes
(b) Microglial cells
(c) Schwann cells
(d) Astrocytes
Answer:
(c) Schwann cells

Question 2.
The somatic sensory neuron conducts nerve impulse
(a) From a somatic receptor to the central nervous system.
(b) From central nervous system to the skeletal muscle.
(c) From the central nervous system to the smooth muscle and or glands.
(d) From a visceral receptor to the central nervous system.
Answer:
(a) From a somatic receptor to the central nervous system.

Question 3.
The cerebrospinal fluid is present
(a) In the subdural space only
(b) In the subarachnoid space only
(d) Both (b) and (c)
(e) Both (a) and (b)
Answer:
(e) Both (a) and (b)

Question 4.
The brain stem consists of
(a) Diencephalon, midbrain and pons
(b) Diencephalon, midbrain and medulla oblongata
(c) Midbrain, cerebellum and medulla oblongata
(d) Midbrain, pons and medulla oblongata
Answer:
(d) Midbrain, pons and medulla oblongata

Question 5.
Emotional states are regulated by
(a) Corpora quadrigemina
(b) Limbic system
(c) Basal nuclei
(d) Corpus callosum
Answer:
(b) Limbic system

Question 6.
Hypothalamus is a part of
(a) Telencephalon
(b) Metencephalon
(c) Diencephalon
(d) Mesencephalon
Answer:
(c) Diencephalon

Question 7.
Memory is regulated by
(a) Hypothalamus
(b) Hippocampus only
(c) Amygdala only
(d) Both (b) and (c)
Answer:
(d) Both (b) and (c)

Question 8.
The superior colliculi of corpora quadrigemina are involved in
(a) Auditory reflexes
(b) Visual reflexes
(c) Beleasing pituitary hormones
(d) Relaying of cutaneous information
Answer:
(b) Visual reflexes

Question 9.
In most people, the right side of the hemisphere controls the movements of
(a) the right side of the body primarily
(b) the left side of the body primarily
(c) both the right and left sides of the body equally
(d) head and neck only
Answer:
(b) the left side of the body primarily

Question 10.
In control of emotion and motivation, the limbic system works together with:
(a) pons
(b) thalamus
(c) hypothalamus
(d) cerebellum
Answer:
(c) hypothalamus

Question 11.
Lateral geniculate nuclei relay
(a) Auditory information
(b) Olfactory information
(c) Visual information
(d) Gustatory information
Answer:
(c) Visual information

Question 12.
Temperature regulation of the body is done by
(a) thalamus
(b) cerebellum
(c) hypothalamus
(d) medulla oblongata
Answer:
(c) hypothalamus

Question 13.
Respiratory and cardiovascular function are controlled by
(a) medulla oblongata
(b) cerebellum
(c) diencephalon
(d) telencephalon
Answer:
(a) medulla oblongata

Question 14.
Autonomic nervous system consists of nerves with:
(a) One neuron with one synapse
(b) Two neuron with two synapse
(c) One neuron with two synapse
(d) Two neuron with one synapse
Answer:
(d) Two neuron with one synapse

Question 15.
Parasympathetic ganglia are located
(a) in a chain parallel to the spinal cord
(b) in the dorsal roots of the spinal nerves
(c) next to or within the organs innervated
(d) in the brain
Answer:
(c) next to or within the organs innervated

Question 16.
The neurotransmitter of preganglionic sympathetic fibres is
(a) Norepinephrine
(b) Epinephrine
(c) Acetylcholine
(d) Dopamine
Answer:
(c) Acetylcholine

Question 17.
Depolarisation is characterised by
(a) Influx of sodium ions
(b) Efflux of potassium ions
(c) Influx of potassium ions
(d) Efflux of sodium ions
Answer:
(a) Influx of sodium ions

Question 18.
Gustation is related to
(a) sense of smell
(b) sense of taste
(c) sense of vision
(d) sense of hearing
Answer:
(b) sense of taste

Question 19.
Balance and equilibrium of the body is maintained by
(a) Semicircular canals only
(b) Saccule only
(c) Utricle only
(d) All of the above
Answer:
(d) All of the above

Question 20.
The retina consists of
(a) unipolar neurons
(b) bipolar neurons
(c) multipolsr neurons
(d) pseudounipolar neurons
Answer:
(b) bipolar neurons

Express the following in one word

Question 1.
The singular long process of a multipolar neuron.
Answer:
Axon

Question 2.
The functional junction between two neurons.
Answer:
Synapses

Question 3.
The nervous system constituted by cranial and spinal nerves.
Answer:
Peripheral nervous system

Question 4.
The cell that forms myelin sheaths around nerve fibres of the peripheral nervous system.
Answer:
Schwann cell

Question 5.
The neuron possessing one each of an axon and a dendron.
Answer:
Bipolar

Question 6.
The nerve fiber that carries neural motor nerves information from the central nervous system to the receptors.
Answer:
Efferent/motor nerves

Question 7.
A collective name for the connective tissue coverings of the brain and spinal cord.
Answer:
Meninges

Question 8.
The fluid that is present in the subarachnoid space, ventricles and central canal.
Answer:
Cerebrospinal fluid

Question 9.
Metencephalon and myelencephalon together constitute a part of the brain.
Answer:
Hindbrain

Question 10.
Midbrain, pons and medulla oblogata together constitute a part of the brain.
Answer:
Mid and hindbrain.

Question 11.
The fiber tract connecting the two cerebral hemispheres.
Answer:
Corpus callosum.

Question 12.
Corpus striatum is a perdominant part of the subcortical nuclei. Name the nuclei.
Answer:
Caudate and lentiform nuclei

Question 13.
The system and hypothalamus that regulate the emotional states of a person. Name the system.
Answer:
Limbic system

Question 14.
The vascular tissue that secretes the cerebrospinal fluid.
Answer:
Anterior choroid plexus and posterior choroid plexus.

Question 15.
The thalamic nuclei that relay visual information to the occipital lobe.
Answer:
Lateral geniculate nucleus

Question 16.
The inferior colliculi are the relay centres of a neural information. Name the neural information.
Answer:
auditory

Question 17.
The regulatory centres of the respiratory system and cardiovascular system lie in a part of the brain. Name it
Answer:
Medulla oblongata

Question 18.
Coordination of movements is executed by a part of the brain. Name it.
Answer:
Cerebellum

Question 19.
The communication between the third and fourth ventricles of the brain.
Answer:
Cerebral aqueduct

Question 20.
A fine connective tissue filament attached to th conus medullaris of the spinal cord.
Answer:
Filum terminale

Question 21.
The chemical substance that is secreted into th synaptic cleft by the presynaptic neuron.
Answer:
Acetylcholine (Neurotransmitters)

Question 22.
The Unconscious motor response to a sensory stimulus.
Answer:
Reflex arc.

Question 23.
The influx of sodium ions changes the polarity of distribution of electrical charges across the membrane of a nerve fiber. Name the process.
Answer:
Depolarisation

Question 24.
The conduction of nerve impulse along a myelinated nerve fiber.
Answer:
Saltatory conductions

Question 25.
Equilibrium or orientation with respect to gravity is controlled by an apparatus.
Answer:
Eustachian tube

Question 26.
The part of the membranous labyrinth connected with hearing.
Answer:
Organ of corti.

Question 27.
The tubular connection between the middle eai and pharynx.
Answer:
Eustachian tube

Question 28.
The part of the retinal that doesn’t contain any photoreceptor cell.
Answer:
Blind spot

Question 29.
The part of the retina, where an image is forme with highest resolution.
Answer:
fovea

Question 30.
Phtoreceptor cells of the retina that perceive colour.
Answer:
Cones

Question 31.
The fluid present in the membranous labyrinth.
Answer:
Perilymph

Question 32.
The fluid present in the bony labyrinth.
Answer:
Endolymph

Correct the sentences, if incorrect, without changing the words underlined

Question 1.
Somatic motor neurons conduct nerve impulse from the sensory receptors to the central nervous system.
Answer:
True

Question 2.
The central nervous system is constituted by the cranial and spinal nerves.
Answer:
The peripheral nervous system is constituted by the cranial and spinal nerves.

Question 3.
The autonomic motor neurons with their control centres constitute the somatic division of the peripheral nervous system.
Answer:
The autonomic motor neurons with their control centres constitute the autonomic nervous system.

Question 4.
The functional junction between a neuron and an effector cell is known as a synapse.
Answer:
True

Question 5.
In human, all synapses electrical.
Answer:
In human, all synapses are chemical.

Question 6.
The sequence of the menings from outer to inner is piameter, arachnoid mater and duramater.
Answer:
The sequence of the menings from outer to inner is duramater, arachnoid and piamater.

Question 7.
Cerebrospinal fluid is secreted by the meninges.
Answer:
Cerebrospinal fluid is secreted by anterior and posterior choroid plexus.

Question 8.
The functional junction between the two cerebral himispheres is known as corpus striatum.
Answer:
The functional junction between the two cerebral himispheres is known as corpus callosum.

Question 9.
Pineal gland arises from a part of the diencephalon, known as hypothalamus.
Answer:
Pineal gland arises from a part of the diencephalon, known as epithalaums.

Question 10.
The mass of cell bodies and axons running through the brain stem is known as corpus callosum.
Answer:
The mass of cell bodies and axons running through the brain stem is known as reticular formation.

Question 11.
Superior colliculi relay auditory information to the occipital lobe of the cerebrum.
Answer:
Superior colliculi relay visual information to the midbrain.

Question 12.
Medulla oblongata coordinates movement and equilibrium.
Answer:
Cerebellum coordinates movement and equilibrium.

Question 13.
Foramen of monro connects the third ventricle with the fourth ventricle.
Answer:
Cerebral aqueduct connects the third ventricle with the fourth ventricle.

Question 14.
In the spinal cord, the outer part is made by white matter, while the inner by gray matter.
Answer:
True

Question 15.
The gray matter consists of medullated nerve fibers.
Answer:
The gray matter consists of neural cell bodies and unmyelinated axons.

Question 16.
The somatic nervous system is constituted by nerves with two types of neurons and a synapse in a ganglion.
Answer:
Autonomic nervous system is constituted by nerves with two types of neurons and a synapse in a ganglion.

Question 17.
Acetylcholine is secreted as the neurotransmitter between pre and postganglionic fibers in both the sympathetic and parasympathetic divisions.
Answer:
True

Question 18.
In somatic motor reflex, the motor transmission is executed by one each of preganglionic and postaganglionic nerous with a synapse in a sympathetic ganglion.
Answer:
In somatic motor reflex, a somatic neuron conducts the impulse along a single axon from the spinal cord to the neuromuscular junction of a skeletal muscle.

Question 19.
Efflux of sodium ions and influx of potassium ions during nerve impulse conduction have been characterised as repolarisation.
Answer:
True

Question 20.
The correct order of the ear ossicles from outer to inner is incus, malleus and stapes.
Answer:
The correct order of the ear ossicles from outer to inner is malleus, incus and stapes.

Question 21.
Stapes is in contact with a round window.
Answer:
Stapes is in contact with a oval window.

Fill in the blanks

Question 1.
The central nervous system is constituted by …………… and …………….. .
Answer:
brain and spinal cord

Question 2.
The structural and function unit of the nervous system is known as ………………… .
Answer:
neuron

Question 3.
The basophilic granular material present in the neuron cytoplsam is known as ………………… .
Answer:
Nissel body

Question 4.
The axons of some neurons are encapsulated by an insulating lipid material, known as ………………… .
Answer:
myelin sheath

Question 5.
The myelin sheaths around the nerve fibers in the central nervous system is formed by ………………… cells.
Answer:
schwann

Question 6.
The efferent motor neurons that conduct impulse from the central nervous system to the visceral effectors are known as ………………… .
Answer:
visceral effector neuron

Question 7.
The functional junction between two neurons is known as ………………… .
Answer:
synapse

Question 8.
The junction between a neuron and effector is known as ………………… .
Answer:
myoneural junction

Question 9.
The impulse transmission across a synapse is carried out by a chemical substance, known as a ………………… .
Answer:
acetylcholine

Question 10.
The middle mening of the brain is known as ………………… .
Answer:
arachnoid

Question 11.
The brain is covered by a delicate connective tissue layer called ………………… .
Answer:
piameter

Question 12.
The dense fibrous connective tissue layer that forms a lining of the cranium is known as ………………… .
Answer:
durameter

Question 13.
The subarachnoid space is filled with a fluid called ………………… .
Answer:
cerebrospinal fluid

Question 14.
The cerebrospinal fluid is secreted by ………………… .
Answer:
choroid plexus

Question 15.
The brain stem is constituted by midbrain, ………………… and medulla oblongata.
Answer:
pons

Question 16.
Two cerebral hemispheres are connected by a fibrous tract, known as ………………… .
Answer:
corpus callosum

Question 17.
The cerebrum surface is marked by the presence of elevations and depressions, known as …………….. and …………….. respectively.
Answer:
gyri and sulci

Question 18.
The mass of cell bodies and axons that run through the brain stem constitutes ………………… .
Answer:
reticular formation

Question 19.
Corpora striata are integral parts of the predominant subcortical nuclei called ………………… nuclei or ganglia.
Answer:
caudate

Question 20.
Lateral geniculate nucleus relays ……………… information to …………….. lobe of the cerebrum.
Answer:
visual and optic

Question 21.
Medial geniculate nucleus relay ………………. information to ……………… lobe of the cerebrum.
Answer:
auditory and temporal

Question 22.
Superior colliculi and inferior colliculi are concerned with …………….. and ……………. functions, respectively.
Answer:
vision and hearing

Question 23.
The degeneration in the caudate nucleus causes a dominant genetic disorder, known as ………………. .
Answer:
Huntington’s diseases

Question 24.
The respiratory centres are situated in …………….. and …………….. of the brain.
Answer:
medulla oblongate and pons

Question 25.
Coordination in speech and movement are controlled by ………………. of the brain.
Answer:
cerebellum

Question 26.
Two lateral ventricles communication with each other and with the third ventricle through ………………. .
Answer:
foramen of monro

Question 27.
The ventricular communication between the third and fourth ventricles is known as ……………… .
Answer:
cerebral aqueduct

Question 28.
There are ……………. pairs of cranial and …………….. pairs of spinal nerves in human.
Answer:
10,31

Question 29.
The bunch of spinal nerves at the posterior end to the spinal cord, resembling a horse tail is known as ………………… .
Answer:
cauda equina

Question 30.
An autonomic nerve consists of ……………. number of neurons and …………….. number of synapses.
Answer:
two and one

Question 31.
The nerve fibers of the afferent (sensory) division convey information from the receptors to the central nervous system. Such fibers are classed as ……………..neurons in respect of the number of processes.
Answer:
pseudounipolar

Question 32.
Two neurons of an autonomic nerve fiber are termed as ……………. and ……………. .
Answer:
preganglionic nerve fibre, postganglionic nerve

Question 33.
The autonomic nervous system consists of two divisions, namely …………….. and ……………. .
Answer:
sympathetic and para sympathetic

Question 34.
The conduction of a nerve impulse along a myelinated nerve fiber is known as ……………… conduction.
Answer:
saltatory

Question 35.
The vestibular apparatus is constituted by the utricle, the saccule and ……………… .
Answer:
semicircular canals

Question 36.
Changes in linear acceleration, i.e. in velocity are regulated by ………….. and ………….. While changes in angular velocity are regulated by ……………. .
Answer:
utricle and saccule; crista ampullaris

Question 37.
The spirally coiled structure attached to the membranous labyrinth, which serves as the organ of hearing is known as ………………… .
Answer:
cochlea

Question 38.
The sensory part of the cochlea is known as ………………… .
Answer:
organ of corti

Question 39.
The innermost layer of the eye ball that contains the sensory cells is known as ………………… .
Answer:
retina

Question 40.
The visual sensory cells are of two types, namely …………… and …………. .
Answer:
rods and cones

Short Answer Type Questions

Question 1.
What is the function of myelin sheath?
Answer:
The myelin sheath is a protective covering that surrounds fibres called axons. The main function of myelin is to protect and insulate these axons and enhance the transmission of electrical impulses.

Question 2.
Why are gray matter and white matter named so?
Answer:
The type of fat in myelin makes it look white, so myelin-dense white matter takes on a white colour as well. In contrast grey matter is mostly neuron cell bodies which provide it grey colour.

Question 3.
Is there any difference between an efferent neuron and motor neuron?
Answer:
There is no difference between efferent and motor neuron, as they both carry nerve impulses from cental nervous system to the effector organs.

Question 4.
What is the role of limbic system?
Answer:
Limbic system include amygadala, hippocampus, thalamus, hypothalamus, basal ganglia and cingulate gyrus.
The limbic system supports a variety of functions including emotion, behaviour, motivation, long-term memory and olfaction.

Question 5.
Which parts of the brain regulate memory?
Answer:
Forebrain regulates memory. It is divided into two regions telencephalon constituted by two cerebral hemispheres (cerebrum) and diencephalon.

Question 6.
What is a chemical synapse?
Answer:
In a chemical synapse, the plasma membranes of pre and post synaptic neurons are separated by a fluid-filled space called synaptic cleft. The terminal part of pre synaptic neuron has endings called terminal boutons. These endings store a chemical substance known as neurotransmitter in synaptic vesicle. These neurotransmitters bring about depolarisation.

Question 7.
Cerebrospinal fluid is being secreted continuously by the choroid plexus. How is this volume kept constant?
Answer:
The volume of cerebrospinal fluid is kept constant, as after its production, it is absorbed and drained into the venous blood by arachnoid villi.

Question 8.
What do you understand by cerebral lateralisation?
Answer:
Cerebral lateralised refer to the fact that the two halves of the human brain are not exactly alike. Each hemisphere has functional specialisation. For example left hemisphere is specialised for language and speech abilities.

Question 9.
How is the day night cycle regulated by melatonin?
Answer:
Melatonin is involved in regulation of day-night cycles. The duration of melatonin secretion each day is directly proportional to the length of night. It is because the melatonin synthesising enzyme is low during daylight and peaks during dark phase.

Question 10.
What is a spinal nerve? Where does it originate from?
Answer:
The spinal nerve tracts are divisible into two, ascending (conducting sensory impulses towards brain) and descending (conducting motor impulses from brain).

Question 11.
Describe a pseudounipolar neuron.
Answer:
Pseudo Unipolar neurons These neurons have cell body with one axon only. These are found usually in the embryonic stage.

Question 12.
What are preganglionic nerve fibers? These are characteristic feature of which section of the nervous system?
Answer:
The fibres extending from CNS to the ganglion are know as preganglionic nerve fibres, whereas those extending from ganglion to the effector organ are called postganglionic fibers. These are characteristic features of autonomic nervous system.

Question 13.
What is sympathetic trunk? Describe about what it is made up of.
Answer:
Sympathetic trunk refers to a paired bundle of nerve fibres that run from the base of the skull to coccyx. The trunk represents 3 ganglia in the cervical part (superior, middle, inferior), 11 ganglia in the thoracic part, 4 lumbar and 4 sacral ganglia.

Question 14.
What is a reflex arc?
Answer:
The entire process of response to a peripheral nervous stimulation, that occurs involuntarily, i.e., without conscious effort or thought, requires the involvement of a part of the central nervous system is called a reflex action. .
The nervous pathway taken by nerve impulses in* a reflex action is called reflex arc.

Question 15.
What is an action potential? How does it help in the conduction of nerve impulse?
Answer:
When a stimulus of adequate strength (threshold stimulus) is applied to a polarised membrane, the permeability of the membrane to Na⁺ ions is greatly increased at the point of stimulation (site A).
(i) This leads to a rapid influx of Na⁺ followed by the reversal of the polarity at that site, i.e., the outer surface of the membrane becomes negatively charged and the inner side becomes positively charged. The polarity of the membrane at the site A is thus, reversed and neuron at that point is said to be depolarised.
(ii) The electrical potential difference across the plasma membrane at the site A is called the action potential, (another name of nerve impulse).

Question 16.
What is synaptic transmission?
Answer:
A brief description of the mechanism of synaptic transmission is given below
(i) When an impulse (action potential) arrives at a presynaptic knob, calcium ions from the synaptic cleft enter the cytoplasm of the presynaptic knob.
(ii) The calcium ions cause the movement of the syfiaptic vesicles to the surface of the knob.
The synaptic vesicles are fused with the presynaptic plasma membrane and get ruptured (exocytosis) to discharge their contents (neurotransmitter) into the synaptic cleft.
(iii) The neurotransmitter of the synaptic cleft binds with specific protein receptor molecules, present on the postsynaptic membrane.
(iv) This binding action changes the membrane potential of the postsynaptic membrane, opening channels in the neurolemma and sodium ions to enter the cell. This causes the depolarisation and generation of action potential in the postsynaptic membrane. Thus, the ‘ impulse is transferred to the next neuron.
(v) The new potential developed may be either excitatory or inhibitory.

Question 17.
Are there different regions in the tongue for different tastes? Yes or No. Justify.
Answer:
No,
Tongue is the organ for the sense of taste or gustation. It possess various taste buds located on it. These taste buds are called chemoreceptors or gustatoreceptors. There are three types of papillae present on the tongue.
1. Filiform papillae
2. Fungiform papillae
3. Circumvallate papillae or vallate papillae
In humans, there are approx 10,000 taste buds present on the tongue with each about 60-80 flm in diameter consisting of gustatory cells and supporting cells.

Question 18.
What is vestibular apparatus? How does it help maintain balance and equilibrium with respect to gravity?
Answer:
(i) The inner ear also contains a complex system called vestibular apparatus (located above the cochlea). It is composed of three semicircular canals and the otolith organ consisting of the saccule and utricle.
(ii) Each semicircular canal lies in a different plane at right angles to each other. The membranous canals are suspended in the perilymph of the bony canals. The base of canals is swollen and is called ampulla, which contains a projecting ridge called crista ampullaris, which contains sensory hair cells.
(iii) The saccule and utricle contain a projecting ridge called macula. The crista and macula are the specific receptors of the vestibular apparatus responsible for the maintenance of balance of the body and posture.

Question 19.
What is the role of fovea centralis in the image formation by the eye.
Answer:
The fovea centralis is responsible for sharp central vision, which is necessary in humans for activities where visual – detail is required like reading and driving.

Differentiate between

Question 1.
Axon and Dendron
Answer:
Difference between Dendron and Axons are as follows

Dendron	Axon
These are short fibres which branch repeatedly and project out of the cell body and also contain Nissel’s granules.	The axon is a long branched fibre, which terminates as a bulb-like structure called synaptic knob. It possesses synaptic vesicles containing chemicals called neurotransmitters.
These fibres transmit impulses towards the cell body.	The axons transmit nerve impulses away from the cell body to a synapse.
Its branches terminate into bulb-like synaptic knobs.	Their branches do not have synaptic knobs.

Question 2.
Schwann cell and Oligodendrocyte
Answer:
Schwawnn cells and Oligodendrocytes

Schwawnn cells	Oligodendrocytes
Perform a similar function in the Peripheral Nervous System.	Main function is to insulate the axons, almost exclusively in the central nervous system in the higher vertebrates.
Can wrap around only one axon.	The multiple layers of warpping of oligodenrocytes around the axons forms the mylein sheath.
There are two types myelinating and non-myelinating	The ’feet’ of a single oligodendrocyte can extend its processes to 50 axons, wrapping approximately 1 μm of myelin sheath around each axon.

Question 3.
Somatic nervous system and Visceral nervous system
Answer:
Somatic nervous system and Visceral nervous system

Somatic nervous system	Visceral nervous system
Somatic neurons are responsible for interactions with the outside world and voluntary movements. This includes touch, feeling pain, ticklish, etc. They are a part of peripheral nervous system.	Visceral neuron are part of the autonomic nervous system. They control involuntary movements of internal organs. An example of this is your heart that beats involuntarily.

Question 4.
Bipolar and Multipolar neurons
Answer:
Bipolar and Multipolar neurons

Bipolar Neurons	Multipolar Neurons
1. Bipolar neurons have two processes separated by the cell body.	1. Multipolar neurons have more than two process; there is a single axon and multiple dendrites.
2. Carry impulses from skin receptors to spinal cord.	2. It carry impulses from CNS to skeletal muscles.

Question 5.
Afferent neurons and Efferent neurons
Answer:

Afferent neurons	Efferent neurons
Afferent neurons are responsible for receiving and transmitting messages to the central nervous system from all parts of the body.	Efferent neurons are responsible for receiving and transmitting the message from the central nervous system to all parts of the body.
Afferent neurons make up sensory nerves.	Efferent neurons make up motor nerves.
Afferent neurons have a single long dendrite and a short axon.	Efferent neurons have a single long axon and several dendrites.
Afferent neurons are located just outside the central nervous system.	Efferent neurons are located inside the central nervous system.

Question 6.
Chemical synapse and Electrical synapse
Answer:

Chemical Synapse	Electrical Synapse
In chemical synapse, signal chemical molecules are neurotransmitters.	In electrical synapse, signal transmission happens in the form of electrical signals without the use of molecules.
Signals are modified during the transmission.	Signals are not modified during the transmission.
Neurotransmitters are released by exocytosis and diffused in the synaptic cleft and then are bound to receptors.	Electric signals pass via gap junctions.
Space between the pre and post synaptic ends is larger.	Space between the pre and post synaptic ends is very small.
Signal transmission happens only into one direction.	Signal transmission can happen in both directions.
Signal transmission requires energy. So its an active process.	Signal transmission happens without utilizing energy. So, its a passive process.
Single transmission happens at a moderate speed.	Signal transmission is extremely fast.

Question 7.
Corpus callosum and Corpus striatum.
Answer:

Corpus callosum	Corpus striatum
It is an arched mass of white matter in the depths of the longitudinal fissure, made up of transverse fibres connecting the cerebral hemispheres.	It is a subcortical mass of grey matter and white matter in front of and lateral to the thalamus “in each cerebral” hemisphere.

Question 8.
Medullated and Non-medullated nerve fibers.
Answer:

Medullated Nerve	Non-medullated Nerve
The axon is surrounded by a layer of fatty proteinaceous materials called myelin sheath.	Myelin sheaths are absent.
The myelin sheath provides white colour to the nerve fibre.	It appears grey in colour due to absence of myelin sheath.
Presence of nodes of Ranvier.	Nodes of Ranvier are absent.
The conduction of nerve impulse is faster	The conduction of nerve impulse is slower.
They are found in brain and spinal chord.	These are found in sympathetic and para-sympathetic nerves.

Question 9.
Sympathetic system and Parasympathetic system.
Answer:

Sympathetic system	Parasympathetic system
It consists of axons of neurons arising from the thoracic and lumber region of the spinal cord. Hence, this system is referred to as thoraco-lumber outflow.	It consists of axons of neurons arising from the cranial and sacral region of the spinal cord. Hence, this system is also referred to as cranio-sacral outflow.
It consists of short preganglionic and long postganglionic nerve fibres.	It consists of long preganglionic and short postganglionic nerve fibres
Its preganglionic fibres emerge with spinal nerves only.	Its preganglionic fibres emerge with cranial as well as spinal nerves.
It is very near to the spinal cord.	It is present nearer to the visceral organs.
It prepares the body to meet the emergency condition.	It relaxes the activities of body by restoring normal activities after stress.
Postganglionic fibres are numerous and are mostly adrenergic.	Postganglionic fibres are fewer and are cholinergic.

Question 10.
Somatic motor reflex and Autonomic motor reflex.
Answer:

Autonomic reflex	Somatic reflex
An autonomic reflex is one that involves the response of an organ, such as the peristaltic contraction of the smooth muscle of the intestine, that is not controlled consciously.	Somatic reflexes involves a response that involves a skeletal muscle contraction in response to a stimuli. Sensory nerves send signals through an afferent pathway to the central nervous system for processing.
The autonomic reflex is associated with one branch of the peripheral nervous system that regulates the sympathetic and parasympathetic nervous system.	A somatic reflex is a part of the other branch of the peripheral nervous system that controls skeletal muscle movements, including knee jerk reflex etc.

Question 11.
Depolarisation and Repoalarisation.
Answer:

Depolarisation	Repolarisation
It is the state in which the cell membrane change from positive to negative charged outside the cell and from negative to positive charge inside the cell.	It is the state in which the cell membrane change back its resting state, mean from negative to positive charge outside the cell and from positive to negative charge inside the cell.

Question 12.
Aqueous humor and vitreous humor.
Answer:

Aqueous humor	Vitreous humor
It occurs in aqueous chamber.	It occurs in vitreous chamber.
It is a watery fluid.	It is a jelly-like substance.
It is secreted by ciliary process.	It is apparently secreted by retina during the development of an eye.
It is continuously absorbed into the blood and replaced.	It is neither absorbed nor replaced.

Question 13.
Endolymph and Perilymph.
Answer:

Endolymph	Perilymph
In scala media.	In scala tympani and scala vestibuli
Extracellular fluid.	Ionic composition similar to CSF or plasma
Ionic composition similar to intracellular fluid. High K+, low Na+	Rich in Na+ and low in K+

Question 14.
Rod cells and Cone cells.
Answer:

Rods	Cones
The twilight vision is the function of rods.	The daylight vision and the colour vision are functions of cones.
The rods contain a purplish-red protein called the rhodopsin or visual purple, which contains a derivative of vitamin-A.	In the human eye, there are three types of cones which possess their own characteristic photopigments that respond to red, green and blue lights.

Long Answer Type Questions

Question 1.
Describe the structure of human brain and enumerate important function of each part of it.
Answer:
Brain:
The brain is the central information processing organ of our body and acts as the ‘command and control system of all body activities.

Diagram showing sagital section of the human brain

Brain controls the following activities
(i) The voluntary movements and balance of the body.
(ii) Functioning of vital involuntary organs, e.g., lungs, heart, kidneys, etc.
(iii) Thermoregulation, hunger and thirst.
(iv) Circardian (24 hrs) rhythms of our body.
(v) Activities of several endocrine glands and human behaviour.
(vi) It is also the site for processing of vision, hearing, speech, memory, intelligence, emotions and thoughts.

Location:
The brain is the anterior most part of the central neural system, which is located in the cranium (cranial cavity) of the skull.

Protective Coverings of the Brain:
It is covered by three membranes or meninges (cranial meninges)
(i) The outermost membrane, is duramater which is the tough fibrous membrane adhering close to the inner side of the skull.
(ii) The middle membrane, is very thin layer called arachnoid membrane (arachnoid mater).
(iii) The innermost membrane, the piamater is thin and very delicate, which is in contact with the brain tissue.

Knowledge Plus:
The human brain weighs from 1200-1400 g. Brain alone has about 2 billion neurons and trillions of interneuron connections.

Structure:
The human brain is divisible into three main parts
(i) Forebrain
(ii) Midbrain
(iii) Hindbrain
(i) Forebrain
The forebrain consists of
1. Olfactory lobes The anterior part of the brain is formed by a pair of short club-shaped structures, the olfactory lobes. These are concerned with the sense of smell.
2. Cerebrum It is the largest and most complex of all the parts of the human brain. A deep cleft divides the cerebrum longitudinally into two equal halves. These are termed as the left and right cerebral hemispheres. These hemispheres are connected by a large band of myelinated fibres the corpus callosum.

The outer cover of cerebral hemisphere is called cerebral cortex. The cerebral cortex is referred to as the grey matter due to its greyish appearance (as neuron cell bodies are concentrated here).

Lateral view of the brain showing the lobes of cerebral cortex, (a) Lateral view, (b) Drosal view.

The cerebral cortex is greatly folded. The upward folds, gyri, alternate with the downward grooves or sulci. Beneath the grey matter, there are millions of myelinated nerve fibers, which constitute the inner part of the cerebral hemisphere. The large concentration of medullated nerve fibres gives this tissue an opaque white appearance. Hence, it is called the white matter.

Lobes A very deep and a longitudinal fissure, separates the two cerebral hemispheres. Each cerebral hemisphere of the cerebrum is divided into four lobes, i.e., frontal, parietal, temporal and occipital lobes.
In each cerebral hemisphere, there are three types of functional areas
• Sensory areas It receives impulses from the receptors. Motor areas transmit impulses to the effectors.
• Association areas These are large regions that are neither clearly sensory nor motor in junction. They interpret the input, store the input and initiate a response in light of similar past experience. Thus, these areas are responsible for complex functions like memory, learning, • reasoning and other intersensory associations.

3. Diencephalon is the posterio-ventral part of the forebrain.
Its main parts are as follows
• Epithalamus is a thin membrane of non-nervous
tissue. It is the posterior segment of the diencephalon.
• The cerebrum wraps around a structure called thalamus, which is a major coordinating centre for sensory and motor signalling.
The hypothalamus, that lies at the base of thalamus contains a number of centres, which – control body temperature, urge for eating and drinking. It also contains several groups of neurosecretory cells, which secrete hormones called hypothalamic hormones.

The inner parts of cerebral hemispheres and a group of deeply associated structures like amygdala, hippocampus, etc., form a complex structure called limbic lobe or limbic system that is involved in the regulation of sexual behaviour, expression of emotional reactions, e.g., excitement, pleasure, rage and fear and motivation.

(ii) Midbrain
The midbrain is located between the thalamus hypothalamus of the forebrain and pons of the hindbrain. A canal called the cerebral aqueduct passes through the midbrain.
The dorsal portion of the midbrain mainly consists of two pairs (i.e., four) of rounded swellings (lobes) called corpora quadrigemina.

(iii) Hindbrain
The hindbrain consists of
(a) Cerebellum It is also called small brain and consists of three lobes, a central vermis and two lateral cerebellar hemispheres. The central core of each cerebellar hemisphere is formed by white matter and the arrangement of grey matter and white matter in the inner side have a characteristic tree like appearance called Arbor Vitae or tree of life.
(b) Pons Varolii It forms the floor of brain stem and serves as neuronal link between cerebral cortex and cerebellum. It consist of pontine nuclei, pneumotaxic area and apneustic area. Pontine nuclei are sites at which signals for voluntary movements are relayed into cerebellum. Both pneumotaxic and apneustic area control respiration.
(c) Medulla Oblongata It is the triangular part of brain whose roof is associated with overlying piamater to form the posterior choroid plexus. It contains cardiac centres (control rate and force heartbeat), vasomotor centres (control blood pressure by adjusting blood vessel diameter) and two respiratory centres (control rate and depth of breathing).

Ventricles of Brain:
The four cavities within brain are called cerebral ventricles.
These are given below
Cerebral ventricle and their location

Ventricle I, II and III are connected by foramen of monro, while ventricle III and IV are connected by cerebral aqueduct. Roof of ventricle IV contains a pair of lateral apertures foramina of luschka and a median aperture foramen of magendie.

The entire venticular system is lined the ependymal cells.

(a) Longitudinal frontal section of the brain and (b) Longitudinal sagittal section showing ventricles

Question 2.
Give an account of the mechanism of generation and propagation of a nerve impulse.
Or
Describe the mechanism of conduction of nerve impulse.
Answer:
Nerve impulse is a wave of bioelectric/electrochemical disturbance that passes along a neuron during conduction of an excitation.
Impulse conduction depends upon
(i) Permeability of axon membrane (axolemma).
(ii) Osmotic equilibrium (electrical equivalence) between the axoplasm and Extracellular Fluid (ECF) present outside the axon.
The generation of a nerve impulse is the temporary reversal of the resting potential in the neuron.

It occurs in following three steps
Resting Membrane Potential or Polarisation:
In a resting nerve fibre (a nerve fibre that is not conducting an impulse), the axoplasm (neuroplasm of axon) inside the axon contains high concentration of K and negatively charged proteins and low concentration of Na⁺.
(i) In contrast, the fluid outside axon contains a low concentration of K⁺ and a high concentration of Na⁺ and thus, forms a concentration gradient.
(ii) These ionic gradients across the resting membrane are maintained by the active transport of ions by the sodium-potassium pump, which transports 3Na⁺ outwards and 2K⁺ inwards (into the cell).
(iii) As a result, the outer surface of the axonal membrane possesses a positive charge, while its inner surface becomes negatively charged and therefore, is polarised.
(iv) The electrical potential difference across the resting plasma membrane is called as the resting potential. The state of the resting membrane is called polarised state.

Action Potential or Depolarisation:
When a stimulus of adequate strength (threshold stimulus) is applied to a polarised membrane, the permeability of the membrane to Na+ ions is greatly increased at the point of stimulation (site A).
1. This leads to a rapid influx of Na+ followed by the reversal of the polarity at that site, i.e., the outer surface of the membrane becomes negatively charged and the inner side becomes positively charged. The polarity of the membrane at the site A is thus, reversed and neuron at that point is said to be depolarised.

2. The electrical potential difference across the plasma membrane at the site A is called the action potential, (another name of nerve impulse).

3. At adjacent sites, e.g., site B, the membrane (axon) has positive charge (still polarised) on the outer surface and a negative charge on its inner surface.

4. The stimulated negatively charged point on the outside of the membrane sends out an electrical current to the positive point next to it. As a result, a current flows on the outer surface from site B to site A, while on the inner surface current flows from site A to site B.
This process (reversal) repeats itself over and over again and a nerve impulse is conducted throughout the length of the neuron.

Diagrammatic representation of impulse conduction through an axon

Repolarisation:
(i) The rise in the stimulus-induced permeability to, Na⁺ is extremely short lived. It is quickly followed by a rise in membrane permeability to K⁺.

(ii) Within a fraction of a second, Na⁺ influx stops andK⁺ outflow begins until the original resting state of ionic concentration is achieved. Thus, resting potential is restored at the site of excitation, which is called repolarisation of the membrane. This makes the fibre once more responsive to further stimulation.

(iii) In fact, until repolarisation occurs, neuron cannot conduct another impulse. The time taken for this restoration is called refractory period.

Reorientation:
Following repolarisation the membrane potential is restored at resting potential state, i.e. at 70 mV and the orientation of ions is also brought to normal. This is achieved by a process called reorientation. At the end of reorientation, normal polarity in respect of ionic distribution is reached.

Types of conduction:
Mechanism of conduction are different in myelinated and non-myelinated fiber. These are as follows
(a) Conduction along myelinated fiber
When an impulse travels along a myelinated neuron, depolarisation occurs only at the nodes of Ranvier. It leaps over the myelin sheath from one node to the next. This process, is called saltatory conduction.
This process accounts for the greater speed of an impulse travelling along a myelinated neuron than along a non-myelinated one. It is upto 50 times faster than the non-myelinated nerve fibre.

(b) Conduction along unmyelinated fiber
An action potential is generated is the membrane at the site of stimulation. The membrane undergoes depolarization by a rapid inflax of Na⁺ and then repolarization by an efflux of k⁺. Like this there is a wave of depolarization and repolarization in a forward direction in an electrifying speed.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 20 Locomotion and Movement Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 20 Question Answer Locomotion and Movement

Locomotion and Movement Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Multiple choice questions

Question 1.
The total no. of bones in human body is
(a) 106
(b) 206
(c) 306
(d) 246
Answer:
(b) 206

Question 2.
The contraction of muscle of shortest duration is seen in
(a) Jaw
(b) Eye lid
(c) Heart
(d) Intestine
Answer:
(b) Eye lid

Question 3.
What is the total number of ribs in human?
(a) 12
(b) 16
(c) 20
(d) 24
Answer:
(d) 24

Question 4.
Which unstriated muscle is entirely involuntary
(a) In the diaphragm
(b) In the eyelid
(c) At the base of external ear
(d) At the pylorous
Answer:
(a) In the diaphragm

Question 5.
Total no. of muscles in human is
(a) 639
(b) 936
(c) 369
(d) 669
Answer:
(a) 639

Question 6.
Cori cycle operates within one of the following organs
(a) Liver only
(b) Liver and muscle
(c) Muscle only
(d) None of these
Answer:
(b) Liver and muscle

Question 7.
One of the following muscles contains myoglobin, stores oxygen and rich is in mitochondria
(a) White muscle
(b) Red muscle
(c) Both
(d) None
Answer:
(b) Red muscle

Question 8.
How many vertebrae are present in man?
(a) 33
(b) 32
(c) 31
(d) 30
Answer:
(a) 33

Question 9.
Cervical vertebrae are present in
(a) Thorax
(b) Neck
(c) Abdomen
(d) Tail
Answer:
(b) Neck

Question 10.
Study of muscle is known as
(a) Musculogy
(b) Myology
(c) Arthrology
(d) Mycology
Answer:
(b) Myology

Question 11.
Knee joint is a
(a) Ball and socket joint
(b) Pivot Joint
(c) Hinge Joint
(d) Bicondylar joint
Answer:
(d) Bicondylar joint

Question 12.
Study of joints is called
(a) Osteology
(b) Mycology
(c) Arthrology
(d) Chondrology
Answer:
(c) Arthrology

Question 13.
Joint between femur and pelvic girdle is called
(a) Ball and socket joint
(b) Saddle joint
(c) Pivot joint
(d) Hinge joint
Answer:
(a) Ball and socket joint

Question 14.
Joint between the lower jaw and skull is called
(a) Gliding
(b) Hinge
(c) Perfect
(d) Gomphoses
Answer:
(d) Gomphoses

Question 15.
Which bone is present in pectoral girdle of all mammal
(a) Scapula
(b) Ilium
(c) Coracoid
(d) Pubis
Answer:
(b) Ilium

Question 16.
If ossification occurs in a tendon, which bone is formed.
(a) Sesamoid bone
(b) Replacing bone
(c) Membrane bone
(d) Dermal bone
Answer:
(a) Sesamoid bone

Question 17.
Which of the muscles bends the fore arm upward
(a) Biceps
(b) Triceps
(c) Gastrocremius
(d) Gluteus maximus
Answer:
(b) Triceps

Question 18.
Which bone is the longest in the body
(a) Fibula
(b) Femur
(c) Tibia
(d) Ulna
Answer:
(b) Femur

Question 19.
Which bone of man is not used for protection and support in the body
(a) Stapes
(b) Atlas
(c) Ribs
(d) Scapula
Answer:
(a) Stapes

Question 20.
The joint between carpals and radius and ulna is called
(a) Condylar joint
(b) Immovable joint
(c) Gliding joint
(d) Saddle joint
Answer:
(d) Saddle joint

Question 21.
Articulation of odontoid process of axis and atlas vertebrae is an example of
(a) Gliding joint
(b) Ball & socket joint
(c) Pivot joint
(d) Hinge joint
Answer:
(c) Pivot joint

Question 22.
Articulation of metacarpal of thumb with its carpal is an example of
(a) Saddle joint
(b) Hinge joint
(c) Pivot joint
(d) Gliding joint
Answer:
(a) Saddle joint

Question 23.
Articular cavity the pectoral girdle is.
(a) Acetabulum
(b) Glenoid cavity
(c) Neural canal
(d) Foramen of Monro
Answer:
(a) Acetabulum

Question 24.
Name of the joint at acetabulum
(a) Hip joint
(b) Shoulder joint
(c) Knee joint
(d) Elbow joint
Answer:
(a) Hip joint

Question 25.
Sutures present between various bones of the skull are
(a) Carlilaginous joint
(b) Synovial joint
(c) Hinge joint
(d) Fibrous joint
Answer:
(d) Fibrous joint

Question 26.
Number of true ribs and floating ribs are
(a) 6 and 3
(b) 0 and 2
(c) 9 and 4
(d) 20 and 4
Answer:
(d) 20 and 4

Question 27.
Which joint occurs between humerus and radius and ulna
(a) Pivot joint
(b) Hinge joint
(c) Sliding joint
(d) Ball & Socket joint
Answer:
(b) Hinge joint

Question 28.
Functions of long bones in mammal is to provide
(a) Support
(b) Support and production of RBCs
(c) Support and production of WBC
(d) Support and production of RBCs and WBCs
Answer:
(a) Support

Question 29.
Epiphyseal plate at the extremity of long bones help in
(a) Elongation of bone
(b) Bone moulding
(c) Bone formation
(d) Formation of Haversian canals
Answer:
(a) Elongation of bone

Question 30.
Muscle that bends one part over another is
(a) Extensor
(b) Flexor
(c) Adductor
(d) Abductor
Answer:
(c) Adductor

Question 31.
Malleus, incus and stapes occur in
(a) Skull
(b) Middle ear
(c) Pectoral girdle
(d) Pelvic girdle
Answer:
(b) Middle ear

Express the Following Statements in One Word or More Words, Wherever Necessary.

Question 1.
What is the name of the contractile unit of a skeletal muscle fibre.
Answer:
Myofibril

Question 2.
What is myology?
Answer:
Study of muscles

Question 3.
Where do you see pivot joint?
Answer:
Atlas-axis joint

Question 4.
Give an example of gomphosis.
Answer:
Tooth-socket articulation

Question 5.
What is the alternate name of breast bone?
Answer:
Sternum

Question 6.
In which part of the endo skeleton you come across sutures?
Answer:
Skull

Question 7.
What do you call the bones of the wrist?
Answer:
Carpals

Question 8.
How many lumber vertebrae are there in human?
Answer:
5

Question 9.
What is a vertebrate limb having five digits known as?
Answer:
Pentadoctyl limb

Question 10.
What is the alternate source of energy in a skeletal muscle?
Answer:
Thosphocreatine

Fill in the Blanks with Appropriate Words

Question 1.
……………. muscle contracts during flexon of the elbow joint.
Answer:
Biceps

Question 2.
Hip joint is an example of …………… joint.
Answer:
Multiaxial/Spheroidal

Question 3.
The centrum of mammalian vertebrae is of …………… type.
Answer:
Acoelus

Question 4.
Each T band of the muscle fiber contains a dense line at the centre, known as ………… .
Answer:
Z-line

Question 5.
…………. muscle relaxes the elbow joint.
Answer:
Triceps

Question 6.
A muscle gets fatigued by an accumulation of ………………. .
Answer:
Lactic acid

Question 7.
Myoglobin is found in ……………. .
Answer:
Red muscles

Question 8.
Knee joint is a ………… type of joint.
Answer:
Bicondylar

Question 9.
Contraction of ………… muscle helps in lifting heavy weight.
Answer:
Biceps

Question 10.
The stretch of a myofibril between two Z-lines is known as ………….. .
Answer:
sarcomere

Question 11.
The shoulder joint is classified as …………. joint.
Answer:
Ball and socket

Question 12.
Stiffening of the body after death of a person is known as ………… .
Answer:
Rigor mortis

Question 13.
There are ……….. number of vertebrae in the human vertebral column.
Answer:
26

Question 14.
Total number of bones in the human skull are …………… .
Answer:
22

Question 15.
Total number of metacarpals in the wrist of man is …………… .
Answer:
5

Question 16.
There are …………. cervical vertebrae in all mammals.
Answer:
7

Short Answer Type Questions

Answer each within 50 words.

Question 1.
What do you understand by a pentadactyl limb?
Answer:
Pentadactyl limb refers to the limb having five digits, e.g., humans.

Question 2.
Enlist the constituent parts of the appendicular skeletal system of human.
Answer:
Appendicular skeleton in human comprises of 126 bones including pectoral and pelvic girdle; limb bones-forelimb and hindlimb.

Question 3.
Enlist the constituent parts of the axial skeletal system of human.
Answer:
Axial skeleton in human consist of 80 bones including that of skull, vertebral column, ribs and sternum.

Question 4.
What is the role of troponin in muscle contraction?
Answer:
The sequence of events leading to contraction is initiated by a signal in the Central Nervous System (CNS), either from the brain (voluntary activity) or from spinal cord (reflex activity) via a motor neuron. A motor neuron along with the muscle fibres connected to it, forms a motor unit and the action potential is conveyed to a motor end plate at neuromuscular junction, i.e., it is the junction between a motor neuron and sarcolemma of muscle fibre.

Question 5.
What is a synovial joint? Give two examples What is a fibrous joint? Explain with an example.
Answer:
Each articular surface is cover by a layer of hyaline cartilage.

A considerable movement is allowed at all synovial joints. It is because there is present fluid-filled synovial cavity between articulating surface of bones. These are also surrounded by tubular articular capsule.

The capsule consists of two layers, i.e., outer fibrous capsule and inner synovial membrane which ‘secretes synovial fluid’ that lubricates and is responsible for providing nourishment to articular cartilage.

Question 6.
Differentiate between rheumatoid arthrit and osteoarthritis.
Answer:

Rheumatoid arthritis	Osteoarthritis
It is infammation of synovial membrane in synovial joints.	It is progressive erosion of articular cartilage at synovial joint.
It can occur at any age.	Usually occur in old age.

Question 7.
What are myofilaments? How many types of myofilaments are present in a myofibril?
Answer:
Myofilaments are large number of parallely arranged muscle fibres. These are the characteristic feature of muscle fibres. There are usually two type of myofilaments in a myofibril namely thick (myosin) and thin (actin, troponin, etc.) myofilaments.

Question 8.
Describe the role of troponin and tropomyosin in skeletal muscle contraction.
Answer:
During muscle contraction, tropomyosin moves laterally, thereby freeing the myosin head binding sites of actin.
Troponin contain Ca²⁺ binding sites and tropomyosin binding subunit. It binds to calcium during muscles contraction.

Question 9.
What is the role of phosphocreatine in the skeletal muscle contraction?
Answer:
Phosphocreatine acts as a reserve energy currency in mitochondria of muscle fibres and helps to form ATP. This energy rich compound transfer its phosphate group to ADP and form ATP.

Question 10.
What is sarcoplasmic reticulum? Where it is found and what is its function?
Answer:
Sarcoplasmic reticulum in myofibrils are in the form of tubules which joins to form terminal cisternae present between each anisotropic (A) and isotropic (I) bands. The sarcoplasmic reticulum in the form of tubules and terminal cisternae and transverse tubules constitutes sarco-tubular system.

Question 11.
What is muscle twitch ?
Answer:
Muscle twitch : It is the contraction of muscle fibre stimulated by nerve impulse. It is the isolated contraction of muscle, immediately after which muscle fibre relaxes.

Question 12.
What is an antagonistic muscle?
Answer:
Antagonistic muscles: These muscles acts in opposition to other muscles, e.g.; flexor/extensor, adductors/abductors, etc.

Question 13.
What is synovial fluid?
Answer:
Synovial fluid : It is secreted by the synovial membrane of synovial joint. This fluid fills the articular cavity and acts as a lubricant at articular surface and thus absorb friction.
It is dialyzed blood plasma containing hyaluronic acid secreted by synovial membrane.

Question 14.
What is the function of supinator muscle?
Answer:
Supinator muscle of the forearm and the biceps brachii of the upper arm supinate the forearm by pulling on the radius. They rotate the radius in the opposite direction of pronator muscle, moving the distal end of radius back to its position on the lateral side of the wrist.

Differentiate between

Question 1.
Appendicular skeleton and Axial skeleton
Answer:

Appendicular skeleton	Axial skeleton
Present along transverse axis.	Present along vertical axis.
Consists of 126 bones.	Consists of 80 bones
Comprises limb bones and girdles.	Comprises bones of skull, vertebral column, sternum and ribs.

Question 2.
Synovial joint and Solid joint
Answer:

Solid joint	Synovial joint
The bones are held together at the joint by bundles of collagen fibres.	The bones are held together at the joint by an articular capsule made up of bands of fibrous tissue and ligaments.
The articular surfaces of the bones are not covered by any cartilage.	The articular surface of the bones are covered by cartilage called articular cartilage.
A space is not present in the joint.	A space filled with synovial fluid is found in the joint.
The joint does not allow any movement.	The joint allows free movement.

Question 3.
Actin and Myosin
Answer:

Myosin filaments (Thick myofilaments)	Actin filaments (Thin myofilaments)
Found only in A-band of sarcomere.	Found in-both A and l-bands.
Thicker (0.01 mm), but longer (4.5 mm) than actin filaments.	Thinner (0.005 mm), but shorter (2-2.6 mm) than myosin filaments.
Cross bridges present, hence have rough surface.	Cross bridges absent, hence have smooth surface.
Fewer than actin filaments.	More numerous than myosin filaments, six of them surround each myosin filaments.
Free at both the ends.	Free at one end and are joint to Z-line by other end.
Consist of 2 proteins: myosin and meromysin.	Consist of 3 proteins: actin, tropomyosin and tropinin.
Do not slide during muscle contraction.	Slide into H-zone during muscles contraction.

Question 4.
Rheumatoid arthritis and Osteoarthritis
Answer:

Rheumatoid arthritis	Osteoarthritis
It is infammation of synovial membrane in synovial joints.	It is progressive erosion of articular cartilage at synovial joint.
It can occur at any age.	Usually occur in old age.

Question 5.
Red muscle fibers and White muscle fibers
Answer:

Red Muscle Fibres	White Muscle Fibres
They are dark red muscle fibres due to the presence of abundant myoglobin in them. Hence they are called slow twitch or type I fibres.	They are pale or whitish as they have less myoglobin. Hence they are called fast twitch or type II fibres.
Mitochondria are more in number, but they have less sarcoplasmic reticulum.	Mitochondria are few in number, but amount of sarcoplasmic reticulum is high.
They depend on aerobic process for energy.	They depend on anaerobic process for energy.
They have slow rate of contraction for long periods.	They have fast rate of contraction for short periods.
e.g., extensor muscle of the human back, soleus muscles of leg.	e.g., eyeball or extra-occular muscles.

Question 6.
Biceps and Triceps
Answer:

Biceps	Triceps
Made up of two muscle bundles-long head and short head.	Made up of three muscle bundles-lateral head, long head and medial head.
They are flexor.	They are extensor
It contracts and bends arm at elbow.	It contract and straighten the arm at elbow.

Question 7.
Skeletal muscle and Cardiac muscle
Answer:

Skeletal Muscle	Cardiac Muscles
It is found in limbs, tongue, pharynx and beginning of oesophagus.	It is found in the wall of the heart, pulmonary veins and superior Vena Cava,
Fibres are unbranched.	Fibres are branched.
It is multinucleated.	It is uninucleated.
No oblique bridges and intercalated discs.	Oblique bridges and intercalated discs are present.
It soon gets fatigued.	It never gets fatigued.
It is voluntary in action.	It is involuntary in action.

Question 8.
Involuntary muscle and Voluntary muscle
Answer:

Involuntary Muscles	Voluntary Muscles
Associated with nerves of ANS.	Associated with nerves under voluntary control.
Cannot be controlled conciously	Can be controlled conciously
Contraction is rhythmic and slow.	Contraction is rapid and forceful
e.g. Smooth and cardiac muscles.	e.g. skeletal muscles.
They are are visceral	They are attached to bones.

Question 9.
Striated muscle and Unstriated muscle
Answer:

Striated Muscles	Unstriated Muscles
Voluntary in action	Involuntary in action
Muscle fibres are long and cyclindrical with blunt ends.	Long, spindle shaped with pointed ends
Multi nucleated.	Uninucleated
Sarcomerepresent	Sarcomere absent.
e.g. biceps muscle	e.g. intestinal muscles.

Long Answer Type Questions

Question 1.
Describe the sliding filament theory of skeletal muscle contraction.
Answer:
Biochemical Events during Muscle Contraction:
The sequence of events leading to contraction is initiated by a signal in the Central Nervous System (CNS), either from the brain (voluntary activity) or from spinal cord (reflex activity) via a motor neuron. A motor neuron along with the muscle fibres connected to it, forms a motor unit and the action potential is conveyed to a motor end plate at neuromuscular junction, i.e., it is the junction between a motor neuron and sarcolemma of muscle fibre.

A neurotransmitter (acetylcholine) is released at the junction by the neural signal which generates an action potential in the sarcolemma. This spreads and causes the release of calcium ions into sarcoplasm. Calcium plays a key regulatory role in muscle contraction. Increase in calcium ions level leads to binding of Ca⁺ ions to the troponin subunit on actin filament. This removes the masking of active sites for myosin.

Formation of Cross-Bridge:
An ATP molecule joins the active site on myosin head of myosin myofilament. These heads contain an enzyme, myosin ATPase that along with Ca²⁺ and Mg²⁺ ions catalyses the breakdown of ATP.

The energy is transferred to myosin head, which energises and straightens to join an active site on actin myofilament, forming a cross bridge.

The energised cross-bridges produce a power stroke and move, causing the attached actin filaments to move towards the centre of A-band. The Z-line is also pulled inwards causing shortening of sarcomere, i.e., contraction. It is clear from the above explanation that during contraction, A-bands retain the length, while I-bands get reduced.

After the power stroke, the myosin head releases ADP and Pi, relaxes to its low energy state. The head detaches from actin myofilaments when new ATP joins it (cross-bridge broken).

The cross bridge cycle that causes sliding of myofilaments and hence muscle contraction

In repeating cycle, the free head cleaves the new ATP.
The cycles of cross-bridge formation and breakage is repeated causing further sliding. As ATP is required to dislodge ADP, in the absence of it, ADP remain bounded to myosin head. The myosin head further remain permanently bound to action and hence, the muscle is never relaxed. This condition is called rigor mortis. If occurs after death when there is complete depletion of ATP and phosphocreatine.

Sliding filament theory of muscle contraction (movement of the thin filaments and the relative size of the I-band and H-zones

Muscle Relaxation:
After contraction, the calcium ions are pumped back to the sarcoplasmic cisternae, blocking the active sites on actin myofilaments. The Z-line returns to original position, i.e. relaxation of muscle fibre takes place. If the movement of Ca²⁺ into the reticulum is inhibited, relaxation doesn’t occur. The condition of sustained contraction is called contracture.

Energy sources:
The immediate source of energy for contraction is ATP, produced in carbohydrate, protein and lipid catabolism. However, during heavy exercise, ATP may be used faster than it is produced. A rapid renewal of ATP is extremely necessary to keep the contration process on. Under this situation phosphocreatine, a reserve energy currency in mitochondria of muscle fibers, serves to form ATP. This energy-rich compound transfers its phosphate group to ADP, consequently forming ATP.

This phosphate transfer reaction is catalyzed by an enzyme called creatin kinase, also called creatine phosephokinases, present in the skeletal muscle fiber. When the muscle is at the rest. ATP in the mitochondrion transfers its phosphate group to creratine forming phosphocreatine. Thus, there is a build up of phosphocreatine to serve during exigencey. its concentration is more than three times the concentration of ATP in a muscle cell.

Question 2.
Draw a neat labeled diagram of a sarcomere of skeletal muscle fiber (No description is necessary).
Answer:

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 19 Excretory Products and Their Elimination Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 19 Question Answer Excretory Products and Their Elimination

Excretory Products and Their Elimination Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Multiple Choices Questions

Question 1.
The organs of excretion in the cockroach are
(a) Flame cells
(b) Green gland
(c) Nephridia
(d) Malpighian tubules
Answer:
(d) Malpighian tubules

Question 2.
Birds eliminate their nitrogenous wastes in the form of
(a) ammonia
(b) urea
(c) uric acid
(d) amino acids
Answer:
(c) uric acid

Question 3.
Ornithine cycle occurs in
(a) liver
(b) kidney
(c) brain
(d) skin
Answer:
(a) liver

Question 4.
Ornithine cycles synthesises
(a) ammonia
(b) urea
(c) uric acid
(d) xanthine
Answer:
(b) urea

Question 5.
What is the main nitrogenous waste product in reptile?
(a) ammonia
(b) urea
(c) uric acid
(d) hippuric acid
Answer:
(c) uric acid

Question 6.
Urea is formed from the breakdown of
(a) carbohydrates
(b) proteins
(c) fats
(d) nucleic acids
Answer:
(b) proteins

Question 7.
In man, uric acid is formed from the break down of
(a) carbonydrates
(b) proteins
(c) fats
(d) nucleic acids
Answer:
(d) nucleic acids

Question 8.
Desert mammals have in their nephrons.
(a) long loops of Henle
(b) long proximal convoluted tubules
(c) long distal convolutions
(d) long collecting ducts
Answer:
(a) long loops of Henle

Question 9.
ADH exercises its action on part of the nephron.
(a) PCT
(b) Henle’s loop
(c) DCT
(d) glomerulus
Answer:
(c) DCT

Question 10.
Most aquatic animals are
(a) ammonotelic
(b) ureotelic
(c) ureotelic
(d) aminotelic
Answer:
(a) ammonotelic

Question 11.
What is diabetes insipidus due to?
(a) loss of glucose by the urine
(b) deficiency of ADH
(c) deficiency of insulin
(d) All of the above
Answer:
(b) deficiency of ADH

Question 12.
Which hormone is secreted from juxtaglomerular apparatus of kidney?
(a) renin
(b) angiotensin
(c) adrenalin
(d) calcitrol
Answer:
(a) renin

Question 13.
Reabsorption of sodium and chloride occurs in
(a) Ascending limb of Henle’s loop
(b) Proximal convoluted tubule
(c) Descending limb of Henle’s loop
(d) Distal convoluted tubule
Answer:
(b) Proximal convoluted tubule

Question 14.
Human kidney is
(a) pronephric
(b) mesonephric
(c) metanephric
(d) opisthonephric
Answer:
(b) mesonephric

Question 15.
Longer loop of Henle is meant primarily for increased absorption of
(a) glucose
(b) water
(c) potassium
(d) amino acids
Answer:
(b) water

Short Answer Type Questions

Write briefly on the following (within 50 words each)

Question 1.
Ammonotelism
Answer:
Ammonia is the most toxic form of nitrogenous waste, it requires large amount of water for its elimination. The organisms that excrete ammonia are called ammonotelic and this process of eliminating ammonia is known as ammonotelism. Examples of ammonotelic animals are bony fishes, aquatic amphibians and aquatic insects. Since, ammonia, is readily soluble in water and is generally excreted by diffusion across body surfaces or through gill surfaces (in fish) as ammonium ions the ammonotelism is commonly found in aquatic animals.

Question 2.
Ureotelism
Answer:
The process of excreting urea is called ureotelism. Animals, which do not live in high abundance of water convert ammonia produced in the body into urea (in the liver) and release it into the blood, which is filtered and excreted out as urine by the kidneys.
Examples of ureotelic animals are mammals, many terrestrial amphibians and marine fishes.

Question 3.
Uricotelism
Answer:
The process of excreting uric acid is called uricotelism. Uric acid, being the least toxic nitrogenous waste can be removed with a minimum loss of water from the animal body.
Thus, it is excreted in the form of pellet or paste (i.e., semisolid form). Normally, the animals which live in desert exhibit uricotelism.
Examples of uricotelic animals are reptiles, birds, land snails and insects.

Question 4.
Role of the Malpighian tubule in the excretion in cockroach.
Answer:
Malpighian tubules are principle excretory organs of a cockroach. These tubules consists of two distinct regions, i. e. the distal half (secretory) and the proximal portion (absorptive in function).
The distal region is alkaline, concerned with the secretion of urates of potassium and sodium extracted from the surrounding haemolymph.
The proximal region is acidic due to CO₂ secretion.
The uric acid is therefore precipitated while sodium and potassium Eire reabsorbed as bicarbonates to be used again. The urine passes to ileum, excreted via rectum along with the faeces where excess water is absorbed from them.

Question 5.
Structure of the mammalian nephron
Answer:
The LS of a mammalian kidney shows differentiation into outer cortex and inner medulla.

LS of kidney

Inside the kidney, the ureter is expanded as a funnel-shaped cavity called pelvis. The free end of pelvis has number of cup-like cavities called major calyces (sing, calyx) and minor calyces.
Medulla projects into the calyces as conical processes, called renal pyramids or medullary pyramids. The tip of pyramids are called renal papillae. The cortex spreads in between medullary pyramids as renal columns called columns of Bertini.

Microscopic Structure:
Each kidney is composed of numerous (nearly one million) complex tubular structures called nephrons. These are the functional units of kidney.
Structure of Nephron or Uriniferous Tubule
Each nephron consists of two parts, i.e., the Malpighian body or renal corpuscle and the renal tubule.

Malpighian Body or Renal Corpuscle Glomerulus along with Bowman’s capsule is called the Malpighian body or renal corpuscle which filters out large solutes from the blood and delivers small solutes to the renal tubule for modification.

Malpighian body (renal corpuscle)

Question 6.
Ultrafiltration
Answer:
Ultrafiltration or Glomerular Filtration
The first step of urine formation is the filtration of blood. It is carried out by the glomerulus. That is why this step is called glomerular filtration.
Kidneys filter about 1100-1200 mL of blood per minute, which constitute roughly 1/5th of the blood pumped out by each ventricle of the heart in a minute.
The glomerular capillary blood pressure causes filtration of blood through three layers, i.e.,

• the endothelium of glomerular blood vessels.
• the epithelium of Bowman’s capsule.
• a basement membrane (present between the above mentioned two layers).

The podocytes (epithelial cells of Bowman’s capsule) are arranged in such a manner, so that some minute spaces called filtration slits or slit pores occur between them.

Diagram representing the path taken by fluid (glomerular filtrate) during its passage from the plasma in a glomerular capillary of the lumen of a renal capsule

Question 7.
Selective reabsorption
Answer:
Selective Reabsorption:
This is the second step in the formation of urine from filtrate. The urine released is 1.5 L as compared to the volume of the filtrate formed per day (180 L). It suggests that as much as 99% of the material in the filtrate is reabsorbed by the renal tubules. Thus, the process is called reabsorption. Depending upon the types of molecules being reabsorbed, movements into and out of epithelial cells in different segments of nephron occur either by passive transport or active transport.
These are described as follows
(i) Water and urea, are reabsorbed by passive transport (i.e., water is reabsorbed by osmosis and urea by simple diffusion).
(ii) Glucose and amino acids are reabsorbed by activi transport.
(iii) The reabsorption of Na⁺, occurs both by passive and active transport.

Question 8.
Henle’s loop
Answer:
Henle’s Loop:
Reabsorption in Henle’s loop is minimum, besides this, it plays an important role in maintaining the high osmolarity of medullary interstitial fluid. Two portions of Henle’s loop, play different role in osmoregulation. These are as follows
1. Descending Limb of Loop of Henle Water is reabsorbed here due to increasing osmolarity of interstitial fluid but, sodium and other electrolytes are not reabsorbed here. This concentrates the filtrate as it moves down.

2. Ascending Limb of Loop of Henle This segment is impermeable to water, but permeable to K⁺,Cl^– and Na⁺ and partially permeable to urea. Thus, in the thick ascending limb of the loop of Henle Na⁺, K⁺, Mg²⁺ and Cl are reabsorbed.
Therefore, as the concentrated filtrate pass upward, it gets diluted due to the passing out of electrolytes to the medullary fluid of kidney

Question 9.
Counter current mechanism
Answer:
Kidney of higher vertebrates (such as mammals, birds and man) has the ability of absorbing more and more water from tubular fdtrate to conserve water and make the urine more concentrated.
This can be achieved by a special mechanism known as counter current mechanism. The basic concept and this mechanism is as follows

Question 10.
Kidney as an endocrine organ
Answer:
Kidney as an endocrine glands The mammalian kidney performs many endocrine functions in the body. The kidney produces three hormones, i.e.
(a) Erythropoietin a peptide hormone which controls erythrocyte production in the body.
(b) Calcitriol the final activation of vitamin-D to active hormone calcitriol occurs in the kidneys.
(c) Renin is the part of the Renin-Angiotensin- Aldosterone System (RAAS). It controls the formation of angiotensin that influences blood pressure and sodium balance in the body.
Kidneys also synthesise prostaglandins, which Eiffect many processes occuring in the kidneys.

Question 11.
Secretion
Answer:
It is also an important step in urine formation. Certain chemicals in the blood that are not removed by filtration . from the glomerular capillaries are removed by this process of tubular secretion.
Acid base
It helps in the maintenance of ionic and acid-base balance of body fluids by removing chemicals like foreign bodies, ions (K⁺ , H⁺ , NH⁺₄) and molecules (medicines), etc., that are toxic at elevated levels.

Question 12.
Acid-base balance
Answer:
Acid base
It helps in the maintenance of ionic and acid-base balance of body fluids by removing chemicals like foreign bodies, ions (K⁺ , H⁺ , NH⁺₄) and molecules (medicines), etc., that are toxic at elevated levels.

Question 13.
Role of liver in excretion
Answer:
Role of Liver:
It changes the decomposed haemoglobin of the worn out red blood corpuscles into bile pigments, i.e., bilirubin and biliverdin. These pigments pass into the alimentary canal with the bile for elimination in the faeces. The liver also excretes cholesterol, steroid hormones, certain vitamins and drugs via bile.

Liver deaminates the excess and unwanted amino acids, producing ammonia, which is quickly combined with CO₂ to form urea in urea cycle or Ornithine cycle, which is further removed by the kidneys.

Question 14.
Orinithine cycle/Urea cycle
Answer:
Urea formation occurs in the liver by urea cycle or Ornithine or Kreb’s-Henseleit cycle. The excess amino acids in the body undergoes deamination in the liver and forms ammonia. Being highly toxic, ammonia is immediately converted to the less toxic urea by urea cycle. Urea cycle involves three amino acids, i.e. ornithine, citrulline and arginine.

Steps
(a) Ornithine reacts with ammonia and C02 forming citrulline and water.
(b) Citrulline combines with more ammonia forming arginine and water.
(c) Arginine then transforms into urea and ornithine in presence of enzyme arginase water.

Question 15.
Dialysis
Answer:
When the kidneys can no longer excrete water and ions at rates that maintain body balance of these substances nor they can excrete the wastes as fast as they are produces a technique called dialysis is used to cure kidney failure haemodialysis is carried out in which blood is filtered. Dialysis means separation of substances using a semi or a selectively permeable membrane.

Question 16.
Storage excretion in cockroach
Answer:
In cockroach, urate cells are found. These cells absorb and store uric acid throughout the life. This is called storage excretion as they remain stored in the cells of corpora adipose.

Question 17.
Renin-angiotensin system
Answer:
As blood pressure/glomerular blood flow /GFR decreases, the cells of the JGA release the enzyme renin.
Renin converts angiotensinogen in blood to Angiotensin I and Angiotensin II (active form). This mechanism is generally known as the Renin-angiotensin mechanism. Renin is the rate limiting factor in this system.

Summary of the renin angiotension aldosterone system

Question 18.
Obligatory water loss
Answer:
The minimal amount of fluid loss that can occur from the living body is known as the obligatory water loss.
Human kidney have the ability to produce a hyperosmotic urine that enables the body to survive without water for a long period. The human kidneys can produce a maximal urine concentration of 1400 m osmol/L., approx, five times the osmolarity of the blood plasma; which is 300 m osmol/L. Urea, sulfate, phosphate and other waste products and ions excreted each day amount to approximately 600 m osmol/L. The minimum volume of water in which the above quantity of solute can be dissolved and excreted in the urine is
= \(\frac{600 \mathrm{~m} \mathrm{Osmol} / \text { day }}{1400 \mathrm{~m} \mathrm{Osmol} / \mathrm{L}}\)
= 0.444 L/day
This volume of urine is referred to the ‘obligatory water loss’. The loss of this minimal volume of urine contributes to dehydration when a person goes without water for a long period.

G Explain the Following

Question 19.
Net filtration pressure
Answer:
Net Alteration pressure It is the pressure that helps to move filterate from the glomerulus into Bowman’s capsule. It is a combination of glomerular hydrostatic pressure, capsular hydrostatic pressure and osmotic colloid pressure.

Question 20.
Glomerular filtration rate
Answer:
Glomerular Filtration Rate:
The amount of the filtrate formed by the kidneys per minute is called Glomerular Filtration Rate (GFR). In a healthy person it was found approximately 125 mL /min, i. e., 180 L/day. GFR is regulated by one of the efficient mechanism carried out by Juxtaglomerular Apparatus (JGA).
JGA is a special sensitive region formed by cellular modifications in the distal convoluted tubule and the afferent arteriole at the location of their contact.
This apparatus includes
(i) granular juxtaglomerular cells in the afferent arteriole.
(ii) macula densa cells of DCT.
(iii) agranular lacis cells situated in between the above two.

Question 21.
Obligatory reabsorption of water
Answer:
Obligatory reabsorption of water Eighty five percent of the water reabsorption occurs irrespective of the body water balance and is called obligatory reabsorption of water. It takes place in proximal and distal tubules.

Question 22.
Role of ADH in water reabsorption
Answer:
Excessive loss of fluid from the body activates osmoreceptors present in blood vessels of hypothalamus, thus stimulating it to release ADH or vasopressin from the neurohypophysis. ADH release increases water reabsorption from DCT. An increase in body fluid volume switches off the osmoreceptors and suppresses the ADH release to complete the feedback. ADH also causes constrictory effects on blood vessels of glomerulus thus, increasing pressure for faster filtration.

Question 23.
Obligatory water loss
Answer:
The minimal amount of fluid loss that can occur from the living body is known as the obligatory water loss.
Human kidney have the ability to produce a hyperosmotic urine that enables the body to survive without water for a long period. The human kidneys can produce a maximal urine concentration of 1400 m osmol/L., approx, five times the osmolarity of the blood plasma; which is 300 m osmol/L. Urea, sulfate, phosphate and other waste products and ions excreted each day amount to approximately 600 m osmol/L. The minimum volume of water in which the above quantity of solute can be dissolved and excreted in the urine is
= \(\frac{600 \mathrm{~m} \mathrm{Osmol} / \text { day }}{1400 \mathrm{~m} \mathrm{Osmol} / \mathrm{L}}\)
= 0.444 L/day
This volume of urine is referred to the ‘obligatory water loss’. The loss of this minimal volume of urine contributes to dehydration when a person goes without water for a long period.

Question 24.
Functions of vasa recta
Answer:
Function of vasa recta
(i) Vasa recta plays an important role in counter-current mechanism.
(ii) Vasa recta also regulates the blood flow in kidney.

Differentiate between

Question 25.
Ammonotelism and Ureotelism
Answer:
Ammonotelism and Ureotelism

Ammonotelism	Ureotelism
(a) The chief excretory waste product is ammonia.	The chief nitrogenous waste product is urea.
(b) Ammonia is highly soluble in water and is produced by deamination of amino acids.	Ureajs less soluble in water and is produced by urea cycle in liver via arginine.
(c) Ammonia waste is highly toxic and requires large quantity of water for elimination.	Urea is less toxic and does not require high abundance of water for elimination.
(d) The animals performing ammonotelism are called as ammonotelic.	The animals carrying out ureotelism are called ureotelic.
e.g. Protozoa, sponges, coelenterates, prawn, etc.	e.g. Mammals, earthworm, cartilaginous fish.

Question 26.
Ureotelism and Uricotelism
Answer:
Ureotelism and Uricotelism

Ureotelism	Uricotelism
The process of excreting urea is called ureo elism.	The process of excreting uric acid as waste product is called uricotelism.
Urea is less toxic than ammonia containing nitrogenous waste products.	Uric acid is the least toxic nitrogenous waste product.
Urea is formed in the liver by detoxification of ammonia.	Uric acid is formed mainly from the purines in liver cells.
It is characteristic excretory process of mammals, cartilaginous fishes and amphibians, etc. Such animals are called as ureotelic.	Uricotelism is characteristic of terrestrial reptiles insects and all birds. Such animals carrying out uricotelism are called uricotelic.

Question 27.
Cortical nephron and juxamedullary nephron
Answer:
Cortical nephron and juxamedullary nephron

Cortical nephron	Juxtamedullar neptron
They form 80% of the total nephron count.	These constitute 20% of total nephron count.
Cortical nephrons are smaller in size.	Juxtamedullary nephrons are larger in size.
The loop of Henle is too short, extends very little into the medulla.	The loop of Henle is very long and runs deep into the medulla.
Cortical nephrons lie in the renal cortex of kidney.	Juxtamedullary nephrons are found in the medulla of kidney.

Question 28.
Selective reabsorption and secretion.
Answer:
Selective reabsorption and secretion.

Tubular reabsorption	Tubular secretion
It involves the absorption of water and useful solutes from the glomerular filtrate into the blood.	It refers to the passage of waste materials from blood into the filtrate or nephrons.
It occurs by back diffusion and active transport.	It takes place only by active transport.
It occurs mostly in PCT.	It occurs mostly in DCT.
It does not occur in animals that lack glomerulus (e.g, marine fish and desert animals).	It is the only mode of excretion in animals that lack glomerulus.

Question 29.
Haemodialysis and peritoneal dialysis
Answer:
Haemodialysis and peritoneal dialysis

Haemodialysis	Peritoneal dialysis
Haemodialysis involves an artificial membrane in a dialyser machine.	Peritoneal dialysis uses the lining of the individual’s own abdominal cavity (peritoneum) as a dialysing membrane.
The process takes about 6-8 hours and is done atleast twice a week.	The peritoneal dialysis usually involves 4-6 exchanges of dialysing fluid per day.
It increases the risk of bloodstream related infections.	It increases the risk of an infection of peritoneum lining called peritonitis.

Question 30.
Acute renal failure and chronic renal failure
Answer:
Acute renal failure and chronic renal failure

Acute Renal Failure	Chronic Renal Failure
It is the sudden failure or impairment of kidney functions.	Chronic failure is usually a long term diseases that slowly damages and reduces the function of kidneys over time.
ARF is usually reversible with adequate medical attention.	CRF is irreversible due to its prolonged occurence and permanent effects.
Most common cause of ARF is, hypovolaemia (a state of decreased blood volume).	Chronic glomerulonephritis diabetic nephropathy are common cause of chronic renal failure.
In ARF patients, the output of the urine is reduced.	In CRF, the patients suffer from constitutional symptoms or its long term complications.

Question 31.
Ammonotelism and Aminotelism
Answer:
Ammonotelism and Aminotelism

Ammonotelism	Aminotelism
The elimination of nitrogenous wastes in the form of ammonia from the body.	It is the elimination of nitrogenous waste mainly in the form of amino acids.
Ammonia is formed in the liver.	Amino acids are formed due to protein digestion in body.
The animals carrying out ammonotelism are called ammonotelic.	The animals performing aminotelism are called aminotelic.
e.g. Prawns, bony fishes, molluses, etc.	e.g. Unio, Limnea, Asterias and Pentaceros, etc

Question 32.
Descending limb of Henle’s loop and Ascending limb of Henle’s loop
Answer:
Descending limb of Henle’s loop and ascending limb of Henle’s loop

Descending limb	Ascending limb
It is very thin.	It is thick.
Direction of fluid flow is downward.	Direction of fluid flow is upward.
Permeable to water.	Impermeable to water.

Question 33.
Obligatory and Facultative rabsorption of water
Answer:
Obligatory and Facultative rabsorption of water

Obligatory reabsorption	Facultative reabsorption
Here, the reabsorption of water is independent of plasma osnolarity/water balance. Water follows reabsorbed solutes primarily Na+ and glucose.	Here, the reabsorpflon of water depends on plasma osmolatily/water balance.
It occurs in proximal convoluted tubule.	It occurs in late DCT and collecting duct.
Water is reabsorbed iso-osmotically and independent of ADH.	No reabsorption occurs in absence of ADH.

Explain the Location of the Following

Question 34.
Renal columns of Bertini
Answer:
Renal Columns of Bertini The renal column of Bertini is a medullary extension of the renal cortex in between the renal pyramids.

Question 35.
Duct of Bellini
Answer:
Duct of Bellini The largest straight excretory ducts in the kidney medulla and papillae whose openings form the area cribrosa.

Question 36.
Macula densa
Answer:
Macula densa Macula densa is located near the vascular pole of the glomerulus.

Question 37.
Vasa recta
Answer:
Vasa recta It is situated in the kidneys parallel to or surrounding the loop of Henle.

Long Answer Type Questions

Question 1.
Give an account of the structure of the human kidney.
Answer:
Human excretory system consists of a pair of kidneys,a pair of ureters, a urinary bladder and urethra, these are described below in detail

Human excretory system

Kidneys:
These are reddish brown, bean-shaped structures situated between the levels of last thoracic and third lumbar vertebra. These are close to the dorsal inner wall of the abdominal cavity.
Each kidney of an adult human measures, 10-12 cm in length, 5-7 cm in width, 2-3 cm in thickness with an average weight of 120-170 gm (i.e., 150 gm in males and about 135 gm in females).
Kidneys are mesodermal in origin. They develop from mesodermal nephrostomes or mesomeres, i.e. ciliated structures, functional in embryonic conditions.

Position of Kidneys:
The kidneys are located below the diaphragm on the left and right sides. The right kidney is lower and smaller than the left kidney because the liver takes up much space of the right side.

Structure of Kidney:
Structure of kidney can be studied well under two heads, i.e., external as well as internal structure.These are described below as

External Structure:
The outer surface of each kidney is convex. Inne/ concave surface has a notch called hilum. The supply of blood occurs through hilum. If we look from outside to inside, three layers cover the kidneys. These include renal fascia (outermost), the adipose layer and then renal capsule (innermost layer).
These coverings protect the kidneys from external shocks and injuries.

Internal Structure:
The LS of a mammalian kidney shows differentiation into outer cortex and inner medulla.

LS of kidney

Inside the kidney, the ureter is expanded as a funnel-shaped cavity called pelvis. The free end of pelvis has number of cup-like cavities called major calyces (sing, calyx) and minor calyces.

Medulla projects into the calyces as conical processes, called renal pyramids or medullary pyramids. The tip of pyramids are called renal papillae. The cortex spreads in between medullary pyramids as renal columns called columns of Bertini.

Microscopic Structure:
Each kidney is composed of numerous (nearly one million) complex tubular structures called nephrons. These are the functional units of kidney.

Functions of Kidney:
Following functions are served by kidney
(i) Regulation of water and electrolyte balance.
(ii) Regulation of arterial pressure.
(iii) Excretion of metabolic waste and foreign chemicals.
(iv) Secretion of hormones like renin, erythropoietin, etc.

Question 2.
Give an account of the structure and functions of the human kidney.
Answer:
Human excretory system consists of a pair of kidneys,a pair of ureters, a urinary bladder and urethra, these are described below in detail

Human excretory system

Kidneys:
These are reddish brown, bean-shaped structures situated between the levels of last thoracic and third lumbar vertebra. These are close to the dorsal inner wall of the abdominal cavity.
Each kidney of an adult human measures, 10-12 cm in length, 5-7 cm in width, 2-3 cm in thickness with an average weight of 120-170 gm (i.e., 150 gm in males and about 135 gm in females).
Kidneys are mesodermal in origin. They develop from mesodermal nephrostomes or mesomeres, i.e. ciliated structures, functional in embryonic conditions.

Position of Kidneys:
The kidneys are located below the diaphragm on the left and right sides. The right kidney is lower and smaller than the left kidney because the liver takes up much space of the right side.

Structure of Kidney:
Structure of kidney can be studied well under two heads, i.e., external as well as internal structure.These are described below as

External Structure:
The outer surface of each kidney is convex. Inne/ concave surface has a notch called hilum. The supply of blood occurs through hilum. If we look from outside to inside, three layers cover the kidneys. These include renal fascia (outermost), the adipose layer and then renal capsule (innermost layer).
These coverings protect the kidneys from external shocks and injuries.

Internal Structure:
The LS of a mammalian kidney shows differentiation into outer cortex and inner medulla.

LS of kidney

Inside the kidney, the ureter is expanded as a funnel-shaped cavity called pelvis. The free end of pelvis has number of cup-like cavities called major calyces (sing, calyx) and minor calyces.

Medulla projects into the calyces as conical processes, called renal pyramids or medullary pyramids. The tip of pyramids are called renal papillae. The cortex spreads in between medullary pyramids as renal columns called columns of Bertini.

Microscopic Structure:
Each kidney is composed of numerous (nearly one million) complex tubular structures called nephrons. These are the functional units of kidney.

Structure of Nephron or Uriniferous Tubule:
Each nephron consists of two parts, i.e., the Malpighian body or renal corpuscle and the renal tubule.
(i) Malpighian Body or Renal Corpuscle Glomerulus along with Bowman’s capsule is called the Malpighian body or renal corpuscle which filters out large solutes from the blood and delivers small solutes to the renal tubule for modification.

Malpighian body (renal corpuscle)

Glomerulus is a tuft of thin-walled capillaries formed by the branching of afferent arteriole (a fine branch of renal artery).
Bowman’s Capsule (Glomerular capsule) It is a double-walled, cup-like structure that surrounds the glomerulus. The outer parietal wall of glomerulus is composed of flattened (squamous) cells and the inner visceral wall is composed of a special type of less flattened cells, called podocytes.

Diagrammatic representation of a nephron

(ii) Renal Tubules
Attached to each Bowman’s capsule is a long, thin tubule with three distinct regions.
These regions are described as follows
(a) Proximal Convoluted Tubule (PCT) Behind the neck, it makes few coils and is restricted to the cortical region of the kidney.
(b) Henle’s Loop It is quite narrower and U-shaped (or hair pin-shaped) having a descending limb that ends into the medulla and an ascending limb that extends back from the medulla into the cortex.

Differences between descending limb and ascending limb of henle’s loop

Descending limb	Ascending limb
It is very thin.	It is thick.
Direction of fluid flow is downward.	Direction of fluid flow is upward.
Permeable to water.	Impermeable to water.

(c) Distal Convoluted Tubule (DCT) is thicker and highly, coiled structure situated in the cortex like the proximal tubule. Coils of both convoluted tubules are intermingled.
(d) Collecting Tubule The last part of nephron is called collecting or straight tubule, which is lined by cuboidal cells.

Collecting tubules of many nephrons open into a large collecting duct. Several adjacent collecting tubules converge to open into a short and thick duct of bellini. All ducts of Bellini, then open into the renal pelvis through medullary pyramids in the calyces.
Peritubular Capillary Network (PTCN) is formed when a minute vessel of peritubular capillaries run parallel to the loop of Henle forming a U-shaped vasa recta.
All these capillaries join to form renal venules, which join to form a renal vein that opens into the inferior vena cava.

Types of Nephrons:
Based on the location in the kidney, nephrons are of following two types
(i) Cortical Nephrons:
In majority of nephrons, the loop of Henle is too short and extends only very little into the medulla, i.e., lie in the renal cortex. Such nephrons are called cortical nephrons.

(ii) Juxtamedullary Nephrons:
In some of the nephrons, the loop of Henle is very long and runs deep into the medulla. These nephrons are called juxtamedullary nephrons.

Note The cortical nephron forms about 80% of the total nephron count while rest 20% are the juxtamedullary nephron

Blood Supply to the Nephron:
Blood to each kidney is supplied by a renal artery and is drained by the renal vein. Both these blood vessels pass through hilus. The renal artery after entering into kidney divide into afferent arterioles each afferent arteriol form a tuft of capillaries in glomerulus. The capillaries reunite to form the efferent arteriole.

The afferent arteriole is short and wide that supplies blood to the glomerulus, while, the efferent arteriole is narrow and long carrying blood away from the glomerulus.

Differences between afferent arteriole and efferent arteriole

Afferent arteriole	Efferent arteriole
These are the fine branches of renal artery which enter in each kidney and arise from dorsal aorta.	These are the fine branches of renal vein which leave the kidney and joins with inferior vena cava.
They bring arterial blood to the renal corpuscles.	They carry venous blood away from the renal corpuscles.
Its diameter is more.	Its diameter is comparatively less.
The blood flowing in it is rich in waste products.	The blood flowing in it is poor in waste products.

Functions of Kidney:
Following functions are served by kidney
(i) Regulation of water and electrolyte balance.
(ii) Regulation of arterial pressure.
(iii) Excretion of metabolic waste and foreign chemicals.
(iv) Secretion of hormones like renin, erythropoietin, etc.

Question 3.
Give an account of the mechanism of urine formation.
Answer:
Formation of Urine:
The formation of urine is the result of processes like glomerular filtration, selective reabsorption and tubular secretion. These processes occur in different parts of nephrons. Details of these are as follows

Ultrafiltration or Glomerular Filtration:
The first step of urine formation is the filtration of blood. It is carried out by the glomerulus. That is why this step is called glomerular filtration.
Kidneys filter about 1100-1200 mL of blood per minute, which constitute roughly 1/5th of the blood pumped out by each ventricle of the heart in a minute.
The glomerular capillary blood pressure causes filtration of blood through three layers, i.e.,
(i) the endothelium of glomerular blood vessels.
(ii) the epithelium of Bowman’s capsule.
(iii) a basement membrane (present between the above mentioned two layers).
The podocytes (epithelial cells of Bowman’s capsule) are arranged in such a manner, so that some minute spaces called filtration slits or slit pores occur between them.

Diagram representing the path taken by fluid (glomerular filtrate) during its passage from the plasma in a glomerular capillary of the lumen of a renal capsule

On account of the high pressure in the glomerular capillaries, the substances are filtered through these pores into the lumen of the Bowman’s capsule (but the RBC, WBC and plasma proteins having high molecular weight unable to pass out).

Varying pressures that operates between glomerular capillary and the Bowman’s capsule.

That’s why this process of filtration through glomerular capillaries in the Bowman’s capsule is known as ultra filtration and the filtrate is called glomerular filtrate.

It is hypotonic to urine that is actually excreted. Basic function of nephron is to clear out the plasma from unwanted substrates and also maintain the osmotic concentration of the blood plasma. Thus, the fluid coming out is known as urine, whose formation occurs inside the kidney.

Glomerular Filtration Rate:
The amount of the filtrate formed by the kidneys per minute is called Glomerular Filtration Rate (GFR). In a healthy person it was found approximately 125 mL /min, i. e., 180 L/day. GFR is regulated by one of the efficient mechanism carried out by Juxtaglomerular Apparatus (JGA).

JGA is a special sensitive region formed by cellular modifications in the distal convoluted tubule and the afferent arteriole at the location of their contact.
This apparatus includes
(i) granular juxtaglomerular cells in the afferent arteriole.
(ii) macula densa cells of DCT.
(iii) agranular lacis cells situated in between the above two.

Question 4.
Give an account of the role of the human kidneys in osmoregulation.
Answer:
Osmoregulation refers to the control of water level in the body. When there is excess of water in the body, kidney produces large volume of dilute urine and brings the water level to correct position. In the event of deficiency of water, kidney helps to conserve body water by producing small.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 18 Body Fluids and Circulation Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 18 Question Answer Body Fluids and Circulation

Body Fluids and Circulation Class 11 Questions and Answers CHSE Odisha

Very Short Answer Types Questions

Objective Type Questions

Question 1.
Double circulation is exhibited by
(a) Rohu
(b) Cockroach
(c) Scoliodon
(d) Frog
Answer:
(d) Frog

Question 2.
Which of the following is not a granulocyte?
(a) Neutrophil
(b) Monocyte
(c) Eosinophil
(d) Basophil
Answer:
(b) Monocyte

Question 3.
Serum does not contain
(a) fibrin
(b) albumin
(c) globulin
(d) bilirubin
Answer:
(a) fibrin

Question 4.
Drumstick, representing sex chromatin is present in
(a) eosinophil
(b) neutrophil
(c) lymphocyte
(d) monocyte
Answer:
(b) neutrophil

Question 5.
Adult haemoglobin (HbA) contains
(a) Gamma globin chains
(b) Beta globin chains
(c) Epsilon globin chains
(d) Zeta globin chains
Answer:
(b) Beta globin chains

Question 6.
An amino acid substitution in the beta globin chain causes
(a) Haemolytic anemia
(b) Pernicious anemia
(c) Microcytic anemia
(d) Sickle-cell anemia
Answer:
(b) Pernicious anemia

Question 7.
The presence of a large number of immature leucocytes in the circulation is indicative of
(a) leucocytosis
(b) leukemia
(c) leucopenia
(d) leucomorphosis
Answer:
(a) leucocytosis

Question 8.
Find the incorrect pair.
(a) Neutrophil – Phagocyte
(b) Eosinophil – Histamine
(c) Lymphocyte – Immunoglobulin
(d) Monocyte – Macrophage
Answer:
(b) Eosinophil – Histamine

Question 9.
Open circulation is exhibited by
(a) annelids
(b) vertebrates
(c) arthropods
(d) protectorates
Answer:
(c) arthropods

Question 10.
Myogenic heart is present in:
(a) annelids
(b) molluscs
(c) arthropods
(d) vertebrates
Answer:
(d) vertebrates

Question 11.
An instrument that measures the blood pressure is known as
(a) Haemometer
(b) Haemocytometer
(c) Sphygnomanometer
(d) Haemoglobinometer
Answer:
(c) Sphygnomanometer

Question 12.
Pacemaker is synonymous with
(a) SA Node
(b) Bundle of His
(c) AV Node
(d) Purkinje fibers
Answer:
(a) SA Node

Question 13.
Find out the correct route of blood circulation
(a) Venacava → Left atrium → Left ventricle → Pulmonary artery → Lung → Pulmonary vein → Right atrium → Right ventricle → Aorta
(b) Venacava → Right atrium → Right ventricle → Pulmonary artery → Lung → Pulmonary vein → Left atrium → Left ventricle → Aorta
(c) Venacava → Left atrium → Left ventricle → Pulmonary vein → Lung → Pulmonary artery → Right atrium → Right ventricle → Aorta
(d) Venacava → Left atrium → Right ventricle → Pulmonary artery → Lung → Pulmonary Vein → Left atrium → Right ventricle → Aorta
Answer:
(b) Venacava → Right atrium → Right ventricle → Pulmonary artery → Lung → Pulmonary vein → Left atrium → Left ventricle → Aorta

Question 14.
Find the incorrect match:
(a) Blood group A – Antigen A on red cell and anti-B antibody in the serum
(b) Blood group B – Antigen B on red cell and anti-A antibody in the serum
(c) Blood group AB – Antigen B on red cell and anti-A antibody in the serum
(d) Blood group O – No antigen A or B on the red cell and both anti-A and anti- B in the serum
Answer:
(c) Blood group AB – Antigen B on red cell and anti-A antibody in the serum

Question 15.
The fourth heart sound is produced by
(a) Closure of the aortic and pulmonary valves
(b) Closure of the bicuspid and tricuspid valves
(c) Vibration in the ventricular wall during systole
(d) Rapid ventricular filling
Answer:
(d) Rapid ventricular filling

Question 16.
Why of the following is not a part of the intrinsic blood coagulation pathway?
(a) Tissue thromboplastin
(b) Prothrombin
(c) Fibrinogen
(d) Ca²⁺
Answer:
(a) Tissue thromboplastin

Question 17.
Thalasemia is characterised by
(a) Globin chains are abnormal in haemoglobin
(b) The structure of heme is altered in haemoglobin
(c) Decreased synthesis of normal globin chains in haemoglobin
(d) Complete absence of globin chains in haemoglobin
Answer:
(c) Decreased synthesis of normal globin chains in haemoglobin

Question 18.
Complete (third degree) heart block is due to
(a) Ventricular fibrillation
(b) The conduct from the atria to the ventricles is completely interrupted
(c) The conduct from the atria to the ventricles is partially blocked or slowed
(d) One branch of the bundle of His is inhibited
Answer:
(a) Ventricular fibrillation

Answer the Following in One Word

Question 1.
The blood filled space and the blood in cockroach.
Answer:
Haemocoel and Haemolymph

Question 2.
The number of pulsatile chambers in the heart of cockroach.
Answer:
13

Question 3.
The heart of cyclostomes and fishes through which deoxygenated blood always circulates.
Answer:
Venous heart

Question 4.
The percentage of erythrocytes in the total volume of human blood.
Answer:
45%

Question 5.
Swelling and disintegration of erythrocytes in a hypotonic solution.
Answer:
Haemolysis

Question 6.
Shrinking of erythrocytes in a hypertonic solution.
Answer:
Crenation

Question 7.
Iron is transported in conjugation with a protein carrier in the blood.
Answer:
Transferrin

Question 8.
Higher number of erythrocytes than normal in the blood.
Answer:
Polycythemia

Question 9.
Abnormally lower haemoglobin percentage in the blood.
Answer:
Anemia

Question 10.
Lack of ankyrin in the cytoskeleton of erythrocytes causes a hereditary disorder.
Answer:
Spherocytosis

Question 11.
An amino acid substitution in the p-globin chain of the haemoglobin causes a hereditary disorder
Answer:
Sickle- cell anemia

Question 12.
Expression of abnormal polypeptides in the haemoglobin by mutant genes gives rise to a pathological condition.
Answer:
Haemoglobinopathies

Question 13.
Decreased synthesis of normal a and P globin chain gives rise to a pathological condition.
Answer:
Thalasemia

Question 14.
Trans membrane migration of leucocytes into the tissues from the blood vessels.
Answer:
Diapedesis

Question 15.
The site of maturation of lymphocytes into B-lymphocytes takes place in an organ of bird.
Answer:
Thymus

Question 16.
An enzyme from the damaged tissue that activates prothrombin into thrombin.
Answer:
Protease

Question 17.
An abnormally higher number of thrombocytes in the blood.
Answer:
Thrombocytosis

Question 18.
An abnormally lower number of thrombocytes in the blood.
Answer:
Thrombocytopenia

Question 19.
The process of formation of erythrocytes in the bone marrow.
Answer:
Erythropoiesis

Question 20.
The cytokine, thrombopoietin stimulates a large multinucleate cell to from a large number of platelets.
Answer:
Megakaryocytes

Question 21.
The inter atrial connection in the embryonic heart of human.
Answer:
Foramen ovale

Question 22.
The footprint of embryonic inter-atrial connection in the inter-atrial septum of adult.
Answer:
Fossa ovalis

Question 23.
A vascular connection between the pulmonary trunk and the aorta in the embryonic heart of human.
Answer:
Ductus arteriosus

Question 24.
The outer squamous epithelium layer of the heart.
Answer:
Pericardium

Question 25.
The innermost squamous epithelium layer of the heart.
Answer:
Endocardium

Question 26.
The tendionous threads attaching the atrio -ventricular valves with the papillary muscles.
Answer:
Chordae tendineae

Question 27.
The blood pressure is measured by an instrument.
Answer:
Sphygmomanometer

Question 28.
The sound detected by the stethoscope in measuring the blood pressure.
Answer:
Sound of korotkoff

Question 29.
A protein that activates inactive plasminogen into active plasmin.
Answer:
Kallikrenin

Question 30.
The clinical condition, in which the conceived Rh⁺ antibody preparation injected into the Rh^– mothe dies.
Answer:
Erythroblastosis fetalis

Question 31.
The trade name of the anti Rh antibody preparation injected into the Rh^– mother.
Answer:
RhoGAM

Question 32.
The hardening and constriction of large and medium sized arteries due to the deposition of metabolic byproducts on the endothelium.
Answer:
Arteriosclerosis

Question 33.
The constriction of the lumen of large and medium sized arteries due to deposition of lipids or their derivatives on the endothelium.
Answer:
Artherosclerosis

Question 34.
The unbearable pain in the heart due to formation of an excess of lactate in the cardiac muscle due to prologed ischemia (lack of oxygen).
Answer:
Angina pectoris

Question 35.
An irreversible injury followed by death to the myocardial cells due to prolonged ischemia.
Answer:
Myocardial infarction

Question 36.
The drug that prevents atherosclerosis by inhibiting an enzyme in the cholesterol biosynthetic pathway in the liver.
Answer:
Statins

Question 37.
The radiograph that detects blockages in the coronary artery.
Answer:
Angiogram

Question 38.
The technique of clearing the blockages in the coronary artery.
Answer:
Angioplasty

Question 39.
A cylindrical support attached to the artery to prevent its narrowing down subsequently.
Answer:
Stent

Question 40.
Abnormal patterns of electrical conduction in the heart causes abnormal beating.
Answer:
Arrhythmias

Question 40.
A cardiac rate slower than 60 beats/min.
Answer:
Bradycardia

Question 41.
A cardiac rate faster than 100 beats/ min.
Answer:
Tachycardia

Question 42.
The coordinate contraction of myocardial cells at a rate of 200-300/ min.
Answer:
Systole

Question 43.
The contraction of different groups of myocardial cells at different times.
Answer:
Diastole

Question 44.
Ventricular fibrillation leads to complete cessation of blood supply to the brain and hence it’s functioning.
Answer:
Stroke

Fill in the Blanks

Question 1.
Blood circulation in human was discovered by …………….. .
Answer:
William Harvey

Question 2.
There are 13 pulsatile chambers in the heart of cockroach. Each chamber opens by apertures, known as …………….. .
Answer:
Sinuses

Question 3.
Two perforated diaphragms divide the haemocoel of cockroach into three sinuses, namely and …………….. , …………….. and …………….. .
Answer:
pericardial, perivisceral and perineural

Question 4.
………….. muscles, attached to the dorsal diaphragm regulate the contraction and relaxation of the heart in cockroach.
Answer:
Muscles

Question 5.
In double circulation, there are two circuits. One is pulmonary and the other is ………….. .
Answer:
Systemic

Question 6.
The average longevity of human erythrocytes is ………….. days.
Answer:
120

Question 7.
Human erythrocytes, often, pile up on their lateral sides forming a ………….. .
Answer:
rouleaux

Question 8.
The respiratory pigment in human blood is known as ………….. .
Answer:
haemoglobin

Question 9.
Haemoglobin is a conjugate protein consisting of a protein part ……….. conjugated to a non-protein part ………….. .
Answer:
Globin, haeme

Question 10.
In fetal haemoglobin (HbF), the beta- globin chains are substituted by ………….. globin chains.
Answer:
gamma

Question 11.
Deficiency of vitamin-B₁₂ causes ………….. anemia.
Answer:
Pernicious

Question 12.
Small size of erythrocytes and hence reduced haemoglobin content causes ………….. anemia.
Answer:
microcytic

Question 13.
Excessive destruction of erythrocytes causes ………….. anemia.
Answer:
aplastic

Question 14.
Four oxygen molecules bind to a molecule of haemoglobin one after another forming oxyhaemoglobin. This type of binding is known as cooperative or ………….. binding.
Answer:
allosteric

Question 15.
Erythropoiesis is stimulated by a hormone called ………….. which is secreted by ………….. .
Answer:
Erythropoietin , kidney

Question 16.
Increases in the number of leucocytes above normal is known as ………….. .
Answer:
leucocytosis

Question 17.
Decrease in the number of leucocytes below normal is known as ………….. .
Answer:
leucopenia

Question 18.
Neutrophils turn into ………….. at the site of microbial infection.
Answer:
phagocytes

Question 19.
Infection by helminth larvae causes a proliferation of a class of leucocytes, called ………….. .
Answer:
lymphocytes

Question 20.
………….. and mast cells release at the site of infection, which causes inflammation.
Answer:
Basophil, histamine

Question 21.
………….. infilter through the wall of the blood vessels into the tissues and turn into macrophages.
Answer:
Monocytes

Question 22.
The heart is surrounded by a double-walled membrane, known as ………….. .
Answer:
pericardium

Question 23.
External furrows, marking the internal divisions of the heart are known as ………….. .
Answer:
sulci

Question 24.
The wall of the heart consists of three layers, such as epicardium, myocardium and …………..
Answer:
endocardium

Question 25.
The venacava open into ………….. of the heart.
Answer:
right atrium

Question 26.
Semilunar valves guard the openings of ………….. and ………….. trunks.
Answer:
Aorta, pulmonary

Question 27.
Haemolysis of red cells results in the formation of ruptured plasma, membranes, known as ………….. .
Answer:
red cell ghosts

Question 28.
Crenation results in the formation of shrunken erythrocytes called ………….. .
Answer:
echinocytes

Question 29.
The left atrio- ventricular aperture is guarded by a ………….. or ………….. valve.
Answer:
bicuspid, mitral

Question 30.
Muscular bundles, projecting into the cavities of the ventricles constitute ………….. .
Answer:
papillary muscles

Question 31.
The heart itself is supplied by ………….. arteries.
Answer:
Coronary artery

Question 32.
Persons with ………….. are treated with digitalis.
Answer:
heart attack

Question 33.
Numerical expression of normal blood pressure of human is ………….. .
Answer:
120/80 mm Hg

Question 34.
………….. discovered the ABO blood grouping system.
Answer:
Karl Landsteiner

Question 35.
The AB blood group was discovered by ………….. and ………….. .
Answer:
Sturli, Decastallo

Question 36.
The Rh blood grouping was discovered by ………….. .
Answer:
Alexander S Wiener

Question 37.
Persons with ………….. blood group are known as universal donors.
Answer:
O

Question 38.
Persons with ………….. blood group are known as universal recipients.
Answer:
AB

Question 39.
The process of forming a clot in the wall of a damaged blood vessel and preventing blood loss is known as ………….. .
Answer:
blood clotting

Question 40.
The endothelial cells secrete ………….. and ………….. which act as vasodilators and inhibit platelet aggregation.
Answer:
Nitric oxide, Prostacyclin

Question 41.
The intrinsic pathway of blood clotting is initiated by the exposure of the plasma to negatively charged ………….. at the site of blood vessel damage.
Answer:
collagen

Question 42.
Extrinsic pathway of blood coagulation is initated by the releases of a tissue enzyme, at ………….. the site of tissue damage.
Answer:
Thromboplastin

Question 43.
The enzyme ………….. lyses fibrin mesh.
Answer:
plasmin

Question 44.
Streptokinase, a bacterial enzyme activates ………….. into ………….. .
Answer:
plasminogen , plasmin

Question 45.
Heparin, an anticoagulant activates ………….. .
Answer:
allergic reaction

Question 46.
Haemophilia A, an X- Linked recessive disorder, is caused due to the deficiency of a sub- unit of the blood coagulation factor ………….. the deficiency in another sub-unit of the same factor cause ………….. disease.
Answer:
Vm, von willebrand

Question 47.
Deficiency in the blood coagulation factor IX causes the disease ………….. .
Answer:
haemophilia B

Question 48.
Defective low density lipoprotein (LDL) receptors on the hepatocyte surface cause an inherited disease, known as ………….. .
Answer:
Artherosclerosis

Matching Type Questions

Question 1.
Match the following

Group A	Group B
1. Venacava and coronary sinus	(a) Left atrio-ventricular aperture
2. Aortic trunk	(b) Right atrium
3. Pulmonary veins	(c) Left ventricle
4. Pulmonary trunk	(d) Right atrio-ventricular aperture
5. Tricuspid valve	(e) Right ventricle
6. Bicuspid (Mitral) valve	(f) Left atrium

Answer:

Group A	Group B
1. Venacava and coronary sinus	(b) Right atrium
2. Aortic trunk	(c) Left ventricle
3. Pulmonary veins	(f) Left atrium
4. Pulmonary trunk	(e) Right ventricle
5. Tricuspid valve	(d) Right atrio-ventricular aperture
6. Bicuspid (Mitral) valve	(a) Left atrio-ventricular aperture

Question 2.
Match the following

Group A	Group B
1. End diastolic volume	(a) The volume of blood that remains in the ventricles following ventricular systole.
2. Isovolumetric contraction	(b) the volume of blood ejected following ventricular systole.
3. Stroke volume	(c) The ventricles relax as closed cavities.
4. End systolic volume	(d) The ventricles contract as closed cavities
5. Isovolumetric relaxation	(e) The volume of blood in the ventricles at the end of ventricular diastole.

Answer:

Group A	Group B
1. End diastolic volume	(e) The volume of blood in the ventricles at the end of ventricular diastole.
2. Isovolumetric contraction	(d) The ventricles contract as closed cavities
3. Stroke volume	(b) the volume of blood ejected following ventricular systole.
4. End systolic volume	(a) The volume of blood that remains in the ventricles following ventricular systole.
5. Isovolumetric relaxation	(c) The ventricles relax as closed cavities.

Question 3.
Match the following

Group A	Group B
1. Baroreceptor reflex	(a) Excretion of more water and sodium
2. Antidiuretic hormone	(b) Atrial wall
3. Atrial stretch reflex	(c) Regulates blood pressure by vasoconstriction
4. Aldosterone	(d) Aortic arch and carotid sinus
5. Renin- Angiotensin	(e) Reabsorption of salt and water by the kidneys
6. Atrial Natriuretic peptide	(f) Reabsorption of water by the kidneys.

Answer:

Group A	Group B
1. Baroreceptor reflex	(d) Aortic arch and carotid sinus
2. Antidiuretic hormone	(f) Reabsorption of water by the kidneys.
3. Atrial stretch reflex	(b) Atrial wall
4. Aldosterone	(e) Reabsorption of salt and water by the kidneys
5. Renin- Angiotensin	(a) Excretion of more water and sodium
6. Atrial Natriuretic peptide	(c) Regulates blood pressure by vasoconstriction

Short Answer Type Questions

Question 1.
Explain about the transport function of blood.
Answer:
Blood transports nutrients from alimentary canal to all the cells and tissue. This help in proper functioning and metabolic activities of body’s organs. Blood also transports respiratory gases such as O₂ and CO₂ from outside to the body and vice versa. It also helps in collection of excretory wastes from all parts of the body to the site of their elimination from the body.

Question 2.
What is open circulation ? Give an example.
Answer:
An open circulatory system is where the blood and interstitial fluid are allowed to mix in an organism.
Such organism don’t have true blood and the circulating fluid is referred to as haemolymph.
Organism with open circulatory system are arthropods and molluscs.

Question 3.
Why is the heart of cyclostomes and fishes called venous heart?
Answer:
The heart of cyclostomes and fishes is two chambered consisting an atria and a ventricle. Deoxygenated blood circulates through veins to gills for oxygenation and transported to all parts except heart. It is again collected by veins and emptied into the heart. The heart, thus contains only deoxygenated blood and known as venous heart.

Question 4.
What is systemic circulation?
Answer:
Systemic Circulation In this system, the pure blood is supplied to all parts of the body. During transport, the oxygenated (pure) blood entering the aorta is carried by a network of arteries, arterioles and capillaries to the tissues from where the deoxygenated (impure) blood is collected by a system of venules, veins and vena cava, thus, emptying it into the right atrium.

Question 5.
What is hematocrit?
Answer:
Haematocrit is the ratio of the volume of red blood cells to the total volume of blood. The erythrocytes constitutes approx 45% in men and 42% (women) to the total blood volume.

Question 6.
Why is the colour of the plasma straw yellow?
Answer:
It is a straw coloured, viscous, slightly alkaline aqueous body fluid. It forms about 55% of the blood. It’s straw colour is due to the presence of bilirubin and carotene.

Question 7.
What is a rouleauax? Where it is found?
Answer:
The rouleaux is the stacking of red blood cells one above the other when they are suspended in a suitable medium. It is seen when ESR is increased and plasma protein concentration is increased. It is caused by an increase in cathodal proteins like immunoglobulins and fibrinogen. The flat surface of the discoid RBCs give them a large surface area to make contact and stick with each other, thus forming a rouleauax.

Question 8.
What do you mean by haemolysis ?
Answer:
Haemolysis is the breakdown or destruction of red blood cells releasing the oxygen carrying pigment haemoglobin, into the surrounding medium. It is also a means of removing mature and dead RBCs from the bloodstream.

Question 9.
What is an echinocyte ?
Answer:
Echinocyte is a reversible condition of red blood cells. It is a form of RBC which has an abnormal cell membrane characterised by many small, evenly spaced thorny projections. It is seen when erythrocytes are placed in a hypertonic solution which leads to cell shrinkage. The phenomenon is called crenation and shrunken erythrocytes are called echinocytes.

Question 10.
What is haemoglobin A ?
Answer:
Haemoglobin A is called adult haemoglobin. It is made up of two β chains and two pairs of a chains (α₂β₂). Its the most common normal adult haemogloben (HbA); comprising over 97% of total RBC haemoglobin.

Question 11.
What is fetal haemoglobin?
Answer:
Fetal haemoglobin is the major haemoglobin present during gestation. It is completely replaced by adult haemoglobin by approx 6-12 months of age.
In fetal hb, the β globin chains are substituted by gamma(γ) chains. It has very high affinity towards oxygen and is more efficient than adult haemoglobin.

Question 12.
Explain about allosteric binding of oxygen to haemoglobin.
Answer:
Haemoglobin:
Haemoglobin is a conjugate protein consisting of a protein part globin conjugated to a non-protein part called haeme.
The globin consists of a and b polypeptides, two each.
The heme consist of four sub-units, each containing a porphyrin or tetra-pyrrole ring. At the centre of porphyrin, Fez+ is present which impart red colour to haemoglobin.

The Fe²⁺ is attached by four coordinate bonds to the four pyrrole rings and by two more coordinate bonds to the globin (α or β) chain. One of the coordinate bonds, by which it is attached to the globin chain is displaced by molecular oxygen and consequently, oxyhaemoglobin is formed. Due to its oxygen carrying function haemoglobin is known as a respiratory pigment. The haemoglobin containing two each of a and b globin chains is termed as adult haemoglobin (haemoglobin A).

The b globin chain in 25% of adult haemoglobin is substituted by d globin chain. In foetus, however, the b globin chains are substituted by g chains. This haemoglobin has been referred to as fetal haemoglobin (haemoglobin F).

Question 13.
What is sickle cell anemia? How does it differ from haemolytic anemia?
Answer:
Sickle Cell Anemia: The haemoglobin is abnormal due to an amino acid substitution in the b-globin chain. The erythrocytes remain sickle-shaped and the haemoglobin has a reduced oxygen carrying capacity. It is an autosomal recessive disorder.

Question 14.
Explain about leucopenia.
Answer:
The normal count of white blood cells is 5000-10,000 per cubic millimeter. When this count drops below 3500 per cubic millimeter in the blood indicates leucopenia.
The decrease in the number of leucocytes below the normal count is called leucopenia.

Question 15.
What is thalasemia ?
Answer:
Thalassemia: An autosomal recessive disease, occurring due to mutation or deletion of genes. Polypeptides are normal, there is decreased synthesis of α or β-globin accordingly the disorder is either α-thalassemia or β-thalasemia.

Question 16.
What is diapedesis?
Answer:
These are known to be the most active and motile constituent of blood as well as lymph. They do not possess the red colour pigment (haemoglobin) in them, so they are colourless in nature.
These are nucleated and are generally short lived cells. The number of WBCs are relatively lesser in number, about 6000-8000 mm³ of blood. They move in an amoeboid fashion.
These can squeeze through capillary wall and move to the site of action. This phenomenon is called diapedesis.

Question 17.
A basophil is functionally related to an areolar connective tissue cell. Name the cell and explain the function.
Answer:
Basophils are functionally related to mast cells. Mast cells are areolar tissues which releases granules and chemicals histamine, cytokinin, heparin and many proteases in the surrounding environment. They are chemical mediators causing inflammatory and allergic reactions.

Question 18.
Ennumerate the types of granulocytes and their individual functions.
Answer:
Agranulocytes They lack granules in their cytoplasm and have rounded or oval nucleus. Agranulocytes are also further subdivided into two main types
1. Lymphocytes These are smaller in size and have rounded indented nucleus. Lymphocytes are of further two types, i.e. B-cells and T-cells. Both of these (i.e. B and T-cells) are responsible for immune responses of the body.
2. Monocytes These are largest of all types of WBCs, but are fewer in number. Their nucleus is horse-shoe shaped. Mature monocytes are known as macrophages. They help to kill foreign particles. These are phagocytic in nature.
Img 1

Question 19.
Mention the two major functions of lymphocytes.
Answer:
Lymhyphocytes play an important role in the immune response generated by the body.

• The T-lymphocytes acts as killer cells which help in elimination of pathogenic microorganisms entering the host body.
• B-Cells / lymphocytes secretes antibody and memory cells.

Question 20.
What is hematopoiesis? Where does it occur?
Answer:
Haematopoises or haemopoiesis is the process of formation of blood cells. This process occurs in liver of the foetus when undifferentiated stem cells migrate from yolk sac to liver. After birth, liver stop the function of haematopoietic organ and bone marrow take up this function till death.

Question 21.
Why the human heart is myogenic?
Answer:
Myogenic Heart: In myogenic heart nerve stimulation is not required to initiate heartbeat and few localised cardiac muscles perform this function intrinsically. Node is the collection of specialised cardiac muscle cells, e.g. sino-atrial node (SA).

Question 22.
What is fossa ovalis ?
Answer:
The two atrium of human heart are separated from each other by a complete partition called the inter-atrial septum. Fossa ovalis is an oval shaped depression present just above the inferior vena cava orifice in intra-atrial septum in right atrium.

Question 23.
Why are atrio-ventricular valves called cuspid valves?
Answer:
The atrio ventricular valves i.e the mitral and tricuspid valves are present (bicuspid) between the upper chambers (atria) and lower chambers (ventricles).
These are so named because of the cusps or leaflet-like covering (three on tricuspid and two on bicuspid) on them.

Question 24.
What do you mean by action potential?
Answer:
The action potential is a transient depolarisation of the membranes of specialised myo cardial cells present in the S.A node.

Question 25.
For a moment (0.4 sec), the entire heart is in diastole-explain.
Answer:
The diastole (phase of relaxation) of the atria and ventricles always partly overlaps. Hence, both the atrial and ventricle chambers Eire in a diastole together for period of 0.4 seconds.

Question 26.
What do lubb and dupp signify?
Answer:

1. LuBB: It is the first sound, being produced when inter auriculoventricular valves (tricuspid and bicuspid valve) are closed. This marks the end of the atrial systole and beginning of ventricular systole.
2. DuPP: It is the second sound being produced when semilunar valves (of aorta and pulmonary artery) get closed. This marks the end of ventricular systole.

Question 27.
The standard notation of blood pressure (120/ 80 mm Hg) refer to systolic and diastolic pressures of the systemic circulation-Explain.
Answer:
The pressure exerted by the blood on the walls of blood vessels is called as blood pressure, Systolic blood pressure (contraction of ventricles) measures the pressure exerted on the artery wall during heart beats. This pressure rises to about 120 mm Hg.

Dieistolic blood pressure (ventricles relax and pressure in left ventricle falls below that of aorta) measures the pressure exerted by blood against artery walls when the heart is relaxing between beats. This pressure is measured to be 80 mm Hg. 120/80 mm Hg thus indicates the blood pressure of normal healthy individual.

Question 28.
How do antidiuretic hormone (ADH) regulate blood pressure?
Answer:
ADH or vassopressin is secreted by hypothalamus when there is excessive loss of fluid from the body or blood pressure is too low.
Osmotic sensors in the hypothalamus reacts to concentration of certain molecules like Na⁺,K⁺ Cl^– and CO₂. When their concentration is not balanced or blood pressure is too low, ADH is released. It has constrictory effect on blood vessels and thus increases the pressure by increasing the volume of water and blood in the body.

Question 29.
What is aldosterone? How it is related to the maintenance of blood pressure.
Answer:
Aldosterone is secreted by zona glomerulosa of adrenal gland which regulates water and electrolyte balance in the body.
If a decreased blood pressure is detected, the adrenal gland stimulates the stretch receptors to release aldosterone which inturn increases sodium reabsorption from the urine, sweat and the gut. This leads to increaseds molarity in the extracellular fluid which returnes the blood pressure towards normal.

Question 30.
What is ECG?
Answer:
ECG (Electrocardiogram) is a record of the electrical activity of heart. It shows the heart’s activity as line tracings on paper where the fluctuations; appearing are called waves.
An ECG graph includes deflections, i.e. P wave (atrial repolarisation) QRS wave (ventricular depolEirisation) and T wave (ventricular repolarization). Any deviation from normal ECG indicates abnormal functioning of heart.

Question 31.
What happens if there is a mismatched blood transfusion?
Answer:
It is always necessary to match the blood types prior to blood transfusion of both the donor and the recipient. If the types do not match a severe haemolytic reaction can occur in the recipient. This involves the the clumping or agglutination of blood cells and the red blood cells will be destroyed by recipients immune system.

Question 32.
What is haemolytic disease of the newborn ?
Answer:
This could be fatal to the developing foetus and could cause severe anaemia and jaundice to the developing baby. This is known as erythroblastosis foetalis or haemolytic disease of newborn.

Question 33.
What is platelet plug?
Answer:
When ever an injury occurs, the platelets come and stick together to the damaged endothelium forming a platelet plug. It temporarily seals the break in the vessel wall and blood clot formation occurs at the site.

Question 34.
What is platelet release reaction.?
Answer:
Plateletes forms a clot at the injury site. They release factors to stimulate further reactions. Plateletes adheres to collagen fibres in vessel wall by becoming adhesive and filamentous due to von willebrand factor. They degranulate releasing ADP, serotonin and throm boxane. This phenomenon is known as the platelet release reaction.

Question 35.
What is the function of streptokinase?
Answer:
Stretptokinase is a bacterial enzyme isolated from genetically modified Streptococcus.
It is used as clot buster for removing clots from the blood vessels of heart patients suffering from myocardial infarction. Streptokinase vaccinates plasminogen forming, plasmin.

Question 36.
What is EDTA? How does it help in blood preservation?
Answer:
EDTA is Ethylene Diamine tetra acetic Acid.
It is a chelating agent that binds calcium and other metals and also used as an anticoagulant for preserving blood samples.
It is added to sample collection tubes and bags to prevent blood cells from clumping and clotting together.

Question 37.
How does heparin act as an anticoagulant?
Answer:
Heparin is a natural anticoagulant. Inside an intact blood vessel the blood does not coagulate because of the presence of active anticoagulants like heparin.
It also activates antithrombin III a circulating plasma protein, which inactivates thrombin and other clotting factors.

Question 38.
What is arteriosclerosis?
Answer:
It is the hardening of arteries and arterioles due to the thickening of the fibres tissue and the consequent loss of elasticity. This mainly affects the vessels, which are mainly responsible for supplying blood to the heart muscle. It seems to occur due to deposition of calcium, fat cholesterol and fibrous tissues making the lumen of arteries narrower.
Img 2
(a) An artherosclerosis plaque in the arterial wall
(b) Cross seaction of a coronary artery showing an Artherosclerotic plaque and clot in lumen
512

Question 39.
What is the role of cholesterol in producing atherosclerosis?
Answer:
The cholesterol molecules conjugate with plasma proteins and articulate in blood as lipopoteins. They associate with endothelial cells triggering the synthesis of cell adhesion bimolecules specific for monocytes. The monocytes transforms into macrophages, engulfs the associated lipid and become foam cells. These together with more leucocytes form atherosclerotic plaques thus initiating the disease as the deposited lipids and macrophages calcifies.
Thus, the occurrence of atherosclerosis coincides with concentration of LDL (Low density lipoprotein) in blood.

Question 40.
What is angioplasty?
Answer:
Angioplasty is a procedure which involves opening of narrowed or blocked blood vessels (coronary arteries) that supply blood to the heart.
It restores normal blood to the heart by threading a catheter via a small puncture in arm or leg artery to the heart. Blocked artery opens when a tiny ballon is inflated in the catheter.

Question 41.
How does TPA help in dissolving a thrombus?
Answer:
TPA, tissue Plasminogen Activator is a protein found on endothelial cells involved in the breakdown of blood clots. It activates plasminogen to plasmin during clot formation. Human TPA is now a days also produced by recombinant- DNA technology.

Question 42.
What is bradycardia?
Answer:
Bradycardia is the term indicating a slow heart or pulse rate, i.e. under 50 beats/ minute. It also indicates a problem in heart’s electrical system.

Question 43.
What is lymph? How does it circulate?
Answer:
Lymph is a colourless fluid connective tissue with high concentration of specialised lymphocytes (WBC), floating in lymph vessels.
It circulates via an elaborate network of lymphatic vessels, which collects interstitial fluid along with some proteins and drains it back to major veins.

Write Brief Notes

Question 1.
Functions of blood
Answer:
Functions of blood Blood performs the following important functions .

• Helps in transportation of respiratory gases (i.e., O₂, CO₂, etc).
• Helps in healing of wounds.
• Maintains body pH, water and ionic balance.
• Fight against infections by forming body immunity.
• Also helps in transportation of hormones from endocrine glands to target organs.

Question 2.
Agranulocytes
Answer:
Agranulocytes They lack granules in their cytoplasm and have rounded or oval nucleus. Agranulocytes are also further subdivided into two main types
(a) Lymphocytes These are smaller in size and have rounded indented nucleus. Lymphocytes are of further two types, i.e. B-cells and T-cells. Both of these (i.e. B and T-cells) are responsible for immune responses of the body.
(b) Monocytes These are largest of all types of WBCs, but are fewer in number. Their nucleus is horse-shoe shaped. Mature monocytes are known as macrophages. They help to kill foreign particles. These are phagocytic in nature.
Img 1
Structure of agranulocytes, (a) Lymhyphocyts; and (b) Monocytes

Question 3.
Double circulation
Answer:
Double Circulation
The mammalian heart is four-chambered, undergoing the process of complete separate double circulation. This means that blood passes twice through the heart to supply the blood for once to the body. This transmission is necccssary, as it helps in oxygenation of blood.

The following processes constitute the double circulation
(i) Pulmonary Circulation In this system, blood completes its circulation from right ventricle to the left atria through the lungs. Here, the deoxygenated blood pumped by the right ventricle enters the pulmonary artery while, the left ventricle pumps blood into the aorta.
The deoxygenated blood is passed on to the lungs from where, the oxygenated blood is carried out by the pulmonary veins into the left atrium of heart.

(ii) Systemic Circulation In this system, the pure blood is supplied to all parts of the body. During transport, the oxygenated (pure) blood entering the aorta is carried by a network of arteries, arterioles and capillaries to the tissues from where the deoxygenated (impure) blood is collected by a system of venules, veins and vena cava, thus, emptying it into the right atrium.
This system provides essential nutrients, O₂ and other essential substances to all the tissues of body and eventually takes away CO₂ and other harmful substances away from tissues for their elimination from body.
Img 2
Plan of double circulation in a vertebrate

Question 4.
Haemoglobin
Answer:
Haemoglobin
Haemoglobin is a conjugate protein consisting of a protein part globin conjugated to a non-protein part called haeme.
The globin consists of a and b polypeptides, two each.
The heme consist of four sub-units, each containing a porphyrin or tetra-pyrrole ring. At the centre of porphyrin, Fe²⁺ is present which impart red colour to haemoglobin.

The Fe²⁺ is attached by four coordinate bonds to the four pyrrole rings and by two more coordinate bonds to the globin (α or β) chain. One of the coordinate bonds, by which it is attached to the globin chain is displaced by molecular oxygen and consequently, oxyhaemoglobin is formed. Due to its oxygen carrying function haemoglobin is known as a respiratory pigment.

The haemoglobin containing two each of a and b globin chains is termed as adult haemoglobin (haemoglobin A). The b globin chain in 25% of adult haemoglobin is substituted by d globin chain. In foetus, however, the b globin chains are substituted by g chains. This haemoglobin has been referred to as fetal haemoglobin (haemoglobin F).

Question 5.
Erythrocyte
Answer:
Erythrocyte Abnormality
(i) Polycythemia Increased number of erythrocytes.
(ii) Anemia Decreased number of erythrocytes. It is further of various types as follows

• Aplastic Anemia Destruction of bone marrow stem cells by chemicals, such as benzene, arsenic and radiation.
• Microcytic Anemia The erythrocytes remain smaller and hence, contain less haemoglobin than normal.
• Haemolytic Anemia Excessive destruction of erythrocytes.
• Pernicious Anemia Sub-normal absorption of vitamin-B₁₂ (cyanocobalamine) from the intestine due to a lack of intestinal protein, intrinsic factor, which assist in its absorption. Vitamin B12 helps in erythrocyte formation.

Question 6.
Anemia
Answer:
Anemia Decreased number of erythrocytes. It is further of various types as follows

• Aplastic Anemia Destruction of bone marrow stem cells by chemicals, such as benzene, arsenic and radiation.
• Microcytic Anemia The erythrocytes remain smaller and hence, contain less haemoglobin than normal.
• Haemolytic Anemia Excessive destruction of erythrocytes.
• Pernicious Anemia Sub-normal absorption of vitamin-B₁₂ (cyanocobalamine) from the intestine due to a lack of intestinal protein, intrinsic factor, which assist in its absorption. Vitamin B12 helps in erythrocyte formation.

Question 7.
Thalasemia
Answer:
Thalassemia An autosomal recessive disease, occurring due ro mutation or deletion of genes. Polypcptides are normal, there is decreased synthesis of α or ß-globin accordingly the disorder is either α-thalassemia or ß-thalasemia

Question 8.
Erythropoiesis
Answer:
Erythropoiesis The process whereby a fraction of primitive stem cells becomes committed towards the development of RBCs lineage. It involves specialised functional and structural differentiation. Approx 2.5 million RBCs are produced every second to replenish the dead cells in spleen and liver. The principle factor regulating erythropoiesis is hormone erythropoietin secreted by the kidneys.

Question 9.
Bone marrow transplantation
Answer:
These are the most abundant of all cells found in the blood. They are red in colour due to the presence of a pigment called haemoglobin, which acts as an oxygen carrier. The formation of RBCs take place in the red bone marrow in adults.

Shape, Size and Structure RBCs are biconcave, disc-shaped cells with the diameter of about 7-8 micron. The shape of RBC is slightly variable. As there are no cell organelles found in it, whole volume is filled with haemoglobin. A healthy individual has about 12-16 gm of haemoglobin in every 100 mL of blood.
When suspended in a suitable medium, erythrocytes pile up one above the other forming rouleaux.
Number In men, the average number of RBC is about 5-5.5 million per cubic millimeter (mm³) of blood.

In women, the average number is about 4-4.5. mm³ of blood.

Lifespan of RBC Total lifespan of RBC is 120 days. After which RBC becomes non-functional and gets destroyed in’spleen. Thus, spleen is also referred as the graveyard of RBCs.

Question 10.
Neurogenic heart
Answer:
Neurogenic Heart: In neurogenic heart muscle cells are incapable of initiating the heartbeat and a group of nerve cells (ganglion) are required to initiate the heart beat, e.g. arthropods and molluscs.

Question 11.
Pacemaker
Answer:
Pacemaker The sinoatrial node or SA node is the pacemaker of the heart. It is a small flattened patch of specialised tissue present in the right upper corner of the right atrium.

It generates electrical impulses (autoexcitable) which spreads in all directions of the heart i.e. it initiates contraction and relaxation of both auricles and ventricles. The sino-atrial node can generate maximum number of action potential, i.e. 70-75 mm, It is responsible for initiation and maintenance of the rhythmic contractile activity of the heart, hence also called as pacemaker of the heart.

Question 12.
Artificial pacemaker
Answer:
Artificial pacemaker When SA node fails to generate electrical impulses, the and heart can undergo serious consequences like cardiac arrest. In such cases, an artificial electrical stimulator called pacemaker, is introduced in the body to regulate the working of heart or generation of heart beats.

The artificial pacemaker is implanted under the skin, near the shoulders, connected with wires implanted in the heart. It regulates the impulses for number of heartbeats per minute.

Question 13.
Heart sounds
Answer:
During each cardiac cycle, two prominent sounds are produced which can be easily heard by a stethoscope (an instrument used for the amplification of sound). This allows to hear the sound and pulse of an individual. The basic reason for the production of these sounds is the closure of various valves. The sounds produced during each heartbeat are as follows

1. LuBB: It is the first sound, being produced when inter auriculoventricular valves (tricuspid and bicuspid valve) are closed. This marks the end of the atrial systole and beginning of ventricular systole.
2. DuPP: It is the second sound being produced when semilunar valves (of aorta and pulmonary artery) get closed. This marks the end of ventricular systole.

A Third (S3) and fourth (S4) sound also occur in normal individuals called gallops. S3 is associated with early diastolic felling, while S4 with late diastolic.

Question 14.
Cardiac output
Answer:
We have just studied that, our heart beats for about 72 times per minute (on an average). This concludes that in a single minute, many cardiac cycles are performed. Thus, deducing that duration of a each cardiac cycle is 0.8 s. During each cardiac cycle (i.e. in one beat) each ventricle pumps out about 70 mL of blood. This is known as stroke volume.

The volume of blood pumped out by each ventricle in one minute is called cardiac output. Thus, Cardiac output = Stroke volume X Numbers of beats /min.
The cardiac output is 5040 mL or appro × 5L in a normal individual.
It is to be noted that the body has the ability to alter stroke volume as well as the heart rate and thereby, the cardiac output. Athlete has much higher cardiac output than the normal man.

Question 15.
Electrocardiogram
Answer:
Electrocardiogram is a graphical representation of the electrical activity of the heart during a single cardiac cycle. It is obtained by a machine known as electrocardiograph.

Question 16.
Agglutination reaction
Answer:
Agglutination Reactions Agglutination reactions are visible expression of antigen-antibody interactions. For these reactions, a particular test antigen must be conjugated with a carrier (artificial like latex or biological like RBCs).

These conjugated antigens reacts with patient’s serum containing antibodies (if present). The result is observation of clumping due to antigen-antibody complex formation. Various agglutination tests are employed in diagnostic immunology like latex agglutination, direct bacterial agglutination, hemeagglutination, etc.

Question 17.
Anticoagulants
Answer:
Anticoagulants The substances that retards or inhibits the coagulation of the blood. Also known as blood thiners, these prolong the clotting time.

These can be naturally occurring like heparin and antiprothrombins which does not allow the blood to coagulate flowing inside the vessels.
Artificially occurring anticoagulant is EDTA (Ethylene Deimine Tetra Acetic Acid), a calcium chelating agent used in preservation of blood samples.

Anticoagulants inhibit the coagulation cascade by clotting factors that occurs after initial platelet aggregation.

Question 18.
Hemophilia
Answer:
Haemophilia It is a sex linked recessive disorder, the gene for which is present on X chromosome.
It is transmitted from an unaffected carrier female to some of the male offspring. The continues bleeding for long time than normal even due to a small affected individuals, injury because of defective blood coagulation.
Haemophilia is of two types
(i) Haemophilia A occurs due to deficiency of factor (VIII), a clotting protein (anti haemophilic factor) which in conjugate, active of factor (X) .
(ii) Haemophilia B occurs due to deficiency of factor (IX) (Plasma thromboplastin component )or Christmas factor.

Question 19.
Hypertension
Answer:
Hypertension: The pressure exerted by the flow of blood on the elastic walls of the arteries is known as blood pressure. Hypertension is the term used for blood pressure higher than the normal.

The normal blood pressure in humans is measured as 120/80 mmHg (millimetres of mercury pressure), in which 120 mmHg is the systolic pressure (pumping pressure), while, the 80 mmHg is the diastolic pressure (or resting pressure). ,
Persistent increase in blood pressure above 140 mmHg (systolic) and 90 mmHg (diastolic) is termed as hypertension.

Question 20.
Ischemic heart disease
Answer:
Ischemic Heart Disease Ischemic heart disease also known as coronary artery disease is a condition that affects the blood supply to the heart.
Mostly atherosclerosis leads to ischemic heart diseases wherein the blood vessels get narrowed or blocked due to deposition of cholesterol on their walls. This reduces oxygen and nutrient supply to the heart muscles; essential for normal functioning of heart. Eventually part of heart becomes dead often resulting in a heart attack. This also affects the oxygen supply to other vital organs like brain, liver and kidney, etc.

Question 21.
Atherosclerosis
Answer:
It is a disease where arteries get hardened due to deposition of calcium salts in their wall due to which calcium salts precipitate with cholesterol forming plaques. These plaques make the walls of the arteries hard. Healthy arteries are flexible, strong and elastic. In some cases, the hardened wall may crack making the internal wall rough.

This may lead to formation of thrombosis. Arteriosclerosis is an age related disease and may lead to increase in systolic blood pressure. Smoking and obesity are two major factors which may lead to arterioscloresis.

Question 22.
Congestive heart failure
Answer:
Congestive heart failure is a chronic progressive condition affecting the pumping action of heart muscles. It especially refers to the stage where fluid build up starts around the heart causing inefficient pumping of blood. Congestive heart failure develops when ventricles can’t pump blood in sufficient volume to meet the requirement of body due to weakening of its muscles. The main symptom of CHF is congestion of lungs.

Question 23.
Lymphatic system
Answer:
It is an elaborate network of lymph vessels lymph capillaries and lymph nodes, which collects the interstitial fluid (tissue fluid), along with some protein molecules and drains it back into the major veins.
The lymphatic vessels are present in all tissues (except the central nervous system and cornea).
Img 3
Structure of the lymphatic system in close association with the cardio-vascular system

Like blood capillaries, lymphatic vessels are lined by endothelium, but these are closed ended, i.e. these are not drained by vessels. Structurally, lymph vessels resembles the veins, i.e. they have three layers provided with valves at regular intervals to regulate unidirectional flow of lymph. Before draining into veins the lymph is filtered in lymph nodes. Lymph nodes contain lymphocytes.

Question 24.
Myocardial infarction
Answer:
Myocardial infarction is the irreversible death of (necrosis) of heart muscles due to prolonged lack of oxygen supply (ischemia) associated with blockage of coronary artery. These arteries supply oxygenated blood to heart muscles, without which the muscles supplied by blocked artery begins to infarct (die).

The most common causes of myocardial infarction is atherosclerosis, i.e. a accumulation of fatty plaque inside the artery. The damaged calls can not be repaired nor.be regenerated. MI is detected by the changing pattern of the S-T segment of the ECG. Also measuring the plasma concentrations of enzymes, creative phosphokinase (CPK) and lactate dehydrogenase ,(LDH) helps in diagnosis of MI.

Question 25.
Blood coagulation
Answer:
Blood coagulation When an injury occurs, it is stopped by a process called blood clotting or coagulation. It is the function of blood platelets and other factors present in blood. It occus in three steps.
1. Thromboplastin, help in formation of an enzyme prothrombinase (which inactivates heparin) that converts the inactive plasma protein, i.e. prothrombin into its active form thrombin.

2. Thrombin thus, acts as a proteolytic enzyme to convert fibrinogen molecule (produced from the liver in the presence of vitamin – K) to form insoluble fibrin monomer. This reaction requires thrombokinase.

3. These fibrin monomers polymerise to long, sticky fibres. The fibrin threads forms a fine network of threads called fibrins, in which dead and damaged formed elements of blood are trapped.
This finally leads to the formation of a clot or coagulum, which is a dark reddish brown scum formed over the surface of injury.

Question 26.
ABO blood groups
Answer:
It was reported by Karl Landsteiner. It is based on the presence or absence of antigen A or antigen B on the surface of RBCs.
People with blood group A have the antigen A on the surface of their RBCs and have antibodies against antigen B in their plasma. While in the people having blood group B, the case is just vice-versa.
Apart from both these blood groups (i.e. A and B) people with blood group AB have both antigen A and B on their RBCs surface and no antibodies for either of the antigens in their plasma.

In people with blood group O, both antigen A and B are not present on their RBCs, but they have both A and B antibodies against the plasma.
A, B and O blood groups were discovered by Landsteiner (1900). Blood group AB was discovered by de Castello and Steini (1902).

Differentiate between

Question 1.
Plasma and Serum
Answer:
Plasma and Serum

Plasma	Serum
Plasma is a straw yellow coloured fluid component of blood containing all types of organic and inorganic solutes in dissolved state.	Serum is clear, watery fluid released from a wound after bleeding and clot formation.
Plasma contains fibrinogen which helps in blood clotting	Serum is without fibrinogen and other coagulation factors.

Question 2.
Blood and Lymph
Answer:
Blood and Lymph

Blood	Lymph
It is red in colour due to the presence of haemoglobin in red cells.	It is colourless as red blood cells are absent.
It consists of plasma, RBC, WBC and platelets.	It consists of plasma and very low number of WBC.
Glucose concentration is low.	Glucose concentration is higher than blood.
Clotting of blood is a fast process.	Clotting of lymph is comparatively slow.

Question 3.
Open circulation and Closed circulation
Answer:
Open circulation and Closed circulation

Open Circulation	Closed Circulation
The blood is pumped by the heart into the blood vessels that open into blood spaces (sinuses).	The blood is pumped by the heart into closed blood vessels.
Blood is in direct contact with the tissue cells.	Blood does not come in direct contact with the tissue cells.
Exchange of respiratory gases, nutrients and waste products occurs directly between blood and tissues.	Exchange of respiratory gases, nutrients and waste product between tissues and blood occur via tissue fluid.
Blood returns to the heart slowly.	Blood returns to the heart rapidly.
Respiratory pigment, if present, is dissolved in blood plasma.	Respiratory pigment is present and may be dissolved in plasma but is usually held in red blood corpuscles.

Question 4.
Single circulation and Double circulation
Answer:
Single circulation and Double circulation

Single circulation	Double Circulation
The blood completes only one circuit of circulation, i.e. blood passes through heart only once.	The blood circulates twice through the heart, i.e two circuits of circulation pulmonary and systemic.
The heart is called venous, as it contains only venous blood.	Heart contains both the two arterial and venous blood.
Single circulation occurs in organisims with two chambered heart, e.g. cyclostomes and fishes	Double circulation occurs in four chambered heart with two atriums and two ventricle e.g. Humans and tetrapods.

Question 5.
Haemolysis and Crenation
Answer:
Haemolysis and Crenation

Haemolysis	Crenation
The process of destruction of red blood cells is called haemolysis	The process of developing irregularities on the surface of RBCs due to cell contraction.
It occurs in hypotonic medium due to endo-osmosis	It occurs in hypertonic medium, due to exo-osmosis.
The cell swells up and ultimately burst releasing the haemoglobin in surrounding medium.	The cell shrinks and develops irregularities these shrunken RBC are called as Echinocytes.

Question 6.
Adult haemoglobin and Fetal haemoglobin
Answer:
Adult haemoglobin and Fetal haemoglobin

Adult Haemoglobin	Fetal Haemoglobin
HbA is the form of haemoglobin expressed after birth till the death	Hbf is the predominant form of haemoglobin expressed in the developing foetus.
HbA contains two chains each of α and β sub units where β-globin chain is substituted by d- globin chain.	Hbf also contains two chains of each α and β globin However, β-globin chains are substituted by g- chains.
HbA has lesser affinity for oxygen compared with Hbf	Hbf has higher affinity for oxygen.

Question 7.
Granulocytes and Agranulocytes
Answer:
Granulocytes and Agranulocytes

Granulocytes	Agranulocytes
The leucocytes containing granules in their cytoplasm.	The type of leucocytes which lack granules in their cytoplasam
They have regularly lobed nucleus.	The nucleus is either rounded or qval.
These develops from red bone marrow.	Agranulocytes develops from lympoid tissue.
Granulocytes are of three types, i.e. neutrophils, eosinophils and basophils.	These are of two types i.e lymphocytes and monocytes.

Question 8.
Sickle cell anemia and Haemolytic anemia
Answer:
Sickle cell anemia and Haemolytic anemia

Sickle-cell Anemia	Hemolytic Anemia
An autosome linked recessive trait where a particular mutation in haemoglobin molecule causes RBC to assume sickle-shape	A form of anemia where low RBC count occurs due to excessive destruction of RBCs.
It is caused by the substitution of glutamic acid by valine at the 6th position ofp globin chain of haemoglobin.	It may be due to mechanical causes, infection, autoimmune disorders or congenital abnormalities in the RBCs.

Question 9.
Pulmonary circulation and Systemic circulation
Answer:
Pulmonary circulation and Systemic circulation

Pulmonary Circulation	Systemic Circulation
It is smaller circuit, which carries blood to the lungs and back to the heart.	It is a larger circuit, which supplies blood to the various parts of the body and back to the heart.
It carries deoxygenated blood to the lungs for oxygenation.	It supplies oxygenated blood to all parts of the body.
The blood is pumped by right ventricle and received by left atrium.	The blood is pumped by left ventricle and received by the right atrium.

Question 10.
Bicuspid and Tricuspid valves
Answer:
Bicuspid and Tricuspid valves

Bicuspid Valve	Tricuspid Values
It is formed by two muscular flaps or cusps.	It is formed by three cusps or leaflet like muscular structure.
It guards the opening between the left atrium and left ventricle.	Tricuspid guards the opening between the right atrium and ventricle.

Question 11.
Systole and Diastole
Answer:
Systole and Diastole

Systole	Diastole
The pressure that the blood exerts on the vessels and arteries around the body, during the heartbeats, i.e. when heart is contracting.	Diastolic pressure measures the pressure exerted by the blood on walls of arteries when the heart is relaxed.
Average range is 90-120 mm Hg (adults), 95 mm Hg (infants).	Average range is 60-80 mm Hg (adults) 65 mm Hg (Infants)
Left ventricles during systole contracts.	Ventricles of the heart fills up with blood.
Systole constitutes the maximum pressure in the arteries.	Diastolic blood pressure constitutes the minimum pressure in the arteries.

Question 12.
SA node and AV node
Answer:
SA node and AV node

SA Node	AV Node
It is located at the upper lateral wall of right auricle.	It is situated at the base of right auricle, near auriculovetricular junction.
It generates impulses to initiate heart beating.	Normally it does not generate impulse, but strengthen them.
SA node is also called pacemaker.	AV node is also called pacesetter.
It supplies signals directly to auricles.	It supplies signals to ventricles.
It is not associated with bundle of His and Purkinje fibres.	It is associated with bundle of His and Purkinje fibres.

Question 13.
Hemophilia A and Hemophilia B
Answer:
Hemophilia A and Hemophilia B

Hemophilia A	Hemophilia B
It is caused by deficiency of factor (VIII).	It is caused by deficiency of factor IX.
Also known as the classic hemophilia it is very common in occurrence.	It is also known as Christmas disease and it is very rare in occurrence.

Question 14.
Haemoglobinopathy and Thalasemia
Answer:
Haemoglobinopathy and Thalasemia

Haemoglobinopathy	Thalasemia
A genetic defect resulting in abnormal structure of one of the globin chains of hemoglobin.	An autosome linked recessive disease occurring due to either mutation or deletion of genes resulting in reduced rate of synthesis of one of the globin chains.
Abnormal polypeptides are produced.	The polypeptides are normal.
Abnormal haemoglobin produced due to mutant genes are identified as haemoglobin C, E, I, J and S, etc.	If there is decreased synthesis of α-globin it is known as α- thalassemia – if β-globin synthesis decreases it is called β-thalassemia.

Question 15.
Arteriosclerosis and Atherosclerosis
Answer:
Arteriosclerosis and Atherosclerosis

Arteriosclerosis	Atherosclerosis
The thickening, hardening and loss of elasticity of arterial walls	It is a specific type of arteriosclerosis. It refers to buildup of fats, cholesterol and other substances in the artery walls.
Due to occlusion of the arterial lumen, total peripheral resistance increases, leading to hypertension and heart failure.	Atherosclerosis progress towards heart failure, coronary artery disease and ischemic heart disease.

Question 16.
Flutter and Fibrillation
Answer:
Flutter and Fibrillation

Flutter	Fibrillation
The atrium beats regularly, but faster than the usual and more than ventricles.	The atria beats irregularly.
Less common in occurrence.	Commonly occurs in old age people who have heart conditions associated with atrial contraction.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 17 Breathing and Exchange of Gases Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 17 Question Answer Breathing and Exchange of Gases

Breathing and Exchange of Gases Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Choose the correct answer

Question 1.
When does the frog respire by the skin?
(a) While in water
(b) During hibernation
(c) While on land
(d) During all the times
Answer:
(c) While on land

Question 2.
The exchange of gases in the lung alveoli occurs by
(a) active transport
(b) diffusion
(c) passive transport
(d) None of these
Answer:
(b) diffusion

Question 3.
The amount oxygen taken in and carbon dioxide released during quiet breathing in
(a) 500 mL
(b) 3000 mL
(c) 1000 mL
(d) 5000 mL
Answer:
(a) 500 mL

Question 4.
If the CO₂ concentration in the blood increases, the breathing will
(a) increases
(b) stop
(c) decreases
(d) remain unaffected
Answer:
(a) increases

Question 5.
If a tissue is having inadequate supply of oxygen, the condition is called
(a) Hypoxia
(b) Asphyxia
(c) Anoxia
(d) Anemia
Answer:
(a) Hypoxia

Question 6.
The respiratory centre that regulates breathing is located in which part of the brain?
(a) Cerebral hemisphere
(b) Hypothalamus
(c) Diencephalon
(d) Medulla oblongata
Answer:
(d) Medulla oblongata

Question 7.
The quantity of 500 mL of air during quiet breathing in man refers to the
(a) residual volume
(b) vital capacity
(c) tidal volume
(d) dead space air
Answer:
(c) tidal volume

Question 8.
Which structure in pharynx prevents the entry of food into the respiratory tract?
(a) Larynx
(b) Glottis
(c) Gullet
(d) Epiglottis
Answer:
(b) Glottis

Question 9.
Which of the following prevents the collapse of the trachea?
(a) Diaphragm
(b) Muscles in the wall
(c) Cartilaginous rings
(d) None of the above
Answer:
(c) Cartilaginous rings

Question 10.
The enzyme involved in CO₂ transport by blood is
(a) carboxylase
(b) carbonic anhydrase
(c) carboxykinase
(d) None of these
Answer:
(c) carboxykinase

Question 11.
What is the rate of breathing in a normal healthy man at rest?
(a) 15-20 times/min
(b) 20-30 times/min
(c) 10-15 times/min
(d) 40-50 times/min
Answer:
(a) 15-20 times/min

Answer each of the following is one or two words

Question 1.
What type of respiration is seen in the frog during hibernation?
Answer:
Cutaneous respiration

Question 2.
What type of respiration is seen in endoparasites like the liver fluke and the filarial worm?
Answer:
Tracheal respiration

Question 3.
What is the mode of respiration of the frog, while it is in water?
Answer:
Branchial respiration

Question 4.
What type of respiration is seen in insects?
Answer:
Tracheal respiration

Question 5.
In which part of the body is a Schneiderian membrane located?
Answer:
Nasal cavity (nose)

Question 6.
What is the major form of oxygen transport by the blood?
Answer:
Oxyhaemoglobin

Question 7.
What is the major of CO₂ transport by the blood?
Answer:
Bicarbonate

Question 8.
Name the organ in man, which produces speech?
Answer:
Larynx

Question 9.
What is the prosthetic group present in the haemoglobin molecule?
Answer:
Heme

Question 10.
What is the respiratory pigment present in arthropods like the prawn?
Answer:
Haemocyanin

Question 11.
Which muscles in the thoracic wall bring about inspiration?
Answer:
External intercostal muscles

Question 12.
What is the muscular partition that divides the thoracic and abdomnal cavities?
Answer:
Diaphragm

Question 13.
In which part of the mammalian brain the respiratory centre is located?
Answer:
Medulla oblongata

Question 14.
How many pair of spiracles are present in cockroach?
Answer:
10 pairs

Question 15.
What type of gill is found in cartilaginous fish?
Answer:
Lamellibranch

Question 16.
What type of gill is found in the bony fish?
Answer:
Filiform or pectenate

Question 17.
What is the oxygen carrying capacity of the human haemoglobin?
Answer:
16-25 mL O₂/dL

Short Answer Type Questions

Differentiate between

Question 1.
Anabolism and Catabolism
Answer:
Differentiate between anabolism and catabolism are

Anabolism	Catabolism
It is a metabolic process.	It is also a metabolic process.
In this, small molecules are connected with each other to form large molecules.	In this, the large molecules are broken into small monomers.
Anabolism require the ATP produced via catabolism. e.g. photosynthesis, Assimiliation.	Catabolism is independent of anabolism, e.g. respiration, etc.

Question 2.
Anaerobic respiration and Aerobic respiration
Answer:
Differentiate between anaerobic respiration and aerobic respiration are

Anaerobic respiration	Aerobic respiration
It does not require oxygen.	It takes place in the presence of oxygen.
It may or may not release carbon dioxide.	It always releases carbon dioxide.
It provides less energy.	It provides much more energy.
It takes place in cytoplasm.	It occurs both in cytoplasm (glycolysis) and in the mitochondria (Krebs cycle and Electron Transport Chain).
e.g. In anaerobic bacteria, yeast, muscles and parasitic worms like Ascaris, Fasciola, Taenia.	e.g. In most of plants and animals.

Question 3.
Cutaneous respiration and Pulmonary respiration
Answer:
Differentiate between cutaneous and pulmonary respiration are

Cutaneous respiration	Pulmonary respiration
Respiration occurs across the skin or outer integument of an organism.	It occurs via lung.
It occurs in different form such as ventilation, diffusion and convection.	It includes breathing, exchange of gases in lungs, transport of gases by blood.
It occurs in insect, amphibian, fish, etc.	Humans, etc.

Question 4.
Inspiration and Expiration
Answer:
Differentiate between inspiration and expiration are

Inspiration	Expiration
It is an active process by which fresh air enters the lungs.	It is a passive process by which CO2 is expelled out from the lungs.
It can occur if the pressure with in the lungs is less than the atmospheric pressure.	It takes place when the intra pulmonary pressure is higher than the atmospheric pressure.
In this process diaphragm and external intercostal muscles play an important role.	In this process diaphragm and internal intercostal muscles take part.
This result into decrease in the intra-pulmonary pressure.	This result into increase in the intra pulmonary

Question 5.
External intercostal muscle and internal intercostal muscle
Answer:
Differentiate between and external intercostal muscles and internal intercostal muscles are

External intercostal muscles	Internal intercostal muscles
These muscles occur between the ribs.	These muscles also occur between the ribs.
These muscles contract and pull the ribs and sternum upward and outward.	These muscles contract and pull the ribs downwards and inward.
This increases the volume of the thoracic cavity.	These reduce the size of the thoracic cavity.
These muscles help in inspiration.	These help in expiration.

Question 6.
Quiet breathing and Forced breathing
Answer:
Differentiate between quiet breathing and forced breathing are

Quiet breathing	Forced breathing
During insipiration the diaphragm contracts. External intercostal muscles contract.The ribs move forward and outward. The thoracic volume increases. The intra pulmonary pressure decreases to about -3 mm Hg.	The action of the external intercostal muscles aided by the scaleness and sterrocleidomastoid muscles decreases the intra pulmonary pressure to -20 mm Hg.
During expiration The diaphragm relaxes. Internal intercostal muscle contracts. The ribs move backward and inward. The thoracic volume decreases. The intra pulmonary pressure increases to about +3 mm Hg.	The contraction of the abdominal muscles and internal intercostal muscles decreases the intra pulmonary pressure to about +30 mm Hg.

Question 7.
Tracheal respiration and Branchial respiration
Answer:
Differentiate between tracheal respiration and branchial respiration are

Tracheal respiration	Branchial respiration
Respiration through trachea is called tracheal respiration.	Respiration through gills is called branchial respiration.
It is seen in insects, centipedes, ticks, some mites and spiders.	It is seen in fishes.

Question 8.
Tidal volume and Vital capacity
Answer:
Differentiate between tidal volume and vital capacity are

Tidal volume	Vital capacity
It is the volume of air inspired or expired during normal breathing.	It is the maximum volume of air inspired during forced breathing.
A healthy man can inspire or expire about 6000-8000 mL of air per minute.	Vital capacity varies from 3400 mL-4800 mL
It is lowest in ail pulmonary volumes.	This include tidal volume, inspiratory and expiratory reserve volume.
It shows lung volume.	It shows lung capacity.

Question 9.
Myoglobin and Haemoglobin
Answer:
Differentiate between myglobin and hoemoglobin are

Myoglobin	Haemoglobin
It occurs as a monomeric protein.	It occurs as a tetrameric protein.
It acts as a secondary carrier of oxygen in the muscular tissue.	It is the system wide carrier of oxygen on RBC.
It consists of 8 right handed α-helices and each protein molecule contains on heme prosthetic group.	Haemoglobin is composed of two α-subunits and two ß-subunits. Each α-subunits has 144 residues, and each ß-subunit has 146 residues.
It transport and store oxygen.	It only transport oxygen.
It binds oxygen more tightly and easily.	It binds oxygen loosely and with difficulty.

Question 10.
Deoxyhaemoglobin and Oxyhaemoglobin
Answer:
Differentiate between oxyhaemoglobin and deoxyhoemoglobin are

Oxyhaemoglobin	Deoxyhaemoglobin
It is the form of haemoglobin, loosely combined with oxygen, present in arterial and capillary blood.	It is the form of haemoglobin that has released its oxygen.

Question 11.
Carbaminohaemoglobin and Carboxyhaemoglobin.
Answer:
Differentiate between carbaminoheamoglobin and carboxyhaemoglobin are

Carbaminoheamoglobin	Carboxyhaemoglobin
It is the combination of carbon dioxide and haemoglobin (CO2 HHb).	it is formed when inhaled carbon monoxide combines with haemoglobin in the blood (COHb Hb).
It is one of the forms in which carbon dioxide exists in the blood. This chemical complex is after the release of oxygen by the haemoglobin to a tissue cells.	In the body when inhaled carbon monoxide occupies the sites on the haemoglobin molecules that normally bind with oxygen and which is not readily displaced form-the molecules.

Question 12.
Substrate level phosphorylation and Oxidative phosphorylation
Answer:
Differentiate between substrate level phosphorylation and oxidative phosphorylation

Substrate level phosphorylation	Oxidative phosphorylation
It directly transfers a phosphate group from substrate to ADP to produce ATP.	It is a process by which energy released by chemical oxidation of nutrients is used for the synthesis of ATP.
Energy is generated from a coupled reaction for this process.	Energy generated from the reaction of electron transport chain is used for this process.
A small difference of redox potential is generated in substrate level phosphorylation.	A large difference is generated to power this phosphorylation.
This occurs under both aerobic and anaerobic conditions.	This occurs under aerobic conditions.
Substrates are partially oxidised.	Electron donors are completely oxidised
Substrate level phosphorylation occurs in mitochondria.	Oxidative phosphorylation occurs in the mitochondira.
This does not use O2 or NADH for the formation of ATP.	This uses O2 and NADH to produce ATP.

Question 13.
Asthma and Emphysema
Answer:
Differentiate between asthma and emphysema are

Asthma	Emphysema
It is usually due to an allergic reaction to foreign substances that affect the respiratory tract.	It is an inflation or abnormal distension of the bronchioles or alveolar sacs of the lungs.
Allergens stimulate the release of histamine from the mast cells.	Major causes are cigarette smoking and the inhalation of the other smoke.
It causes contraction of bronchiolar smooth muscles.	Many of the septa between the alveoli are destroyed and much of the elastic tissue of the lungs is replaced by connective tissue.
The symptoms of asthma may be coughing, wheezing, etc.	The exhalation becomes more difficult. The lungs remain inflated.

Write Short Notes

Question 1.
Cutaneous respiration
Answer:
Cutaneous Respiration
Many small organisms obtain O₂ by diffusion through their body surfaces. They do not have any specialised respiratory organ nor do they have blood circulation. In animals that have defined circulatory system and readily permeable vascular skins gaseous exchange takes place through integument. Animals like earthworm, leeches and newly hatched fish fries, obtain their oxygen through their skin, Apart from these animals like some amphibians and fishes also rely on cutaneous respiration during emergencies or use it as alternative to the gills or lungs.

Question 2.
Haldane effect
Answer:
Haldane effect states that binding of oxygen with haemoglobin tends to displace CO₂ from the blood.
It is quantitatively more important in promoting CO₂ transport than the Bohr’s effect in O₂ transport. Thus, Haldane effect and Bohr’s effect complement each other.

Question 3.
Bohr effect
Answer:
Bohr effect:
The Bohr effect refers to the observation that causes increase in the CO₂ partial pressure of blood or decreases blood pH resulting in a lower affinity of haemoglobin for oxygen. This manifests as a right ward shift in the oxygen-haemoglobin dissociation curve and yields enhanced unloading of oxygen by haemoglobin.

Question 5.
Chloride shift/Hamburger phenomenon
Answer:
Hamburger’s Phenomenon This is the phenomenon in which an exit of bicarbonate ions considerably changes ionic balance between the plasma and erythrocytes. ‘This ionic balance is restored by the diffusion of chloride ions from the plasma into the erythrocytes.

Question 6.
Residual volume
Answer:
(iv) Residual Volume (RV) It is the volume of air remaining in the lungs even after a forcible expiration. It is about 1100-1200 mL. It cannot be measured by spirometry.

Question 7.
Vital capacity
Answer:
Vital Capacity (VC)
It is the maximum volume of air a person can breathe in after a forced expiration, or the maximum volume of air a person can breathe out after a forced inspiration.
This includes TV+ IRV+ ERV.
It varies from 3400-4800 mL depending upon age, sex and height of individual.

Question 8.
Role of diaphragm in respiration
Answer:
Role of Diaphragm in Respiration During inspiration diaphragm is lowered by the contraction of its muscle fibres and becomes flat.This causes an increases in the volume of thoracic chamber in the antero-posterior axis. During expiration diaphragm muscles fibres relax making it convex, decreasing volume of the thoraic cavity.

Question 9.
Advantages and disadvantages of cutaneous respiration
Answer:
Advantage and Disadvantage of Cutaneous respiration Cutaneous respiration is advantages to small animals to obtain 02 by diffusion through their body surfaces as they do not have specialised respiratory organ nor do they have blood circulation. Its major disadvantage is that a lot of water loss occurs in this way.

Question 10.
Counter current flow in gill respiration
Answer:
Counter Current Flow in Gill Respiration It means the blood flows through the gills in the opposite direction as the water flowing over the gills. This flow pattern ensures that as the blood progresses through the gills and gains oxygen from the water, it encounters increasingly fresh water with a higher oxygen concentration, so that it able to continuously offload oxygen into the blood.

Question 11.
Structure and functions of larynx
Answer:
Larynx It is the upper part of trachea. It allows the air to pass into lungs. Nasopharynx opens through glottis of the larynx into trachea. Glottis is a slit-like aperture that remains open except during swallowing.
The glottis bears a leaf-like cartilaginous flap, the epiglottis at its anterior region. It closes the glottis to check the entry of food during swallowing.
Larynx helps in sound production and hence, called the sound box.

Question 12.
Bronchial tree
Answer:
Bronchial Tree It is the branching system of bronchi and bronchioles, conducing air from the wind pipe into the lungs. The bronchial tree is named for its resemblance to the branches of a tree as larger tubes perpetually concede of smaller tube in an intricate framework of branches.

Question 13.
Control of ventilation
Answer:
Control of Ventilation It refers to the physiological mechanism involved in the control of ventilation, which refers to the movement of air into and out of the lungs, ventilation facilitates respiration. It is under dual control, i. e. nervous and chemical control.

Question 14.
Hering-Breur reflex
Answer:
Herring-Breurer reflex Inspiration is controlled by the stretch receptors located in the bronchial tree and the lung wall, which limit maximum inspiration. These receptors send impulses to the inspiratory centre to inhibit it when maximum inflation has reached. Impulses also reach the expiratory centre to stimulate it. External intercostal muscles relax as a result. This is known as Herring Breures Reflex.

Question 15.
Structure of haemoglobin
Answer:
Structure of Haemoglobin Heamoglobin is the oxygen binding protein of red blood cells and is a globular protein with quaternary structure. Hemoglobin consists of four polypeptide subunits, i.e. 2 alpha chains and 2 beta chains.

Question 16.
Myoglobin
Answer:
Myoglobin It is a protein found in the muscle cells of animals. It functions as an oxygen-storage unit, providing oxygen to the working muscles. In humans myoglobin is only found in the bloodstream after,muscles injury.

Question 17.
Role of haemoglobin as a buffer
Answer:
Role of Haemoglobin as a Buffer Haemoglobin act as buffer at the level of the lungs, where O₂ is more. Haemoglobin release H⁺ and combines with O₂ (Oxyhaemoglobin is a stronger acid). The released H⁺ can combine with bicarbonate to form H₂O and CO₂ (catalysed by carbonic anhydrase enzyme). This CO₂ formed is removed by lungs.

Question 18.
Carbon monoxide poisoning
Answer:
The affinity of deoxyhaemoglobin (containing Fe²⁺) for carbon monoxide is about 250 times greater than that of oxygen. Thus, haemoglobin quickly takes up any available carbon monoxide in preference to oxygen to form a stable compound called carbon monoxyhaemoglobin or carboxyhaemoglobin. If it happens, vital organs like the heart and brain starve without oxygen.

This result in carbon monoxide poisoning. The body gets collapsed unless exposure to carbon monoxide is quickly stopped and pure oxygen and a small amount of CO₂ is inhaled. This mainly happens due to automobile pollution.

Some drugs and oxidising agents oxidise the normal ferrous valency state of iron (Fe²⁺) of haemoglobin. Thus, formation of methaemoglobin occurs normally.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 16 Digestion and Absorption Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 16 Question Answer Digestion and Absorption

Digestion and Absorption Class 11 Questions and Answers CHSE Odisha

Multiple Choice Questions

Question 1.
Glucose is stored as glycogen in
(a) pancreas
(b) liver
(c) stomach
(d) kidney
Answer:
(b) liver

Question 2.
Ascorbic acid is also known as
(a) vitamin-B
(b) vitamin-C
(c) vitamin-E
(d) vitamin-D
Answer:
(b) vitamin-C

Question 3.
Which gland function as both exocrine and electrone glands?
(a) Salivary gland
(b) Gastric gland
(c) Pancreas
(d) Liver
(c) Pancreas

Question 4.
Pepsinogen is activated by
(a) trypsin
(b) chymotrypsin
(c) hydorchloric acid
(d) pepsin
Answer:
(c) hydorchloric acid

Question 5.
Trypsin converts
(a) fats into fatty acids
(b) proteins into peptones
(c) polysaccharides into maltose
(d) peptones into amino acids
Answer:
(b) proteins into peptones

Question 6.
The end products of fat digestion are fatty acids and
(a) glycerol
(b) cholesterol
(c) phospholipid
(d) glycolipid
Answer:
(a) glycerol

Question 7.
The posterior free part of the soft palate is known as
(a) glottis
(b) gullet
(c) epiglottis
(d) uvula
Answer:
(d) uvula

Question 8.
The number of teeth in the deciduous set of human being is
(a) 32
(b) 20
(c) 18
(d) 24
Answer:
(b) 20

Question 9.
The opening of the middle ear into the pharynx is known as
(a) eustachian opening
(b) external nostril
(c) internal nostril
(d) glottis
Answer:
(a) eustachian opening

Question 10.
The gastrointestinal hormone that stimulates the contraction of the gall bladder is known as
(a) gastrin
(b) chloecystokinin
(c) secretin
(d) molitin
Answer:
(b) chloecystokinin

Question 11.
The wall of the stomach of human is histologically unique in possessing
(a) submucosa
(b) circular muscle
(c) longitudinal muscle
(d) oblique muscle
Answer:
(a) submucosa

Question 12.
Gastrin is secreted from the mucosa of
(a) antrum
(b) fundus
(c) body
(d) pylorus
Answer:
(d) pylorus

Question 13.
Brunner’s glands are present in the mucosa of
(a) ileum
(b) jejunum
(c) duodenum
(d) colon
Answer:
(c) duodenum

Question 14.
Secretin stimulates the release of
(a) bicarbonate ions into the pancreatic juice
(b) water into the pancreatic juice
(c) enzymes into the pancreatic juice
(d) Ca2+into the pancreatic juice
Answer:
(a) bicarbonate ions into the pancreatic juice

Question 15.
Kwashiorkor, a nutritional disorder, caused due to the deficiency of
(a) carbohydrates
(b) lipids
(c) vitamins
(d) proteins
Answer:
(d) proteins

Question 16.
In a polypeptide, the amino acids are joined together by
(a) glycosidic bonds
(b) phosphodiester bonds
(c) peptide bonds
(d) hydrogen bonds
Answer:
(c) peptide bonds

Very Short Answer Type Questions

Question 1.
Name the mass of vascular connective tissue in a tooth.
Answer:
Pulp cavity

Question 2.
Name the water soluble vitamins.
Answer:
Vitamin-B, vit-C.

Question 3.
Enlist the fat soluble vitamins.
Answer:
Vit-A, vit-D.

Question 4.
Name three divisions of the small intestine.
Answer:
Duodenum, jejunem and ileum.

Question 5.
Name the vestigial organ in the alimentary canal of human.
Answer:
Appendix

Question 6.
Which gland is the largest gland of the body?
Answer:
Liver

Question 7.
Name the term used for the presence of different types of teeth.
Answer:
Heterodont dentition.

Question 8.
Name two bile pigment.
Answer:
Bilirubin and Bilivirdin.

Question 9.
How many liver lobes are there in human?
Answer:
2

Question 10.
Name the ampulla formed by the joining of the common bile duct and pancreatic duct before opening into the duodenum.
Answer:
Ampulla of vater

Question 11.
Name the phagocytic cell in the liver.
Answer:
Kupffer cells

Question 12.
What is the non-digestive enzyme released in the small intestine?
Answer:
Trypsinogen

Question 13.
Name the enzyme that digest fat.
Answer:
Lipase

Question 14.
Name the structure that is formed by the grouping of hepatic artery, hepatic portal vein and bile duct in the liver.
Answer:
Portal triad

Question 15.
Give an alternate name for ptyalin.
Answer:
Salivary amylase

Question 16.
Name the end proudct of protein digestion.
Answer:
Amino acids

Question 17.
Name the intestinal glands, which secrete succus entericuus.
Answer:
Crypts of Lieberkuhn

Fill in the Blanks

Question 1.
The fibrous connective tissue that cements the root of the tooth to the socket is known as …………….. .
Answer:
Enamel

Question 2.
The last molar teeth in human are known as ………… teeth.
Answer:
Wisdom

Question 3.
………… is the hardest substance in the human body.
Answer:
Enamel

Question 4.
The longitudinal folds of the oesophageal mucosa are known as …………… .
Answer:
Oesophageal rugal

Question 5.
The passage of the bolus through the lumen of oesophagus in spurts is known as ………….. .
Answer:
Peristalsis

Question 6.
The opening of the common bile duct and pancreatic duct into the duodenum is guarded by a sphincter, called ………….. .
Answer:
Sphincter of addi

Question 7.
The gastrointestinal hormone that stimulates the secretion of enzymes into the pancreatic juice is known as …………. .
Answer:
Pancrozymin

Question 8.
The connective tissue sheath, surrounding a liver lobule is known as ……………. .
Answer:
Glisson’s capsule

Question 9.
Bile facilitates the digestion of fat by dividing large fat droplets into a number of smaller droplets. This function of bile is known as ………… .
Answer:
Emulsification

Question 10.
Intestinal juice is alternately known as …………… .
Answer:
Succus entericus

Question 11.
There are ………… pairs of salivary glands in human.
Answer:
3

Question 12.
………….. is the substrate for ptyalin.
Answer:
Starch

Question 13.
The yellow colour of the stool is due to the presence of a pigment ……………. .
Answer:
Bilirubin

Question 14.
Limit dextrinase or a-Dextrinase is alternately known as ………….. .
Answer:
Isomealtase

Question 15.
Synthesis of glucose from non-carbohydrate sources is known as ……………. .
Answer:
Gluconeogonesis

Question 16.
Rennin acts on the milk protein …………. and changes it into …………… in the presence of Ca2+.
Answer:
Paracasein, calcium paracaseinate

Question 17.
Bile is secreted by ………… and stored in ………….. .
Answer:
Liver, gall bladder

Question 18.
The coagulation factors, prothrombin and fibrinogen are synthesised in ………….. .
Answer:
liver

Match the Words

Group A	GroupB
1. Chief cell	(a) Small intestine
2. Meissner’s plexus	(b) Insulin
3. Trypsinogen	(c) Bilirubin
4. Indigestion	(d) Food poisoning
5. Islets of Langerhans	(e) Pepsinogen
6. Marasmus	(f) HCl
7. Jaundice	(g) Lacteal
8. Chyle	(h) Pancreatic juice
9. Fatty acid	(i) Sub-mucosa
10. Oxyntic cell	(j) Nutritional deficiency

Answer:

Group A	GroupB
1. Chief cell	(e) Pepsinogen
2. Meissner’s plexus	(i) Sub-mucosa
3. Trypsinogen	(h) Pancreatic juice
4. Indigestion	(d) Food poisoning
5. Islets of Langerhans	(b) Insulin
6. Marasmus	(j) Nutritional deficiency
7. Jaundice	(c) Bilirubin
8. Chyle	(a) Small intestine
9. Fatty acid	(g) Lacteal
10. Oxyntic cell	(f) HCl

Short Answer Type Question

Question 1.
What do you mean by intracellular digestion?
Answer:
Intracellular Digestion
It is the simplest type of digestion, which occurs entirely inside the cell. The food material is engulfed by the cell into a food vacuole. Then lysosomes containing digestive enzymes fuse with the food vacuole and consequently the food is digested. The digested products are absorbed into the surrounding cytoplasm by simple diffusion. The residual undigested food is eliminated to the outer side by egestion (e.g. all protozoans, sponges and Hydra).

Posterior end

Question 2.
Explain the gustatory function of the tongue.
Answer:
Tongue acts as a gustatory organ for perceiving taste. It bears numerous taste buds (organ of taste). The circumvallate papillae of tongue bear around 100 taste buds/papilla. These taste buds open on tongue’s surface through a gustatory pore.

Question 3.
Write the dental formula of the permanent set of man.
Answer:

Question 4.
Write the sub-divisions of the pharynx and the openings discharging into the pharynx and the openings leading from the pharynx.
Answer:
Pharynx possess 3 divisions namely nasopharynx, oropharynx and laryngopharynx.
The opening discharging into pharyx is called buccopharyngeal cavity.
The openings leading from pharynx are gullet (into oesophagus) and glottis (into larynx).

Question 5.
Mention about the divisions of the stomach of man.
Answer:
Human stomach is divided into 4 regions namely cardiac part (Cardia), fundus, body and pyloric part (Pylorus).

Question 6.
What do you mean by peristalsis and antiperistalsis?
Answer:
Peristalsis is successive contraction and relaxation of oesophageal muscle layers through which food is conducted to the stomach.
Antiperistalsis is the contraction and relaxation in a reverse rhythm. It results in hiccups.

Question 7.
What are Peyer’s patches and what is their function?
Answer:
Peyer’s Patches are small nodules of lymphoid tissue in the ileum. It is the place of maturation of bone marrow lymphocytes as B-lymphocytes. ,

Question 8.
What are the four histological layers in the alimentary canal of man from outer to inner?
Answer:
Histological layer of alimentary canal from outer to inner side are mucosa, submucosa, muscularis externa and serosa.

Question 9.
How is the secretion of the gastric juice regulated?
Answer:
As soon as the food bolus reaches ,the stomach, the enteroendocrine cells of the antral mucosa secrete a hormone called gastrin. It stimulates the gastric glands to produce gastric juice. The gastric juice consist of mucus, hydrochloric acid (HC1), proenzymes-sinogen and pro-rennin, and gastric lipase.

Question 10.
Pancreas is a mixocrine gland. Explain it.
Answer:
Pancreas functions both as an exocrine and an endocrine gland. Hence, it is a mixocrine gland.
Its exocrine part possess acini which secrete pancreatic juices. The endocrine part possess Islet of Langerhans.

Question 11.
If enterokinase does not have a hydrolytic function in digestion, what specific role does it play?
Answer:
Enterokinase is present in pancreatic juices secreted by acini or lobules. It is an intestinal activator enzyme which activates trypsinogen into trypsin.

Question 12.
What are the physiological roles of insulin and glucagon? Where are these hormones secreted from the pancreas?
Answer:
Insulin and glucagon are two antagonistic hormones secreted by P-cell and a-cells of I-slet of Langerhans respectively.
Insulin lowers the blood glucose and glucagon promotes glucose formation in body.

Question 13.
Distinguish between glycogenesis and glycogenolysis.
Answer:
Glycogenesis It converts excess glucose into glycogen with the action of insulin hormone.
Glycogenolysis It converts glycogen into glucose with the action of glycogen hormone.

Question 14.
What do you understand by curdling of milk?
Answer:
Rennin hydrolyses the milk protein, casein into para-casein and whey protein (peptone-like substance). Paracasein is transformed into soluble calcium para-cascinate in the presence of calcium ions. This is known as clotting or curdling of milk.

Question 15.
What are exo and endopeptidases?
Answer:
All proteases of the pancreatic and intestinal juices fall under 2 broad categories as follows
(a) Eendopeptidase they hydrolyses internal peptide bonds, e.g. trypsin, elastase, etc.
(b) Exopeptidase they hydrolyses peptide bonds from C- or N- ends in a sequence.
e.g. carboxypeptidase.

Question 16.
What do you understand by amino and carboxypeptidases?
Answer:
Aminopeptidases There peptide bonds are hydrolysed by exopeptidase through N-terminus.
Carboyxpeptidases There peptide bonds are hydrolysed by exopeptidases through C-lerminus.

Question 17.
Comment on the absorption of glucose through the intestine following digestion.
Answer:
The end products of carbohydrate digestion, monosaccharides, such as glucose, fructose, galactose, etc., are rapidly absorbed into the blood stream across the wall of the small intestine. This absorption or transport is dependent on the concentration of Na⁺ in the intestinal lumen. A high Na⁺ concentration in the lumen facilitates the transport of glucose into the epithelial cells. Both glucose and Na⁺ are transported into the cells by a membrane transporter (a transporter is a membrane integral pfotein), called cotransporter or more specifically, Sodium Dependent Glucose Transporter (SGLT).

Following the transport into the epithelial cells, Na⁺ is released back into the intestinal lumen, while glucose is released into the cytosol. Thus, glucose absorption is a secondary active transport. The energy for glucose transport is provided by the active transport of Na⁺ out of the cell. The monosaccharides absorbed into the cytosol and then into the interstitium, enter into the hepatic portal circulation.

Question 18.
What are Kwashiorkor and Marasmus related to?
Answer:
Kwashirokor and Marasmus are Protein Energy Malnutrition (PEM) diseases. This nutritional deficiency is caused by the intake proteins of less calorific value for a long time.

Write short notes on

Question 1.
Dental formula of man
Answer:
Dental Formula of Man The number of each type of teeth can be expressed by a dental formula, which is the arrangement teeth in each half of the upper and the lower jaw in order I, C, Pm and M.
Milk teeth of man include 8 incisors, 4 canines and 8 molars. Molars of milk teeth are shed off and premolars of permanent teeth take their place. The permanent teeth are 8 incisors, 4 canines, 8 premolars and 12 molars. Thus,
12 teeth (8 premolars and 4 molars) are monophyodont. Dental formulae of milk teeth and permanent teeth of human are given below \

Dental formula of milk teeth = \(\frac{212}{212}\) x 2 = 20

Dental formula of permanent teeth = \(\frac{2123}{2123}\) × 2 = 32

Question 2.
Salivary glands of man
Answer:
Salivary Glands of Man In man, the salivary glands occurs in three pairs. Parotid, sublingual and submandibular glands. The ducts of parotid gland open into the oral cavity near the upper second molars. The ducts of sublingual gland open into the floor of the oral cavity. Submandibular glands are located at an angle of the lower jaw. Their ducts open into the oral cavity near the lower central incisors.

The parotid glands secrete much of salivary amylase or a-amylase (ptyalin). Sub-lingual and submandibular salivary secrete salivary amylase and mucus.

Question 3.
Larynx
Answer:
Larynx It is commonly called the voice box. These are situated below where the tract of the pharynx splits into the trachea and the oesophagus. Sound is generated in the larynx, and that is where pitch and volume are manipulated.

Question 4.
Pharynx
Answer:
Pharynx It is a small funnel-shaped chamber located behind the oral cavity. It serves as a common passage for both food and air, i.e. it communicates with both oesophagus and trachea.

Question 5.
Peristalsis
Answer:
Peristalsis It is produced by involuntary contraction of circular muscles in the oesophagus lying just above and around the top of the bolus and simultaneous contraction of the longitudinal muscles lying around the bottom of and just below the bolus.
It pushes the food in the forward direction (away from the mouth).

Question 6.
Gastric glands
Answer:
Gastric Glands The glands of stomach are called gastric glands. These are present in the mucosa of the stomach. The gastric gland contains the following three types of secretory cells, i.e.
(a) Mucous or goblet cells, secretes alkaline mucus.
(b) Peptic or chief or zymogenic cells, secretes inactive precursors of gastric enzymes,
(c) Parietal or oxyntic cells, secretes HC1 and castle’s intrinsic factor.

Question 7.
Peyer’s patches
Answer:
Peyer’s Patches Small nodules of lymphatic tissue can be seen along the entire length of the small intestine. In some places, particularly along the ileum, these nodules are clustered together in groups called peyer’s patches. These help in destroying harmful bacteria of the region.

Question 8.
Islet of Langerhans
Answer:
Islet of Langerhans The endocrine part of the pancreas consists of groups of islets of Langerhans. The human pancreas has about one million islets. Each islet of Langerhans consists of four types of cells, i.e. α-cells, ß-cells, δ-cells and pancreatic polypeptides cells (PP cells) α-cells secretes glucagon hormone which converts glycogen into glucose.
ß-cells secrete insulin which converts glucose into glycogen.
δ-cells secrete somatostatin which inhibits the secretion of glycogen and inslulin,
PP cells secrete pancreatic polypeptide whcih inhibits the release of pancreatic juice.

Question 9.
Gastrointestinal hormones
Answer:
Gastrointestinal Hormones The gastrointestinal hormones constitute a group of hormones secreted by enteroendocrine cells in the stomach, pancreas and small intestine.
The gastrointestinal hormones can be divided into three main groups based upon their chemical structure.

• Gastrin-Cholecystokinin Family gastrin and cholecystokinin
• Secretin Family secretin, glucagon
• Somatostatin Family

Question 10.
Protein deficiency disorders
Answer:
Protein Deficiency Disorders Proteins are used as structural components of tissues, as channels, transporters, regulatory molecules and enzymes. Amino acids, the units of proteins, are required for the formation, growth and repair of body cells. It protein are not provided properly, two deficiency diseases named Marasmus and Kwashiorkor are caused in children.

Kwashiorkor is protein deficiency with adequate energy intake whereas marasmus is inadequate energy intake. Protein wasting in kwashiorkor generally leads to edema and ascites, while muscular wasting and loss of subcutaneous fat are the main clinical signs of marasmus.

Question 11.
Absorption of digested food
Answer:
Absorption of Digested Food After the conversion of large and complex food particles into their respective simpler forms, the next step in digestion process is the absorption of these small and simple particles.

It is the process by which end products of digestion pass through the intestinal mucosa into the blood or lymph. The site of absorption is mainly small intestine. Absorption is carried out by the means of diffusion, active, passive or facilitated transport mechanism.
The carbohydrates are mainly absorbed in the form of monosaccharides and proteins in the form of amino acids.

Question 12.
Indigestion
Answer:
Indigestion Indigestion is the process, in which food is not properly digested by digestive system that leads to a feeling of fullness.
The incomplete digestion of food is due to one of the following causes, i.e. inadequate secretion of digestive enzymes and gastrointestinal hormones, anxiety, food poisoning, over eating, spicy food, etc.

Question 13.
Constipation
Answer:
Constipation It is the condition of difficult or irregular defecation during which the faces are retained within the rectum (large intestine) for a longer time the normal. Due to this, more amount of water is absorbed from the faecal matter making it hard and dry to expel out.

During constipation slowing down of peristaltic movements of alimentary canal is visible. A common treatment is a mild laxative, such as milk of magnesia, which induces defecation.

Question 14.
Vomiting
Answer:
Vomiting It is the forceful ejection of harmful contents of stomach through the mouth. It is not due to the reverse peristalsis of the stomach and oesophagus, instead the major thrust or force for expulsion is from the contraction of diaphragm and abdominal muscles. The reflex action of vomiting is controlled by the vomit centre in the medulla.

Question 15.
Jaundice
Answer:
Jaundice It is the condition in which bile pigments begin to excrete through other parts of the body due to their increased accumulation level in the blood. This occurs due to malfunctioning of liver. Thus, the skin and the white portion of sclera of the eyes turns yellow.

Question 16.
Diarrhoea
Answer:
Diarrhoea It is the condition of abnormal frequency of bowel movement (act of defecation) and increased liquidity of faces, which is caused due to irritation in the lining of the colon.

During diarrhoea, the peristalsis movement gets increased due to which the contents of intenstine pass through rapidly. Thus, reducing the absorption of food and water.

Distinguish between

Question 1.
Intracellular and Extracellular digestions
Answer:
Intracellular digestion and Extracellular digestion

Intracellular digestion	Extracellular digestion
The digestion of food occurs within the cell.	The digestion of food occurs outside the cell in the cavity of alimentary canal.
Digestive enzymes are secreted by the surrounding cytoplasm into the food vacuole.	Digestive enzymes.are secreted by special ceils into the cavity of alimentary canal.
Digestive products are diffused into the cytoplasm.	Digestive products diffuse across the intestinal wall into various parts of the body.
It occurs in unicellular organisms.	It occurs in multicellular organisms.

Question 2.
Teeth of Deciduous set and Permanent set
Answer:
Teeth of Deciduous set and Permanent set

Deciduous set	Permanent set
These are temporary.	These are permanent.
These are 20 in number.	These are 32 in number.
It begins to erupt at the age of 6 months.	It begins to erupt at age of 6 year.
These include 8 incisors, 4 canines, and 8 molars.	These include 8 incisors, 4 canines, 8 premolars and 12 molars.
Dental formula \(\frac{212}{212}\) × 2 = 20.	Dental formula \(\frac{2123}{2123}\) × 2 = 32.

Question 3.
Cardiac stomach and Pyloric stomach
Answer:
Cardiac stomach and Pyloric stomach

Cardiac stomach	Pyloric stomach
It is present near the heart, it is upper portion of the stomach.	It is present in the lower portion.
The gastroesophageal sphincter lies in the opening between oesophagus and stomach .	The pyloric sphincter lies in the opening between stomach and duodenum.

Question 4.
Duodenum and Ileum
Answer:
Duodenum and Ileum

Duodenum	Ileum
It is the shortest, widest part of the small intestine.	It is the longest part of small intestine.
It is U-shaped, the hepatopancreatic ampulla opens into the duodenum.	It is greatly coiled.
The function of duodenum is absorption of iron.	It absorbs bile salts, vitamin-B and remaining digested food particles that do not absorb in the jejunum.

Question 5.
Exocrine pancreas and Endocrine pancreas
Answer:
Exocrine pancreas and Endocrine pancreas

Exocrine pancreas	Endocrine pancreas
It consists of rounded lobules.	It consists of groups of islets of Langerhans.
It secretes an alkaline pancreatic juice with pH 8.4.	It secretes various hormones.
Pancreatic juice contains trypsinogen, chymotrypsinogen, elastase, DNase, RNase, etc.	It contains glucagon, insulin, somatostatin hormones.
The pancreatic juice helps in the digestion of starch, proteins, fats and nucleic acids.	Glycogen hormone converts glycogen into glucose, insulin converts glucose into glycogen.

Question 6.
Circumvallate papillae and Filliform papillae
Answer:
Circumvallate papillae and Filliform papillae

Circumvallate papillae	Filliform papillae
These are usually about 8 to 12 in number.	These are numerous.
Each papilla contains upto 100 taste buds.	These papillae contains tactile receptors, but no taste buds.
These are largest.	These are smallest.
These are found on the upper part of the tongue.	These are found mainly near the centre and most of the upper surface of the tongue.

Question 7.
Brunner’s gland and Crypt of Lieberkuhn
Answer:
Brunner’s gland and Crypt of Lieberkuhn

Brunner’s gland	Crypt of Lieberkuhn
These are found only in the duodenum.	These occur throughout the small intestine between the villi.
They secrete a little enzyme and mucus.	They secrete digestive enzymes and mucus.
The Brunner’s glands open into the crypts of Lieberkuhn.	The mucus is secreted by the goblet cells.

Question 8.
Secretin and Pancreozymin
Answer:
Secretin and Pancreozymin

Secretin	Pancreozymin
It was the first hormone to be discovered by scientists.	The word pancreozymin is derived from pancreas and zymin, which means enzyme producer.
It is secreted by the epithelium of duodenum.	It is secreted by the epithelium of entire small intestine.
It increases secretion of bile. It decreases gastric secretion and motality.	It stimulates the gall bladder to release bile and pancreas to secret digestive enzyme.

Question 9.
Exopeptidase and Endopeptidase
Answer:
Exopeptidase and Endopeptidase

Exopeptidase	Endopeptidase
These enzymes break the bonds between amino acids existing at the end of the polypeptide chain.	These enzymes can breafc peptide bonds between the amino acids in a polypeptide chain.
Carboxypeptidase is an exopeptidase.	Pepsin and trypsin are the endopeptidase.
These can breakdown proteins into monomers.	These cannot breakdown peptides into monomers.

Question 10.
Aminopeptidase and Carboxypeptidase
Answer:
Aminopeptidase and Carboxypeptidase

Aminopeptidase	Carboxypeptidase
It is present in intestinal juice.	It is present in pancreatic juice.
The site of action of this enzyme is small intestine.	It also act in small intestine.
It acts on peptides and convert it in amino acids.	It acts on protease and convert it in dipeptides.

Question 11.
α-1, 4 glycosidase and α-1, 6 glycosidase
Answer:
α-1, 4 glycosidase and α-1, 6 glycosidase

α-1,4 glycosidase	α-1,6 glycosidase
It is glucosidase enzyme which asist in hydrolysis of glycosidic bond.	It is also a glucosidase enzyme which asist hydrolysis of glycosidic bond.
It acts on α-1,4 glycosidic bond and release glucose units.	It acts on α-1,6 glycosidic bond it releases monomer.

Long Answer Type Questions

Question 1.
Describe the physiology of digestion of different food stuffs in human digestive system.
Answer:
Digestion in Small Intestine:
To further facilitate the digestion of food, muscularis layer of small intestine starts peristaltic movements This allows a thorough mixing up of food with various secretions in the intestine.
These contractions of muscles in the small intestine allows the further churning and kneading of the chyme , and finally pushing it into the large intestine.

Segmented contracion of the wall of the small intestine

The respective digestive juices from the liver (bile), pancreas (pancreatic juice) and small intestine (intestinal juices) are released into the small intestine to bring out the further chemical simplification of food. The pancreatic juice from the pancreas and the bile from the liver are released through the hepatopancreatic duct.

Digestion in small intestine can be studied under two categories as follows
(a) Digestion in the Duodenum:
In the duodenum, the chyme is mixed with three alkaline juices; bile from the liver, pancreatic juice from the pancreas, and intestinal juice from intestinal glands (crypts of Lieberkuhn); and mucous from the Brunner’s glands. The enteroendocrine cells present in the mucosal layer of the duodenum are stimulated to secrete several gastro-intestinal hormones, when the acidified chyme of the stomach enters into it. Two such hormones bearing significant roles in the release of digestive juices are Cholecystokinin-Pancreozymin (CCK-PZ) and Secretin.

(i) Cholecystokinin-Pancreozymin (CCK-PZ) It is a single hormone possessing two activities. Cholecystokinin (CCK) activity stimulates the gall bladder to contract and release bile into the duodenum, while pancreozymin activity stimulates the acinar cells of the pancreas to secrete increasing amounts of pancreatic juice, rich in enzymes.

(ii) Secretin It stimulates the duct cells of the pancreatic acini to secrete sodium bicarbonate into the pancreatic juice and thus makes the pancreatic juice alkaline.

In addition, enterogastrone is presumed to be a separate, hormone regulating gastro-intestinal functions. However, it is not a separate entity, but rather a collection of two hormones, secretin and cholecystokinin-pancreozymin, which inhibit gastric function.

Action of Panacreatic Juice:
The pancreatic juice secreted from the pancreas contains the various inactive enzymes.
These are as follows
(a) Trypsinogen
(b) Chymotrypsinogen
(c) Procarboxypeptidases
(d) Amylases
(e) Lipases
(f) Nucleases
Trypsinogen is activated by an enzyme enterokinase secreted by intestinal mucosa into active trypsin which in turn activates the other enzymes of pancreatic juice.

The proteins, proteases and peptones (partially hydrolysed form of proteins) present in the chyme (reaching the intestine) are acted upon by the proteolytic enzymes of pancreatic juice. These are given below as

* Carbohydrates in the chyme are hydrolysed by pancreatic amylase into disaccharides.

Nucleases in the pancreatic juice acts on nucleic acids to form nucleotides and nucleosides.

The bile secreted from the liver is released into duodenum of small intestine. Bile contains the bile pigments, i.e. bilirubin and biliverdin, bile salts, cholesterol and phospholipids.
Thus, fats are broken down into di and monoglycerides by the action of lipases secreted by pancreas.

Bile does not contain any enzyme as gastric juice. It helps in emulsifying fats, i.e. in breakdown of fats into very small micelles which are kept suspended in an aqueous medium.
The process of emulsification is basically carried out by the salts of bile. This increases the surface area of fat available for digestion by the lipase (as bile also activates lipases).

Question 2.
Draw a neat labelled diagram of human alimentary canal (Description is not required).
Answer:

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 15 Plant Growth and Development Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 15 Question Answer Plant Growth and Development

Plant Growth and Development Class 11 Questions and Answers CHSE Odisha

Very Short Answer Types Questions

Multiple choices questions

Question 1.
Gibberellic acids show which of the following physiological effects:
(a) yellowing of young leaves
(b) elongation of genetically dwarf plants
(c) shortening of genetically tall plants
(d) yellowing of old leaves
Answer:
(b) elongation of genetically dwarf plants

Question 2.
What will happen when the dark period of short day plants is interrupted by a flash of light?
(a) flower immediately
(b) will not flower
(c) induce more flowering
(d) converts to a long day plant
Answer:
(b) will not flower

Question 3.
The plant hormone connected primarily with cell division is
(a) IAA
(b) NAA
(c) Kinetin
(d) GA
Answer:
(c) Kinetin

Question 4.
Apical dominance is influenced by
(a) GA
(b) Ethylene
(c) Auxin
(d) Coumarine
Answer:
(c) Auxin

Question 5.
Abscisic acid causes
(a) stomatal closure
(b) leaf expansion
(c) root formation
(d) stem elongation
Answer:
(a) stomatal closure

Question 6.
Richmond-Lang effect is due to
(a) auxin
(b) abscisic acid
(c) cytokinin
(d) ethylene
Answer:
(c) cytokinin

Question 7.
Auxin transport is
(a) polar
(b) non-polar
(c) symplastic
(d) apoplastic
Answer:
(a) polar

Fill in the blanks

Question 1.
Fruit ripening is induced by the hormone ……….. .
Answer:
ethylene

Question 2.
Mangrove plants generally show …………. type of germination.
Answer:
viviparous

Question 3.
Florigen is associated with …………. .
Answer:
flowering

Question 4.
The amino acid ………….. is the precursor of ethylene.
Answer:
methionine

Short Answer Type Questions

Question 1.
Apical dominance
Answer:
Auxins perform several functions, these are as follows
(i) Apical Dominance Presence of auxin in higher , concentration (in higher plants) in shoot apex, promotes apical dominance. It is seen commonly in many vascular plants, that presence of apical buds does not allow the lateral buds to grow. They only start developing into branches when the apical bud is removed.

Apical dominance in plants (a) A plant with apical bud intact (b) A plant with apical bud removed

(ii) Initiation of Roots In contrast to stem, higher concentration of auxin inhibits the elongation of shoots, but it initiates more lateral branches of roots.

(iii) Inhibition of Abscission Natural auxins delay abscission of young fruits and leaves and also used to control pre-harvest fruit drop.

(iv) Cell Elongation Auxin stimulates the elongation of cells of shoots.

(v) Promotes Flowering Presence of auxin helps in promoting flowering in some plants, e.g., pineapple, litchi, etc.

(vi) Metabolism Application of auxin can enhance metabolism due to mobilisation of nutrients and growth promoting substances.

Question 2.
Seed dormancy
Answer:
In majority of angiospermic plants, seeds remain in an inactive state and germinate only after a specific period of rest or dormancy.
Thus, dormancy may be defined as, ‘the inactive state of the seed in which growth of the embryo is temporarily suspended for a specific length of time’.
This state of inactivation may be due to some internal factors that inhibit the process of germination. The period of dormancy varies in all the plants.
On the contrary, cereals germinate immediately after harvest and seeds of citrus germinate in situ.

Question 3.
Vernalisation
Answer:
Beside light, the temperature also affects the flowering and other vital phenomenon of plants. It has been observed that there are some plants which do not flower until they are not exposed to low temperature, i.e., thdy depend either qualitatively or quantitatively on exposure to low temperature to flower.

This chilling requirement of the plants for flowering is known as vernalisation. It prevents the precocious reproductive development late in the growing season, enabling plant to have sufficient time to reach the level of maturity.

Long Answer Type Questions

Question 1.
Describe the different types of seed germination.
Answer:
Seed Germination
It is the process by which the dormant embryo of the seed resumes active growth and forms a seedling. It is an irreversible process during which radicle grows out first to establish root. After that, plumule grows to form shoot.
Germination may be of three types

(i) Epigeal Germination
In this type of germination, cotyledons are pushed out of the soil. The cotyledons become green and also perform photosynthesis in addition to food storage.

In dicots, this happens due to the elongation of hypocotyl (stem of germinating seedling between cotyledons and radicle), e.g. bean, castor, mustard, tamarind, sunflower, etc.

Epigeal germination

(ii) Hypogeal Germination
In this type of germination, the cotyledons do not come out of the soil and remain underground. The epicotyl (part of embryonic axis between plumule and cotyledons) elongates first to raise the first leaves out of the soil. The hypocotyl growth is restricted, e.g. all monocots (e.g. rice, maize, wheat, etc) and dicots such as gram, pea, mango, groundnut, etc.

Hypogeal Germination of gram

(iii) Viviparous Germination
It is a special type of germination found growing-in salty lakes, sea coasts and deltas, i.e. in mangrove plants.

Germination in vivipary plants

In this process, seed germinates while still attached to the parent plant.
The radicle elongates considerably and projects out of the fruit while its lower part becomes thick and swollen. Finally, the seedling breaks of the parent plant due to its increasing weight and gets embedded in the muddy soil below.
The lateral roots develop soon at the basal end of the radicle.
It is also called aerial germination, e.g. Rhizophora, Ceriops, Avicennia, etc.

Factors Affecting Seed Germination:
Seed germination is directly affected by various factors. These are as follow:
1. Water
It is very essential as seed cannot germinate unless sufficient amount of water is available. Water is important because

• It activates the enzymes which digest the complex reserve food of the seed.
• It maintains the turgidity of the embryonal cells and helps in cell elongation.
• It helps in the rupturing of the seed coat.
• It is the medium for all physiological processes.

2. Oxygen
It is needed in sufficient quantity for germination.
The seed is activated on absorbing water and carries an aerobic respiration at a higher rate, so a lot of O₂ is consumed. Thus, O₂ is essential for respiration and all other physiological activities.

3. Temperature
Suitable temperature is a necessity for germination as a number of physiological processes occur within seed.
The range of optimum temperature varies greatly in different types of seeds. However, most of the seeds fail to germinate below 0°C and above 50°C. The optimum temperature is 25-30°C in most plants.

4. Light
Most of the plants do not require light for germination. Thus, it is not considered as an essential factor. The effect of light on different seeds led to their categorisation into the three groups as given below:

• Positively Photoblastic These seeds require light for germination, e.g. lettuce.
• Negatively Photoblastic These seeds do not require light for germination (i.e. total darkness is needed). If kept under lighted conditions, they do not germinate, e.g. pumpkin.
• Photoblastic Neutral These seeds germinate equally well under dark as well as in light conditions, e.g. cultivated plants like cucumber, tomato, etc.

Question 2.
Give an account of physiological effects of auxins in plants.
Answer:
Auxins
Auxin (Gk. auxein to grow) was initially isolated from the urine of human, but later on, their presence was also found in plants and was proved to be the first PGR ever known. The real plant auxin is chemically known as Indole -3-Acetic Acid (IAA). The term is also applied to other natural and synthetic compounds having various growth regulating properties. Production of auxin generally takes place in the region of growing apices of the stems and roots from where they migrate to the site of their action.

Note Auxins can move only through cell to cell by diffusion, i.e., they cannot move through vascular tissues.

Types of Auxins:
There are generally two basic categories in which auxins are divided
(i) Natural Auxins
It occurs naturally in plants and fungi, e.g., Indole Acetic Acid (IAA) and Indole Butyric Acid (IBA).

(ii) Synthetic Auxins
These are prepared from synthetic compounds that cause several responses to IAA. They can easily move in all directions inside the plants, e.g., Naphthalene Acetic Acid (NAA), 2, 4- dichlorophenoxyacetic acid (2, 4-D).
All these types of auxins are extensively been used in agricultural and horticultural practices.

Functions of Auxins:
Auxins perform several functions, these are as follows
(i) Apical Dominance Presence of auxin in higher , concentration (in higher plants) in shoot apex, promotes apical dominance. It is seen commonly in many vascular plants, that presence of apical buds does not allow the lateral buds to grow. They only start developing into branches when the apical bud is removed.

Apical dominance in plants (a) A plant with apical bud intact (b) A plant with apical bud removed

(ii) Initiation of Roots In contrast to stem, higher concentration of auxin inhibits the elongation of shoots, but it initiates more lateral branches of roots.

(iii) Inhibition of Abscission Natural auxins delay abscission of young fruits and leaves and also used to control pre-harvest fruit drop.

(iv) Cell Elongation Auxin stimulates the elongation of cells of shoots.

(v) Promotes Flowering Presence of auxin helps in promoting flowering in some plants, e.g., pineapple, litchi, etc.

(vi) Metabolism Application of auxin can enhance metabolism due to mobilisation of nutrients and growth promoting substances.

Applications of Auxins:
As stated, use of synthetic auxins is widely accepted now-a-days in various agricultural and horticultural practices.
Following are the applications of auxins

1. Eradication of Weeds Auxins are used as weedicides and herbicides. Application of 2, 4-dichlorophenoxyacetic acid (2, 4-D) is widely done in order to kill dicotyledonous weeds. It does not affect mature, monocotyledonous plants.
2. Parthenocarpy Auxins are sprayed on to the unpollinated pistil and make them develop into parthenocarpic fruits, which carry a better market values.

Question 3.
Discuss the physiological effects of gibberellings in plants.
Answer:
Gibberellins:
These are another group of plant growth regulators, which are known to be weakly acidic growth hormones. There are more than 100 different gibberellins reported from widely different organisms like fungi and higher plants.

All of them are known to be acidic in nature, thus, they are termed as Gibberellic Acids (i.e., GA, GA₁, GA₂ and so on). However, GA₃ is the most important gibberellic acid which was first to be discovered. It is most extensively studied amongst all gibberellins.

Functions of Gibberellins:
Gibberellins show various important physiological effects

1. Elongation of Intemodes It helps in elongation of the internodes so as to increase the height of the plant. They cause an increase in length of axis and is also used in increasing length of grapes stalks.
2. Elongation of Genetically Dwarf Plants It has been seen that if gibberellins are administered to a dwarf plant (pea, maize, etc), it may help in overcoming dwarfism. It also causes fruits to elongate and improve their shape, e.g., in apples, etc.
3. Bolting The gibberellins also helps in promoting bolting (internode elongation) just prior to their reproductive phase or flowering. If gibberellin is sprayed on rosette plants like beet, cabbage as these plants will show extensive internodal growth and profuse leaf development.
4. Breaking Dormancy It also helps in overcoming natural dormancy in buds, tubers, seeds, etc., and helps them to grow.
   Seed is said to be in the dormant state when it remains dry and non-germinating even if all conditions for germination are available, Thus, by ‘breaking seed dormancy’, we simply mean, to induce the
   germination in seeds.
5. Flowering This can also be induced in long day plants by the action of gibberellins.

Applications of Gibberellins
Gibberellins, apart from showing,varied physiological effects, also have numerous applications.
These are as follows

1. Delays Senescence Gibberellins can delay the ripening of fruits such as in Citrus, apples, etc. This can also be used for safe and prolonged storage of the fruits.
2. Malting Process The process of malting in brewing industry can be speeded up by the use of GA₃.
3. Sugar Yield As carbohydrate is stored in the form of sugar in the stems of sugarcane. Thus, if crop of sugarcane is sprayed with gibberellins. It results in increased internodal length of the stem. This, enhances the increase in the yield of sugarcane as much as 20 tonnes per acre.
4. Early Seed Production When sprayed on juvenille conifers, like Cycas and Pinus gibberellins hasten the maturity period of them leading to early seed production.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 14 Respiration Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 14 Question Answer Respiration

Respiration Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Multiple choice questions:

Question 1.
The first reaction step in glycolysis, that produces ATP, is catalysed by the enzyme
(a) Hexaokinase
(b) Pyruvate kinase
(c) Phosphoglycerate kinase
(d) Phosphofructokinase
Answer:
(d) Phosphofructokinase

Question 2.
The reaction which links glycolysis with Krebs cycle is catalysed by
(a) Glutamate dehydrogenase
(b) Pyruvate dehydrogenase complex
(c) Citralilyase
(d) Pyruvate kinase
Answer:
(b) Pyruvate dehydrogenase complex

Question 3.
Which of the following respiratory substrates produces per mole the highest number of ATP molecules?
(a) Glucose
(b) Sucrose
(c) Strach
(d) Fatty acid
Answer:
(a) Glucose

Question 4.
The enzyme which splits 6-C compound to 3-C compound during glucolysis is
(a) fumarase
(b) aldolase
(c) ligase
(d) carboxylase.
Answer:
(b) aldolase

Question 5.
Glycolysis takes place in
(a) nucleus
(b) vacuole
(c) cytoplasm
(d) mitochondria
Answer:
(c) cytoplasm

Question 6.
The respiratory quotient, when carbohydrates are used as respiratory substrate, is
(a) 1.0
(b) 0.7
(c) 0.9
(d) 0.3
Answer:
(a) 1.0

Fill in the blanks:

Question 1.
Anaerobic respiration is often known as ……………. .
Answer:
Fermentation

Question 2.
The synthesis of ATP involving the direct transfer of phosphate group from a substrate molecule to ADP is called as ……………. .
Answer:
Substrate level phosphorylation

Question 3.
The formation of ethanol from pyrurate is catalysed by the enzymes ………… and alcohol dehydrogenase.
Answer:
Pyruvate decarboxylase

Question 4.
The reactions of Krebs cycle takes place inside …………… .
Answer:
Mitochondrial matrix

Short Answer Type Questions

Question 1.
Alcoholic fermentation.
Answer:
It occurs in fungi and some higher plants. The incomplete oxidation of glucose is achieved under anaerobic condition by a series of reactions in which pyruvic acid is converted to CO₂ and ethonol

Question 2.
Lactic acid fermentation
Answer:
It occurs in human’s muscles, bacteria, etc. Lactic acid is produced as an end product during the reduction of pyruvate by NADH₂ is oxidised to NAD⁺. This reaction is catalysed by lactic acid dehydrogenase, FMN proteins and Zn²⁺ions.

Question 3.
Substrate level phosphorylation
Answer:
The type of ATP synthesis involving the direct transfer of phosphate group from a substrate molecule to ADP to form ATP is called substrate level phosphorylation. It takes place during the following reactions
(i) When 1,3 bisphosphoglycerate is converted to 3-phosphoglycerate.
(ii) When phosphoenol pyruvate is converted to pyruvic acid.

Question 4.
Chemiosmotic hypothesis
Answer:
It was explained by Peter Mitchell in 1961 for which he was awarded the Noble prize in chemistry in 1978. It explains the molecular mechanism of ATP synthesis by suggesting that, the action of ATP synthase is coupled with proton gradient. It is the action of proton gradient that causes a proton motive force. This force allows ATP synthase to phosphorylate ADP and inorganic phosphate to ATP.

Question 5.
Respiratorory Quotient
Answer:
During aerobic respiration, O₂ is consumed and CO₂ is released. The ratio of the amount of CO₂ evolved to the amount of O₂ consumed in respiration is called respiratory quotient (RQ)

Amount of 02 consumed
The value of RQ depends upon the type of substrate used for respiration
RQ value of different substrates is as follows:
RQ = 1 for carbohydrates
RQ < 1 for fats = 0.7
RQ < 1 for proteins = 0.8 – 0.9

Question 6.
Oxidative phosphorylation.
Answer:
The formation of ATP molecules coupled to the transfer of electrons derived from the oxidation of organic compounds through the mitochondrial electron transport chain is called oxidative phosphorylation.

Long Answer Type Questions

Question 1.
Describe the reaction steps of glycolysis
Answer:
Glycolysis:
Glycolysis (Gr. Glycos-sugar, lysis-splitting), is a stepwise process by which one molecule of glucose (6C) breaks down into two molecules of pyruvic acid (3C).

The scheme of glycolysis was given by Gustav Embden, Otto Meyerhof and J Parnas and is often referred as the EMP pathway. It is a common pathway in both aerobic and anaerobic modes of respiration. But in case of anaerobic organisms, it is the only process of respiration. Glycolysis occurs in the cytoplasm of the cell. During the process glucose gets partially oxidised. In plants, this glucose is derived from sucrose (end product of photosynthesis) or from storage carbohydrates.

During the course of process in plant sucrose is first converted into glucose and fructose by the action of invertase enzyme, after this, these two monosaccharides enter the glycolytic pathway.

Steps Involved in Glycolysis:
In glycolysis, a chain of 10 reactions, occur under the control of different enzymes. These reactions can be categorised in to preparatory (or investment) phase and pay off (energy conserving) phase.
It involves the following steps

Step I Phosphorylation of glucose occurs under the action of an enzyme hexokinase and Mg²⁺ that gives rise to glucose-6-phosphate by the utilisation of ATP.

Step II Isomerisation of this phosphorylated glucose-6-phosphate takes place to form fructose-6-phosphate with the help of an enzyme phosphohexose isomerase (reversible reaction).

Step III This fructose-6-phosphate is again phosphorylated by ATP in order to form fructose 1, 6-bisphosphate in the presence of an enzyme phosphofructokinase and Mg²⁺.
The steps of phosphorylation of glucose to fructose 1, 6-bisphosphate (i.e. from step 1 to 3) activates the sugar thus, preventing it from . getting out of the cell.

Step IV Splitting of fructose 1, 6-bisphosphate takes place into two triose phosphate molecules, i.e. dihydroxyacetone 3-phosphate and 3-phosphoglyceraldehyde (i.e. PGAL). This reaction is catalysed by an enzyme aldolase.

Step V Each molecule of PGAL removes two redox equivalents in the form of hydrogen atom and transfer them to a molecule of NAD⁺ (This NAD⁺ forms NADH + H⁺) and accepts inorganic phosphate (Pi) from phosphoric acid. This reaction in turn leads to the conversion to PGAL (which gets oxidised) to 1, 3-bisphosphoglycerate (BPGA) (reversible reaction).

Step VI 1, 3-bisphosphoglycerate is converted to 3-phosphoglycerate with the formation of ATP.
This reaction is catalysed by an enzyme phosphoglycerate kinase. It is also known as energy yielding process. The formation of ATP directly from metabolites constitutes substrate level phosphorylation (reversible reaction).

Step VII In this step, 3-phosphoglycerate is subsequendy isomerised to form 2-phosphoglycerate, catalysed by enzyme phosphoglyceromutase (reversible reaction).

Step VIII In the presence of enzyme enolase and Mg²⁺, with the loss of a water molecule, 2-phosphoglycerate is converted into Phosphoenol Pyruvate (PEP) (reversible reaction).

Step IX High energy phosphate group of Phosphoenol Pyruvate (PEP) is transferred to a molecule of ADP, by the action of enzyme pyruvate kinase in the presence of Mg²⁺ and K⁺. This in turn produces two molecules of pyruvic acid (pyruvate) and a molecule of ATP by substrate level phosphorylation. The pyruvic acid thus, produced is the key product of glycolysis.

Question 2.
Describe the metabolic fate of pyruvate.
Answer:
Metabolic Fate of Pyruvate:
Pyruvate is the end product of glycolysis. The sequence of reactions leading to the formation of pyruvate from glucose is the common pathway occurring during anaerobic and aerobic respiration. Depending upon the absence or presence of molecular oxygen and the cellular metabolic need, Pyruvate takes up different routes for its metabolism

Metabolic fate of pyruvate under aerobic and anaerobic conditions

In the absence of molecular oxygen, respiratory electron transport chain and oxidative phosphorylation can not function in the mitochondrion because molecular oxygen is the terminal electron acceptor for these two highly coordinated processes. As a result the oxidation of NADH to form NAD does not take place. NAD is available in limited amount in the cell. When whole NAD becomes reduced to NADH in the presence of NAD dependent glyceraldehyde 3-phosphate dehydrogenase, glycolysis can not continue to operate. Under the situation of unavailability of molecular oxygen,glycolysis is the main source of chemical energy (ATP) necessary for cell .survival.

Hence, NAD is required to regenerate or to proceed the glycolysis process. Different organisms and cell type can metabolise pyruvate by fermentation also.

Various microorganisms, bacteria, animals and plants are known to catabolise pyruvic acid into various organic compounds depending upon the specific enzymes they possess.

Some of these types are as follows
(i) During alcoholic fermentation, in fungi (e.g., yeast), and some higher plants, the incomplete oxidation of glucose is achieved under anaerobic condition-by a series of reactions in which pyruvic acid is converted to CO₂ and ethanol.
It is done under two steps
(a) Pyruvic acid is first decarboxylated to acetaldehyde formed in the presence of enzyme pyruvic acid decarboxylase.
CH₃CCOOH → CH₃CHO (Acetaldehyde) + CO₂

(b) This acetaldehyde is further reduced to ethyl alcohol or ethanol in the presence of enzyme, i.e. alcohol dehydrogenase.
CH₃CHO + NADH + H² → C₂H₅OH (Ethanol) + NAD⁺

(ii) During lactic acid fermentation occuring in muscles, organisms like some bacteria produce lactic acid as an end product from pyruvic acid.
During the reduction, the pyruvic acid produced in glycolysis is reduced by NADH₂ to form lactic acid, CO₂ is not produced and NADH₂ is oxidised to NAD⁺. This reaction is catalysed by a lactic acid dehydrogenase, FMN proteins and Zn²⁺ ions.

Major pathways of anaerobic respiration

Likewise, in case of animal cells also (such as muscles) during exercise, when there is inadequate amount of oxygen for cellular respiration, pyruvic acid is reduced to lactic acid in the presence of enzyme lactate dehydrogenase. Thus, in both the processes oxidation of reducing (NADH + H⁺) agent takes place.

Energy Yield in Fermentation:
In both alcoholic and lactic acid fermentation, the energy released is very less, i.e. not more than 7% of the energy is released from glucose and not all of it is trapped as high energy bonds of ATP.
Also, the fermentation processes are proved to be hazardous in nature because either acid or alcohol is produced on oxidation. Apart from this, yeasts may also poison themselves to death if the concentration of alcohol reaches about 13%.

Question 3.
Describe the reaction steps of Krebs cycle.
Answer:
Output of Krebs’ Cycle or Citric Acid Cycle:
During this cycle of reactions, 3 molecules of NAD⁺ are reduced to NADH + H⁺ , and one molecule of FAD⁺ is reduced to FADH₂. And also one molecule of ATP is reduced directly from GTP (by substrate level phosphorylation). For continuous oxidation of acetyl . Co-A, continued replenishment of oxaloacetic acid is necessary. In addition to this, regeneration of NAD⁺ and FAD⁺ from NADH and FADH₂, respectively are also required.
The summary equation for this phase of respiration is as follows

Till now, glucose has been broken down to release C02 and 8 molecules of NADH + H⁺, 2 FADH₂ are synthesised and just 2 molecules of ATP.

Importance of Citric Acid Cycle:
The citric acid cycle is important in the following ways
(i) This is the major pathway for the formation for ATP molecules.
(ii) Many intermediate compounds of this cycle are used in the synthesis of other biomolecules.

Question 4.
Describe the respiratory electron transport chain and explain the mechanism of ATP synthesis.
Answer:
Electron Transport System (ETS):
Electron Transport System (ETS) is the metabolic pathway through which the electron passes from one carrier to another. It occurs in the inner mitochondrial membrane.

Electron Transport System (ETS)

The electron transport system consists of four enzyme complexes, which are arranged in a series on the inner membrane of the mitochondria.
(i) Electrons from NADH produced in citric acid cycle are oxidised by NADH dehydrogenase (complex I) and are transferred to ubiquinone located within the inner membrane of the mitochondria.

(ii) Reducing equivalents are also received by ubiquinone via FADH₂ (complex II), generated during the oxidation of succinate in the citric acid cycle. This reduced ubiquinone (ubiquinol) is then oxidised with the electron transfer to cytochrome-c (small protein attached to the outer surface of the inner membrane). Now, via cytochrome-b, c₁ complex (complex III) cytochrome, acts as a mobile carrier for transfer of electrons between complex III and IV.

(iii) The (complex IV), known as cytochrome-c oxidase complex contains cytochromes-a, a₃ and two copper centres).

During the course of transfer, when’electrons pass from one carrier molecule to another (via complex I to IV) in the electron transport chain, they get coupled to ATP synthase (i.e. complex V) for the production of ATP from ADP and inorganic phosphate. The number of • ATP molecules synthesised depends on the nature of the electron donor.

One molecule of NADH on oxidation provides 3 molecules of ATP while one FADH₂ produces 2 molecules of ATP, because its redox potential is higher than NADH and thus, enters the ETS after bypassing the first site of phosphorylation. The electrons are finally accepted by oxygen having the highest redox potential in the series which along with H⁺ forms water.

Aerobic process of respiration takes place only in the presence of O₂, the role of O₂ is limited at the terminal stage of the process. Yet, the presence of oxygen is vital because it drives the whole process by removing hydrogen from the system.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 13 Photosynthesis in Higher Plants Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 13 Question Answer Photosynthesis in Higher Plants

Photosynthesis in Higher Plants Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Multiple Choices Questions

Question 1.
Oxygenic photosynthesis does not occurs in
(a) plants
(b) green sulphur bacteria
(c) bryophytes
(d) cyanobacteria
Answer:
(b) green sulphur bacteria

Question 2.
Cyclic electron transfer around PS-I results in the formation of
(a) ATP
(b) NADPH
(c) ATP and NADPH
(d) ATP, NADPH and O₂
Answer:
(a) ATP

Question 3.
In higher plant chloroplasts, the chlorophylls are located in
(a) stroma
(b) lumen of grana
(c) outer membrane
(d) thylakoid membrane
Answer:
(d) thylakoid membrane

Question 4.
All algae generally have
(a) chlorophyll-a and chlorophyll-b
(b) chlorophyll-a and ß-carotene
(c) chlorophyll-b and ß-carotene
(d) phycoerythrin and ß-carotene
Answer:
(a) chlorophyll-a and chlorophyll-b

Question 5.
In C₄ -plants, the first stable product of CO₂-fixation in mesophyll cells is
(a) 3-phosphoglycerate
(b) dihydroxyacetonephosphate
(c) oxaloacetate
(d) phosphoenol pyruvate
Answer:
(c) oxaloacetate

Question 6.
During light absorption and emission by chlorophyll molecule, the length of fluroscent light is
(a) longer than that of absorbed light
(b) shorter than that of absorbed light
(c) equal to that absorbed light
(d) equal to that of phosphorescent light
Answer:
(a) longer than that of absorbed light

Question 7.
Electron donor to PS-I is
(a) cyt-b
(b) cyt-b₆
(c) ferredoxin
(d) plastocyanin
Answer:
(d) plastocyanin

Question 8.
The reaction centre of PS-II is:
(a) P₆₀₀
(b) P₆₈₀
(c) P₇₀₀
(d) P₇₅₀
Answer:
(b) P₆₈₀

Question 9.
The ions essential for photolysis of water during photosynthesis are
(a) Mn⁺⁺, Ca⁺⁺ and Cl^–
(b) Mg⁺⁺, Ca⁺⁺ and Cl^–
(c) Cu⁺⁺, Ca⁺⁺ and Mg⁺⁺
(d) Fe⁺⁺, Ca⁺⁺ and Mn⁺⁺
Answer:
(a) Mn⁺⁺, Ca⁺⁺ and Cl^–

Question 10.
The fist reaction of photosynthesis is
(a) excitation of chlorophyll
(b) photolysis of water
(c) ATP formation
(d) CO₂-fixation
Answer:
(a) excitation of chlorophyll

Fill in the blanks

Question 1.
The graph showing the effectiveness of different wave lengths of light on the photosynthetic activity of leaves is known as …………… .
Answer:
Action spectrum

Question 2.
In higher plants the reaction centre chlorophyll of PS-I is …………. .
Answer:
P₇₀₀

Question 3.
In C4-plants Rubisco is present is the chloroplasts of ………….. cells.
Answer:
Spongy

Question 4.
The accepter of CO₂ during photosynthesis in bundle sheath cells of C4-plants is …………….. .
Answer:
RuBP. (Ribulose-1, 5 biphosphate)

Question 5.
Kranz type of leaf anatomy is seen in ………….. plants.
Answer:
C₄

Short Answer Type Questions

Question 1.
Absorption spectrum
It is the curve that shows the amount of different wavelength of lights absorbed by a substance (photosynthetic pigment). The graph given below shows the ability of chlorophyll-a to absorb lights of different wavelengths.
Chlorophyll-a shows the maximum absorption peak at 450 nm and also shows another peak at 650 nm.

Graph showing the absorption spectrum, of chlorophyll-a, b, and the carotenoids

Question 2.
Photosystem
Answer:
During the course of light reaction, light is absorbed by photosynthetic pigments present in the quantasomes of grana thylakoids.
These photosynthetic pigments are organised into two discrete photochemical Light Harvesting Complexes (LHCs) known as Photosystem-I (PS-I) and Photosystem-II (PS-II).
The light harvesting complexes or photosystems are made up of hundreds of pigment molecules bounded by proteins. Each photosystem has a photocentre or reaction centre, where actual reaction takes place.

Question 3.
Photolysis of water
Answer:
The electrons are continuously supplied to the photosystems-II by the available electrons, which get replaced due to the splitting of water.
In this process, the water splits into protons, electrons and oxygen. The complex for water splitting is associated with the photosystems-II that is located on the inner side of the thylakoid membrane. Mn+ and Cl- ions also play important role in the photolysis of water molecule. These electrons thus, obtained by the splitting of water are needed to replace those electrons which are removed from the photosytems-I thus, are provided by photosystem-II.
2H₂O → 4H⁺ + O₂ ↑ + 4e^–
While all the electrons formed, are replaced, the protons get accumulated in the lumen of the thylakoid and the oxygen is evolved into the atmosphere.

Question 4.
Photophosphorylation
Answer:
Phosphorylation is the process through which, ATP is synthesised from ADP and inorganic phosphate (P) by the cell organelles (like mitochondria and chloroplasts). When it occurs in the presence of sunlight in chloroplast, it is called photophosphorylation.

Phosphorylation in mitochondria is not light dependent, but it uses the energy by oxidation of nutrients to produce ATP, hence it is called oxidative phosphorylation.

Question 5.
Photorespiration
Answer:
It is a light dependent cyclic process of oxygenation of RuBP and release of carbon dioxide by the photosynthetic organs of a plant. The site of photorespiration is chloroplast. Mitochondria and peroxisome are also required for completing the process. RuBP carboxylase, oxygenase is the main enzyme of dark reaction. It also catalyses another reactions that interferes with the functioning of Calvin cycle. It has active site for both, i.e. CO₂ and O₂.

The relative concentration of CO₂ and O₂ determines which of the two will bind to the enzyme.
Under the conditions, when O₂ concentration is more in atmosphere than CO₂, C₃-plants, RuBisCO acts as oxygenase enzyme and CO₂-fixation does not lead to PGA formation. Instead phosphoglycerate and phosphoglycolate are formed and photorespiration occurs.

Question 6.
CAM plants
Answer:
Some plants belonging to family-Crassulaceae have special kind of adaptation for performing photosynthesis. These are succulent photosynthetic xerophytic plants. These plants keep their stomata open during night and fix CO₂ in the night and use it in the day time. This is a xerophytic adaptation of plants to reduce transpiration rate by keeping stomata shut during day time. The events of this process are summarised in the flow chart given below

Long Answer Type Questions

Question 1.
Describe the light reaction of photosynthesis.
Answer:
5 Light Reaction (The Photochemical Phase)
Light reaction includes the following steps, i.e. absorption of light, splitting of water, release of oxygen and finally the formation of high energy chemical intermediates, i.e. ATP and NADPH.

Light Absorption
During the course of light reaction, light is absorbed by photosynthetic pigments present in the quantasomes of grana thylakoids.
These photosynthetic pigments are organised into two discrete photochemical Light Harvesting Complexes (LHCs) known as Photosystem-I (PS-I) and Photosystem-II (PS-II).

The light harvesting complexes or photosystems are made up of hundreds of pigment molecules bounded by proteins. Each photosystem has a photocentre or reaction centre, where actual reaction takes place.

This reaction centre contains a special chlorophyll-a molecule. It is fed by hundred other pigment molecules and it forms the light harvesting system called antennae. These antennae molecule absorb light of different wavelength, but shorter than reaction centre in order to make photosynthesis more efficient.

The light harvasting complex

The reaction centre is different in both the photosystem as given below
(i) In PS-I, the reaction centre or chlorophyll-a has peak of absorption at 700 nm, known as P₇₀₀.
(ii) In PS-II, the reaction centre has absorption peak at 680 nm hence, called P₆₈₀.

Question 2.
Explain different phases of Calvin cycle.
Answer:
The C₃ Cycle
This is a cyclic biochemical pathway of reduction of CO₂ or photosynthetic carbon, which was discovered by Calvin.
The Calvin cycle runs in all photosynthetic plants, no matter they show C₃, C₄ or any other pathway. It occurs in stroma of the chloroplast.

Primary Acceptor of CO₂ in C₃ Pathway
After a long research and conducting many experiments it was concluded by the scientists that in C₃ pathway, the acceptor molecule is a 5-carbon ketose sugar, i.e. Ribulose 5-Bisphosphate (5 RuBP). Calvin or C₃ cycle has many steps which are known as glycotic reversal or formation of sugar and takes place between reduction and regeneration. There are three major steps as follows

1. Carboxylation
It is the most crucial step of the Calvin cycle. In this fixation of CO₂ molecule takes place in the form of carboxylation of RuBP(5C). This reaction is catalysed by the enzyme RuBP carboxyase. This finally leads to the formation of two molecules of 3 Phosphoglyceric Acid (3PGA). As the RuBP carboxylase enzyme also has an activity of oxygenation. Thus, it is more commonly known as RuBP carboxylase-oxygenase or RuBisCO.
Img 5
Diagrammatic representation of Calvin cycle, regeneration of RuBP is indicated by broken lines

2. Reduction
After the carboxylation reaction, reduction of PGA takes place through a series of reactions leading to the formation of glucose.
In this step, the ATP (as energy source) and NADPH (hydrogen atom carrier) are utilised.
It is to be noted that 2 molecules of ATP and 2 molecules of NADPH are utilised in this step for phosphorylation and for the reduction of CO₂, respectively.
Hence, the fixation of 6 molecules of CO₂ and 6 turns of the cycle are required in order to release one molecule of glucose from the pathway.

3. Regeneration
For the continuous and uninterrupted functioning of the Calvin cycle, there must be a regular supply of ATP, NADPH and also sufficient amount of RuBP is required. The regeneration of RuBP (CO₂ acceptor) is a complex process and involves many types of sugar starting from triose (3C) to heptose (7C).
The regeneration step requires one ATP molecule for phosphorylation. Hence, for every CO₂ molecule that enters the Calvin cycle are required 3 molecules of ATP and 2 molecules of NADPH.

Thus, in order to produce one molecule of glucose through the Calvin pathway, 18 ATPs and 12 NADPHs are required.

Question 3.
Explain different phases of C4 pathway.
Answer:
The C₄ Pathway
It was worked out by two Australian scientists Hatch and Slack (1966). Thus, this is also known as Hatch and Slack pathway. C₄-plants are special as they have a special type of leaf anatomy that can tolerate high temperatures and show a response to high intensities. Inspite of having Oxaloacetic Acid (OAA) as their first CO₂ -fixation product, they use C₃ pathway or the Calvin cycle as the main photosynthetic pathway.

Note:

• Only angiospermic (no gymnosperm, bryophytes and pteridophytes, etc.) plants show this process to fix CO₂.
• The main aim of C₄-cycle is to fix very dilute solution of CO₂ (0.03% or 300 ppm) to concentrated CO₂ solution in bundle sheath cells to produce Oxaloacetic Acid (OAA).

Kranz Anatomy:
According to the structural leaf anatomy of C₃ and C₄-plants, the leaves of C₃-plants show only one type of cells called mesophyll cells, which contain only mesophyll chloroplast, while leaves of C₄-plants show two types of cells, i.e., outer mesophyll cells and inner spongy (which are large) cells around the vascular bundles called bundle sheath cells arranged in a circular manner.

It refers to the presence of two types of the chloroplast, in the leaves. The mesophyll cells contain well-developed granal chloroplast. They actively participate in light reaction. These produce ATP and NADPH₂.

The rudimentary chloroplasts are present in the cells of bundle sheath. They are agranal. The bundle sheath cells are mainly meant to carryout C₃ cycle.
This does not require well-developed chloroplast, so they are rudimentary lamellar type.

TS of maize leaf showing Kranz anatomy

The bundle sheath cells tend to form several layers around the vascular bundles.

They possess several special features such as

• Have large number of chloroplast.
• Thick walls which are impervious to gaseous exchange.
• There are no intercellular spaces.
  The Hatch and Slack pathway is also a cyclic process, which occurs in following steps

Step I: In C₄-plants, the initial fixation of CO₂ occurs in mesophyll cells. The primary acceptor of CO₂ is Phosphoenol Pyruvate (PEP).
Step II: It combines with CO₂ in the presence of an enzyme phosphoenol pyruvate carboxyfcise or PEP carboxylase (PEPcase) to form the first stable (or a 4 carbon organic acid) product of C₄ pathway, i.e. the Oxaloacetic Acid (OAA).
Step III: The compound (OAA) are transported to the bundle sheath cells where they are broken down, releasing CO₂ and a 3-carbon molecule.
Step IV: The 3-carbon compound is again transported back to the mesophyll cells where regeneration of PEP takes place, thus, completing the cycle.

Schematic representation of Hatch and Slack pathway

The CO₂ thus, released in the bundle sheath cells enters the C₃ or the Calvin cycle (common pathway to all plants).

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 12 Mineral Nutrition Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 12 Question Answer Mineral Nutrition

Mineral Nutrition Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Multiple Choices Questions

Question 1.
Most of the plants absorb nitrogen from soil in the form of.
(a) free N₂
(b) nitrites
(c) Nitrates
(d) NH₃
Answer:
(c) Nitrates

Question 2.
Choose the micro-nutrient
(a) Sulphur
(b) Manganese
(c) Calcium
(d) Nitrogen
Answer:
(b) Manganese

Question 3.
Choose the macronutrient
(a) Manganese
(b) Phosphorus
(c) Zinc
(d) Molybdanum
Answer:
(b) Phosphorus

Question 4.
Symbiotic nitrogen fixation is done by
(a) Rhizobium
(b) Clostridium
(c) Nostoc
(d) Azotobacter
Answer:
(a) Rhizobium

Question 5.
The enzyme responsible for nitrogen fixation requires.
(a) Fe and Mo
(b) Mo and Ca
(c) Zn and Cu
(d) Zn and Mn
Answer:
(a) Fe and Mo

Question 6.
Micro-organisms affect fertility of soil by
(a) Nitrogen-fixation
(b) Production of toxins
(c) Destroying harmful bacteria
(d) Retaining moisture
Answer:
(a) Nitrogen-fixation

Question 7.
Maintenance of soil fertility without addition of nutrients is due to
(a) activity of micro-organisms
(b) floods
(c) favourable temperature
(d) standing crops
Answer:
(a) activity of micro-organisms

Question 8.
The root nodules formed in the leguminous plant have a red pigment called
(a) Hemoglobin
(b) Phycocyanin
(c) Leghemoglobin
(d) Chlorophyll
Answer:
(c) Leghemoglobin

Question 9.
The process of conversion of ammonia into nitrate is called.
(a) Nitrification
(b) Ammonification
(c) Transcription
(d) Translation
Answer:
(a) Nitrification

Question 10.
The enzyme responsible for fixing nitrogen is called.
(a) Nitrate reductase
(b) Nitrite reductase
(c) Nitrogenase
(d) Aminoacid synthetase
Answer:
(c) Nitrogenase

Short Answer Type Questions

Write short notes on

Question 1.
Essential elements
Answer:
Essential. Mineral. Nutrients (Elements):
Essential elements are those elements which possess rhcir own structural or physiological properties and also without which the plants arc unable to complete their life cycle.
Plants has the ability to absorb most of the minerals present in the soil. More than sixty minerals present in soil have been recorded essential for plants our of the 105 discovered so far.

Question 2.
Hydroponics
Answer:
Hydroponics or Soilless Culture:
The technique of hydroponic was demonstrated by the experiment conducted by Julius Von Sach. It explains that the plants can be grown co their level of maturity in a well-defined nutrient solution even in the absence of soil.
Thus this technique of growing plant in a nutrient solution without soil is well-known and is also called water culture.

Question 3.
Biological nitrogen-fixation
Answer:
Biological Nitrogen-Fixation
The process in which atmospheric nitrogen gets converted into inorganic nitrogenous compounds (nitrate, nitrite and ammonia) by the involvement of microorganisms (bacteria, cyanobacteria, etc) is called biological nitrogen-fixation.
Very few organisms can utilise atmospheric nitrogen, only certain prokaryotes are capable of fixing nitrogen. The prokaryotic organism that reduces nitrogen has an enzyme called nitrogenase. Such microbes are called N₂ -fixers.
Img 1
Biological nitrogen-fixation may occur in asymbiotic as well as symbiotic manner.

Question 4.
Macronutrients
Answer:
Macronutrients
The elements that are generally found in plant tissues in large or excess amounts (around 10 m mole kg-1 or 10 mg per gram of dry matter) are called macronutrients or major elements. These elements are generally involved in the synthesis of organic molecules and development of osmotic potential. The list of macronutrients includes carbon, hydrogen, oxygen, nitrogen, phosphorus, sulphur, potassium, calcium and magnesium.
Out of all these elements, carbon, hydrogen and oxygen are obtained from CO₂ and H₂O while, the other elements are obtained from the soil itself.

Question 5.
Micronutrients
Answer:
Micronutrients:
The elements that are generally found in traces or very small amount only (i.e., less than 10 m mole kg-1 or less than 0.1 mg per gram of dry matter) are called micronutrients or minor elements. These are generally eight in number and the list includes iron, manganese, copper, molybdenum, zinc, boron, chlorine and nickel. These are mosdy involved in the functioning of enzymes as cofactors or activators of metals.

Question 6.
Asymbiotic nitrogen-fixation
Answer:
Asymbiotic Nitrogen-Fixation:
The fixation of N₂ by the microorganisms living freely, i.e. outside the plant cell is called asymbiotic or non-symbiotic biological nitrogen-fixation.
JE Carnahan in 1960 first reported the conversion of atmospheric nitrogen into ammonia by the asymbiotic or free-living nitrogen-fixing bacteria Clostridium pasteuriansums.

Question 7.
Symbiotic nitrogen-fixation
Answer:
It is the process of nitrogen-fixation with the help of symbiotic microorganisms. It involves a symbiotic relationship between plant and concerned microorganism. The process of symbiosis involves two organisms living together in different associations. Several types of biological nitrogen-fixing associations are known.
The most familiar one is the relationship of Rhizobium with the roots of several legumes belonging to class-Leguminosae like sweet pea, lentils, garden pea, alfalfa, sweet clover, broad bean, clover beans, etc.

Question 8.
Leghemoglobin
Answer:
Leghaemoglobin It is the red pigment found in the root nodules of leguminous plants. This reddish pigment is found in the cytoplasm of host cells. Leghaemoglobin combines with O₂ and helps to protect nitrogenase from O₂ damage. It also maintains steady supply of O₂ to nitrogen fixing bacteria for respiration. The ATP generated in this process of bacterial respiration is used for N₂-fixation.

Differentiate Between

Question 1.
Macro-elements and microelements.
Answer:
The differences between macronutrients and micronutrients

Macronutrients	Micronutrients
Their quantities can be easily detected in plants as they occur in large amounts.	Their quantities are not easily detectable. They occur in very^ small amounts in plants.
These are needed for growth, metabolism and other body functions.	These nutrients help in detoxifying the body and warding of harmful diseases.
Play significant role in the development of osmotic potential.	Do not have any role in osmotic potential.
Their higher concentration do not cause toxicity.	They cause toxicity even with slight increase from their , . maximal range.
Compounds of macronutrients contain calories.	Compounds of micronutrients do not contain calories.
Their required concentration is atleast 1 mg/g of dry matter.	Their required concentration is equal to or less than 0.1 mg/g of dry matter.
e.g., proteins, carbohydrates and fats.	e.g., vitamins and minerals.

Question 2.
Symbiotic and asymbiotic nitrogen-fixation.
Answer:
The differences between symbiotic and asymbiotic fixation

Symbiotic fixation	Asymbiotic fixation
Fixation of N<sub>2</sub> by symbiotic microorganisms.	Fixation of N<sub>2</sub> by free-living microorganisms.
Microorganisms involved are Clostridium, Azotobacter, etc.	Microorganism involved is Rhizobium.