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Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 3 Classification of Plant Kingdom Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 3 Question Answer Classification of Plant Kingdom

Classification of Plant Kingdom Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Multiple choice type questions

Question 1.
Green algae possess
(a) chlorophyll-a, b
(b) chlorophyll-a, c
(c) chlorophyll-a, carotenes
(d) chlorophyll-6, carotenes
Answer:
(a) chlorophyll-a, b

Question 2.
Agar is obtained from
(a) Gelidium
(b) Riccia
(c) Spirogyra
(d) Laminaria
Answer:
(a) Gelidium

Question 3.
Colour of brown algae is due to
(a) carotenoids
(b) phycoerythrin
(c) phycocyanin
(d) fucoxanthin
Answer:
(d) fucoxanthin

Question 4.
The largest alga out of four of the following
(a) Spirogyra
(b) Fucus
(c) macrocystis
(d) Sargassum
Answer:
(c) macrocystis

Question 5.
The land plants that lack vascular tissue.
(a) Bryophyta
(b) Angiosperm
(c) Pteridophyta
(d) Cycads
Answer:
(a) Bryophyta

Question 6.
Sporophyte is fully dependent and parasitic on gametophytic body in
(a) bryophytes
(b) gymnosperms
(c) monocots
(d) dicots
Answer:
(a) bryophytes

Question 7.
Seedless vascular plants are the
(a) liverworts
(b) mosses
(c) ferns
(d) monocots
Answer:
(c) ferns

Question 8.
Multicellular branched rhizoids and leafy gametophytes are found in
(a) all pteridophytes
(b) bryophytes
(c) some pteridophytes
(d) gymnosperms
Answer:
(b) bryophytes

Question 9.
Smallest angiosperm is
(a) Striga
(b) Wolfia
(c) Eucalyptus
(d) Nicotiana
Answer:
(b) Wolfia

Question 10.
Which of the following algae is very rich in proteins?
(a) Ulothrix
(b) Chlorella
(c) Gelidium
(d) Oscillatoria
Answer:
(b) Chlorella

Question 11.
A seed plant having a palm-like habit is
(a) Pinus
(b) Gnetum
(c) Cycas
(d) Ginkgo
Answer:
(c) Cycas

Question 12.
Gymnosperms are characterised by
(a) small leaves
(b) fruits
(c) naked ovules
(d) ciliated sperms
Answer:
(c) naked ovules

Question 13.
The thallus of Riccia is
(a) triploid
(b) haploid
(c) diploid
(d) polyploid
Answer:
(b) haploid

Question 14.
Peat is formed by
(a) Riccia
(b) Anthoceros
(c) Sphagnum
(d) Funaria
Answer:
(c) Sphagnum

Question 15.
The sporophyte consisting of foot, seta and capsule is seen in
(a) Riccia
(b) Cycas
(c) Selaginella
(d) Funaria
Answer:
(d) Funaria

Choose the correct answer from the words given in bracket

Question 1.
One of the following is a vascular cryptogam.
(Bryophytes, Pteridophytes, Gymnosperms, Angiosperms)
Answer:
Pteridophytes

Question 2.
One of the following features of gymnosperms is seen among lower group of plants.
(Seed, Ovule, Archegonium, Nucellus)
Answer:
Archegonium

Question 3.
Haplontic life cycle pattern is seen in one of the following plant groups.
(Algae, Angiosperms, Gymnosperms, Bryophytes)
Answer:
Algae

Question 4.
In which of the following zygote does not give rise to embryo?
(Pteridophyte, Gymnosperms, Algae, Angiosperms)
Answer:
Algae

Question 5.
One of the following is a naked seeded plant.
(Angiosperms, Gymnosperms, Bryophytes, Algae)
Answer:
Gymnosperms

Fill in the blanks

Question 1.
Bog moss is a common name of …………. .
Answer:
Sphagnum

Question 2
………….. is the tallest angiosperms.
Answer:
Eucalyptus

Question 3.
Ferns contain underground stem called …………. .
Answer:
Rhizome

Question 4.
In red algae the reserved food is …………. .
Answer:
Floridean starch

Question 5.
The gymnosperms are ………… seeded plants
Answer:
Naked

Question 6.
The angiosperms are ………. seeded plants.
Answer:
Enclosed

Question 7.
Spirally arranged …………… constitute a cone.
Answer:
Micro and megasporophylls

Question 8.
Production of spores of different sizes is called ………….. .
Answer:
Heterospory

Question 9.
There is a single cotyledon in the embryo of …………. class of angiosperms.
Answer:
Monocotyledonous

Question 10.
Gametophytes and sporophytes are independent of each other in …………… .
Answer:
Pteridophytes

Short Answer Types Questions

Question 1.
Write notes on (explain briefly the following terms)
(i) Heter-ospory
(ii) Archegonium
(iii) Antheridium
(iv) Haplontic
(v) Diplontic
(vi) Sporophyll
(vii) Embryo sac
(viii) Isogamy
(ix) Double fertilisation
(x) Triple fusion
(xi) Protonema
Answer:
(i) Heterospory Phenomenon of producing spores of two different sizes.

(ii) Archegonium It is the female sex organ in bryophytes. It is a flask-shaped structure consisting of a basal venter containing egg and upper slightly elongated neck.

(iii) Antheridium It is the male sex organ in bryophytes which produces biflagellate antherozoids.

(iv) The dominant photosynthetic phase is a gametophyte produced by haploid spores. The gametophyte produces gametes by mitosis. The gametes fuse and produce a diploid zygote, that represents sporophytic generation. There sporophytes are dependent on gametophyte. Meiosis in the zygote results in formation of haploid spores. This kind of life cycle is called haplontic. Many algae such as Volvox, Spirogyra and Chlamydonwnas represent this pattern of life cycle. Plant life cycle Haplontic.

(v) Diplontio In this type, the diploid sporophyte is dominant. The multicellular diploid phase is called sporophyte. The gametophytic phase is represented by the single to few-celled haploid gametophyte. This kind of life cycle is termed as diplontic. All seed bearing plants, gymnosperms and angiosperms follow this pattern of life cycle. Fucus, an alga is diplontic.

(vi) Sporophyll These are spore bearing leaves in pteridophytes. In some cases they form distinct structures called strobilus (e.g. Selaginella) or compact cone (e.g. Equisetum).

(vii) Embryo sac Haploid cell containing structure in angiosperms. It consists of
(i) a three-celled egg apparatus,
(ii) three antipodal cells and
(iii) two polar nuclei.

(viii) Isogamylt is the process of fusion of similar gametes.

(ix) Double fertilisation In angiosperms, one male gamete fuses with the egg cell called syngamy to form a diploid zygote and other fuses with diploid secondary nucleus to form a triploid Primary Endosperm Nucleus (PEN). Because there are two fusions, this event is called double fertilisation.

(x) Triple fusion In angiosperm one of the male gamete fuses with diploid secondary nucleus to produce triploid primary endosperm nucleus.

(xi) Protonema Creeping, green, branched and frequently filamentous stage in bryophytes.

Differentiate between

Question 1.
Red algae and Brown algae
Answer:

Classes	Phaeophyceae	Rhodophyceae
Common Name	Brown algae	Red algae
Major pigments	Chlorophyll-a, c, fucoxanthin	Chlorophyli-a, d, phycoerythrin
Stored Food	Mannitol, Laminarin	Floridean starch
Cell Wall	Cellulose and algin	Cellulose, pectin and poly sulphate esters
Flagellar Number and Position of Insertions	2, unequal, lateral	Absent
Habitat	Fresh water (rare) brackish water, salt water (most)	Freshwater (some) brackish water, salt water (most)

Question 2.
Liverworts and Moss
Answer:

Liverworts	Mosses
They are dorsiventral.	They have radial symmetry,
Plants are thalloid or foliose.	Mosses are foliose.
Midrib is not present in leaves.	Leaves have unbranched midrib.
Rhizoids are unicellular and unbranched.	Rhizoids are multicellular and branched.
Plants bear scales.	Scales are absent in plants.
A conducting strand is absent.	A conducting strand is commonly present.
Sporophyte is differentiated in foot, seta and capsule.	It is not differentiated in foot, seta and capsule.
Capsule often possesses elaters.	Elaters are absent.
Dehiscence occurs through elaters.	Peristome performs this function.
A protonema stage is absent.	A juvenile protonema stage is present.

Question 3.
Bryophytes and Pteridophytes
Answer:

Bryophytes	Pteridophytes
The main plant body is gametophyte.	It is sporophyte.
These are non-vascular plants.	These are vascular plants.
Sporophyte is parasitic over gametophyte.	Sporophyte is independent of gametophyte.
Plant body can be thalius or foliose.	It is differentiated into stem, leaves and roots.
True stems and leaves are not present.	It has true stems and leaves.
Roots are absent, rhizoids are present.	Roots are present.
Sex organs are stalked.	Sex organs are sessile.
The wall of archegonial neck is 5-6 rowed.	The wall of archegonial neck is 4-rowed.

Question 4.
Syngamy and Triple fusion
Answer:

Syngamy	Triple fusion
Fusion of male one gamete with the egg cell.	Fusion of the one male gamete with diploid secondary nucleus.
It results in the formation of zygote(2n).	It results in the formation of triploid Primary Endosperm Nucleus(PEN) (3n).

Question 5.
Monocots and Dicots
Answer:

Monocots	Dicots
They contain one cotyledon.	They contain two cotyledons.
Leaves have parallel venation.	Leaves have reticulate venation.
Fibrous root system is present.	Tap root system is present.
Stomata are dumb-bell-shaped.	Stomata are kidney- shaped.
Vascular bundles are scattered.	Vascular bundles are arranged in rings.
Cambium Is absent.	Cambium is present.
Stems do not have concentric arrangement of tissue. A ground tissue is present.	Stems have concentric arrangement of tissue epidermis cortex, endodermis, pericycie, pith, etc.
Secondary growth is absent with some exception in stems.	These show secondary growth in stem.
Root has pith in its centre.	Root is generally devoid of pith.
Secondary growth is absent in roots with some exceptions.	Secondary growth occurs in roots.

Question 6.
Algae and Fungi
Answer:

Algae	Fungi
They are autotrophic.	They are heterotrophic.
Most forms are aquatic.	Most forms are terrestrial.
Cell wall is made up of cellulose.	Cell wall is made up of chitin.
Contain starch as stored food material.	Contain glycogen and oils as stored food material.

Long Answer Type Questions

Question 1.
Describe the basis of classification and general characters of algae.
Answer:
Classification of Algae
Algae are divided into various classes based on pigmentation, type of stored food materials and kind of flagellation. The three main classes are Chlorophyceae, Phaeophyceae and Rhodophyceae.

1. Class-Chlorophyceae (Green Algae)
The members of Chlorophyceae are commonly called green algae. There are about 7000 species in this class.
The reserve food material is starch.
The characteristic features of Chlorophyceae are discussed below
(i) Habitat These are mostly marine forms, only some are freshwater. Chlorella can tolerate moderately warm waters. Snow dwelling forms are called cryophytes, e.g. Chlamydomonas nivalis, Scotiella, etc.

(ii) Cell Organisation Cell walls contain cellulose (inner layer) and pectose (outer layer) in most of the green algae. The chloroplasts may be discoid, plate-like, reticulate, cup-shaped, spiral or ribbon-shaped.
The chloroplasts contain photosynthetic pigments chlorophyll- a and b. Most of the members have one or more storage bodies called pyrenoids located in the chloroplasts. Pyrenoids contain protein besides starch.
Some algae may store food in the form of oil droplets also.

(iii) Thallus These are unicellular, colonial, coenocytic and multicellular forms. Unicellular green algae can be flagellate, (Chlamydomonas) or non-flagellate (Chlorella). Acetabularia (umbrella plant) has a single cell upto 10 cm long with distinction of nucleus containing rhizoid, elongated stalk and umbrella-like cap.
A colony for fixed number of individual cells (Volvox) is called coenobium. Coenocytic or siphonaceous thallus occurs in Caulerpa. Unbranched filamentous thallus in Ulothrix, Spirogyra heterotrichous in Stigeoclonium and parenchymatous in Ulva.

(iv) Reproduction The members of Chlorophyceae reproduce vegetatively, asexually and sexually by various methods. Vegetative reproduction occurs through cell division (unicellular forms), fragmentation, stolons, tubers, storage cells, etc. Asexual reproduction occurs by zoospores, aplanospores, hypnospores, akinetes and daughters colonies. Sexual reproduction may be isogamous, anisogamous or oogamous.

(v) Life Cycle It can be haplontic (e.g. Spirogyrai) diplontic (e.g. Cladophora) and haplodiplontic (e.g. Ulva)

2. Class-Phaeophyceae (Brown Algae):
The members of Phaeophyceae contain fucoxanthin pigment and include phycocolloid rich multicellular eukaryotic algae. Its common members are seaweeds called kelps. This class is comprised of about 2000 species.
(i) Habitat Brown algae are mostly marine. These are found mostly in colder seas or during cold seasons in tropical regions.

(ii) Size They range from simple branched, filamentous forms (Ectocarpus) to profusely branched forms as represented by kelps (Macrocystis).
These represent some of the largest algae, i.e. Macrocystis (40-100 m) and Nereocystis (20-30 m).

(iii) Cell Organisation All members are multicellular. Cell wall is composed of cellulose, pectose and phycocolloids. The cellulosic wall of vegetative cells is usually covered on the outside by a gelatinous coating of algin.

Brown algae (Phaeophyceae)

(iv) Thallus It is heterotrichous filament with both prostrate and upright branches (Ectocarpus). The parenchymatous structure is found in higher forms. The plant body of large forms often differentiated into holdfast (it usually attaches to the substratum) a stalk called the stipe and lamina (frond), which is photosynthetic. Conducting tubes or trumpet hyphae are present in larger brown algae or kelps. They help in conduction of food materials.

(v) Photosynthetic Pigments and Colour These include chlorophyll-a, c and carotenoids. They range in colour from olive green to various shades of brown depending upon the amount of the xanthophyll and fucoxanthin present in them.

(vi) Food Reserve It remains in the form of complex carbohydrates such as laminarin or mannitol.

(vii) Flagellation These contain heterokont flagellation with one smooth (whiplash) and other one tinsel flagella.

(viii) Reproduction Vegetative reproduction occurs through fragmentation (e.g. Sargassum), adventitious branches and stolons (e.g. Dictyotd).
Asexual reproduction by biflagellate zoospores, which are pear-shaped having two unequal laterally attached flagella.
Sexual reproduction occurs by isogamy, anisogamy and oogamy. Union of gametes may take place in water or within the oogonium (oogamous species). The gametes are pyriform (pear-shaped) and have two laterally attached flagella. ,

(ix) Life Cycle Isomorphic alternation of generations is found in some brown algae, e.g. Ectocarpus,
Dictyota. In many brown algae, the diploid , generation or phase is dominant. The haploid phase is either microscopic or represented by gametes only (e.g. Fucus).

Question 2.
Name plant group which bears archegonia and describe the characteristic features of first archegoniate land plant.
Answer:
Archegonia is found in bryophytes.
Bryophytes:
These include the various mosses and liverworts. These are non-vascular embryophytes, characterised by the presence of an independent gametophyte and parasitic sporophyte.
1. Habitat
Bryophytes commonly grow in moist, shaded areas in hills. These are also called amphibians of the plant kingdom because, these can live in soil, but are dependent on water for sexual reproduction.
Some bryophytes grow in diverse habitats, such as

• Aquatic, e.g. Riccia fluitans, Ricciocarpus, Riella
• Epiphyte, e.g. Radula, Dendroceros
• Saprophyte, e.g. Buxbaumia, Cryptothallus
• Dry habitats, e.g. Polytrichum
• Deserts, e.g. Tortula desertorum
• Dry rocks, e.g. Porella

2. Thallus Organisation
The plant body of bryophytes is more differentiated than that of algae. It is thallus-like, prostrate, erect and remain attached to the substratum by unicellular or multicellular rhizoids. Root, stem and leaves are not present on thallus.

3. Sex Organs
The main plant body is haploid that produces gametes, hence, it is called gametophyte. The sex organs in bryophytes are multicellular, the male sex organs in bryophytes is called antheridium (which produces biflagellate antherozoids) and the flask-shaped female sex organ is called archegonium (produces a single egg).

4. Reproduction
Sexual type of reproduction is common. The antherozoids are released into water where they come in contact with archegonium.

• Fertilisation It occurs inside the archegonium. The egg secretes a chemical which attracts spermatozoids. Sperms require a thin film of water for swimming and reaching the dehisced archegonium. One sperm fuses with an egg and produces a diploid zygote. Zygotes do not undergo reduction division immediately instead, they produce a multicellular body called sporophyte.
• Dependent Sporophyte The sporophyte is not free-living, it remains attached to the photosynthetic gametophyte for nourishment. Some cells of the sporophyte undergo reduction division (meiosis) to produce haploid spores. These spores germinate to produce gametophyte.
• Sporogonium The sporophyte of bryophytes is also called sporogonium because it is dependent on the gametophyte and is meant for producing spores.

5. Life Cycle
Bryophytes have heteromorphic alternation of generations. The gametophyte may be produced directly or through a first formed juvenile stage called protonema.

Antheridum, archegonium and lifecycle of Funaria (Moss) showing alternation of generations

Economic importance of Bryophytes:
Bryophytes in general are of little economic importance. But, several species have some uses.

1. Some mosses provide food for herbaceous mammals, birds and other animals.
2. Species of Sphagnum (a moss), provides peat that have long been used as fuel. It has the capacity to hold water as packing material for transshipment of living materials.
3. Mosses along with lichens are the first organisms to colonise rocks. Hence, these help in biological succession. They decompose rocks making the substrate suitable for the growth of higher plants.
4. Mosses form dense mats on the soil. They reduce the impact of falling raindrops and thus, prevent soil erosion.
5. Marchantia has medicinal properties to cure lungs and liver infections. It also has anti-tumour properties.

Question 3.
If both gymnosperms and angiosperms bear seeds, then why they are classified separately?
Answer:
Gymnosperms and angiosperms are classified separately although they both bear seeds because of following reason
(i) Ovules in gymnosperms are naked. In angiosperms, they are enclosed inside the ovary.
(ii) Wood is non-porous is gymnosperm, i.e. the vessels are absent.

Gymnosperms	Angiosperms
Megasporophylls are woody and there is no rolling of megasporophylls.	Magasporophylls are softer and rolled into ovary, style and stigma.
Ovules are exposed.	Ovules are enclosed in ovary.
Archegonia is present.	Archegonia is absent.
Pollen enters micropyle directly.	Pollen germinates on stigma, pollen tube passes through style to enter ovary.
Single fertilisation.	Double fertilisation
Endosperm is haploid and formed before fertilisation.	Endosperm is triploid and formed after fertilisation.
Seeds are exposed because there in no ovary, so no fruit formation.	Seeds are enclosed in a fruit which are formed after fertilisation.

Question 4.
What are gymnosperms? Describe their economic importance.
Answer:
The gymnosperms (Gymnos – naked; sperma – seeds) are plants in which the ovules are not enclosed by any ovary wall and remain exposed, both before and after fertilisation. These are small groups of seed plants which are represented by only 900 living species. Unlike bryophytes and pteridophytes, in gymnosperms, the male and the female gametophytes do not have an independent free-living existence. They remain within the sporangia retained on the sporophytes.

Economic Importance of Gymnosperms:

1. Seeds of Pinus gerardiana (chilgoza) are used as food after roasting. Some other edible gymnosperm plant parts are endosperm of Ginkgo, seed kernel of some Cycas and Gnetum, sago grains from stems of Cycas, etc.
2. Gymnosperms provide softwood for construction, plywood and paper industry.
3. Branches of gymnosperm trees are used as fuel.
4. Saw dust of conifers is used in making plastics and linoleum.
5. Resin is a semifluid secreted by special tubes of a number of conifers. It helps in sealing female cones after pollination, scale leaves around leaf bases and apical buds. Resin is distilled to obtain turpentine and resin. Turpentine is used for thinning paints, varnishes, etc., and resin is used for sealing joints of wheel, preparation of writing paper, oil, clothes, etc.
6. Ephedrine an antibiotic is obtained from Ephedra. It is used for curing respiratory problems and asthma.
7. Taxol is an anticancer drug obtained from Taxus.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 2 Classification of Living World Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 2 Question Answer Classification of Living World

Classification of Living World Class 11 Questions and Answers CHSE Odisha

A. Very Short Answer Type Questions

Fill in the blanks choosing appropriate answers given in the brackets.

Question 1.
In two kingdom system of classification _______ were ignored. (eukaryotes, plants, prokaryotes, animals)
Answer:
Prokaryotes

Question 2.
The major component of the cell wall of bacteria is _______. (peptidoglycan, cellulose, chitin, lipoprotein)
Answer:
Peptidoglycan

Question 3.
The core of the viruses are composed of _______ .(protein, carbohydrate, vitamins, nucleic acid)
Answer:
Nucleic acid

Question 4.
Fungi have _______ mode of nutrition. (absorptive, ingestive, autotrophic, epiphytic)
Answer:
Absorptive

Question 5.
Viruses are living because they grow and _______(respire, reproduce, recognise hosts, transmissible)
Answer:
Reproduce

Choose the correct answer from the words given in the brackets.

Question 6.
In two kingdom system, the status of one of the following type of organisms was ignored.
(Fungi, Bacteria, Bryophytes, Pteridophytes)
Answer:
Bacteria

Question 7.
Three-kingdom system of classification was proposed by
(Haeckel, Linnaeus, Whittaker, Copeland).
Answer:
Haeckel

Question 8.
One of the following components of viruses penetrate into the host cell
(protein, capsid, nucleic acid, carbohydrates)
Answer:
Nucleic acid

Question 9.
The character which separates plants from animals is the occurrence of (ribosome, nucleus, mitochondria, cell wall)
Answer:
Cell wall

Question 10.
Fungi show one of the following types of nutrition.
(Autotrophic, absorptive, ingestive, swallowing)
Answer:
Absorptive

B. Short Answer Type Questions

Write notes in 2 to 3 relevant and meaningful points.

Question 1.
Two kingdom system of classification
Answer:
Two Kingdom Classification System
Linnaeus (the father of taxonomy) divided all the living organisms into two kingdoms in 1758. These are Plantae and Animalia.

Question 2.
Three kingdom system of classification
Answer:
Three Kingdom Classification System
Ernst Haeckel in 1866, classified living organisms into three kingdoms – Plantae, Protista and Animalia. The new kingdom – Protista included all those organisms which lack the capability of tissue differentiation. These are algae, fungi, protozoans, bacteria and slime moulds. Later, kingdom – Protista was reserved only for unicellular organisms.
An outline of three kingdom system of classification is given below

Question 3.
Characteristic features of algae.
Answer:
Characteristic Features of Algae

• Algae are simple , thalloid, chlorophyll bearing (green), autotrophic and largely aquatic (both freshwater and marine) plant.
• Algae reproduce by vegetative, asexual and sexual methods.
• Their size ranges from unicellular microscopic forms like Chlamydomonas to colony forming forms Volvox and to filamentous forms like Ulothrix and Spirogyra.

Question 4.
Characteristic features of fungi.
Answer:
Characteristic Features of Fungi

• Fungi are uni or multicellular-achlorophyllous, spore bearing thallophytes.
• Their cell wall is made up of chitin.
• These are heterotrophic, may be saprophytic or parasitic.
• Fungi are generally multicellular, thread-like structures, branched in various patterns called mycelia. These constitute the thallus. Its individual branches are called hypha.

Question 5.
Viruses, as living beings
Answer:
Viruses are intermediate between living and non-living objects.
They resemble non-living objects in

• Lacking protoplast.
• Ability to get crystallised.
• High specific gravity which is found only in non-living objects.
• Absence of respiration and energy storing system.
• Absence of growth and division.
• Cannot live independent of a living cell.

They resemble living objects in

• Presence of genetic material (DNA or RNA).
• Capable of mutation.
• Irritability.
• Can grow and multiply inside the host cell.

Question 6.
Mycoplasma
Answer:
Mycoplasma are organisms that completely lack a cell wall. They were discovered by Roux (1898) in pleural fluid of cattle suffering from pleuropneumonia. The organisms are often called PPLOs (Pleuropneumonia Like Organisms).
The characteristic features of mycoplasma are given below

1. Mycoplasmas are the smallest (0.1-0.5 μm) free-living microorganisms that are so small that they can easily pass through bacteria-proof filters. These occur saprotrophically in soil, sewage water and in dead and decaying organic matter. Some of them also parasitise plants, animals and human beings. Pathogenic mycoplasmas cause diseases in their hosts.
2. They are unicellular with plasma membrane as the outermost boundary. The cell membrane is made up of protein, lipids and cholesterol.
   
   Structure of Mycoplasma
3. DNA is naked (because of the absence of histones) and ribosomes of 70S type are present.
4. Mycoplasmas possess heterotrophic nutrition. Examples are Mycoplasma gallisepticum, M. laidlawii. They cause pleuropneumonia in domestic animals, mycoplasmal urethritis in humans.
5. These can survive without oxygen.

Question 7.
Phycomycetes
Answer:
The members of Phycomycetes are found in aquatic habitats and on decaying wood in moist and damp places or as obligate parasites on plants. Phycomycetes can be distinguished into two sub-classes, i.e. Zygomycetes (saprophytic) and oomycetes (plant parasites).
General characteristics of phycomycetes are as follows

1. Mycelium is aseptate and coenocytic.
2. Hyphal wall contains microfibrils of cellulose, chitin or both.
3. Asexual reproduction involves the endogenous formation of sporangia. The sporangia function as conidia in dry habitats and as zoosporangia under wet conditions.
4. Zoospores may be uniflagellate or biflagellate with flagella being anterior, lateral or posterior. A zoospore is formed by the fusion of two gametes.
5. The gametes can be similar in morphology (isogamous) or dissimilar (anisogamous or oogamous).
6. Disease caused by the members of Phycomycetes are white rust (Albugo), late blight of potato (Phytophthora infestans), downy mildew (Peronospora parasitica), etc.
   Examples include oomycetes Albugo (parasitic fungi on mustard), Pythium, Plasmospara, Phytophthora. Zygomycetes Rhizopus (the bread mould), Mucor (pin mould), etc.
   

Differentiate in 2 to 3 relevant meaningful points.

Question 1.
Prokaryotes and Eukaryotes
Answer:
Differences between prokaryotes and eukaryotes are

Prokaryotes	Eukaryotes
No membrane bound nucleus.	Have nucleus with nuclear membrane, chromatin, nucleoplasm, nuclear matrix and nucleoli.
Cell walls made up of peptidoglycan.	Cell walls, if present, made up of cellulose (as in fungi).
No membrane bound organelles.	Membrane bound organelles present.
Have pilli and fimbriae (for adhesion) and flagella (for propulsion).	Have cilia or flagella (for movement).
Cell size ranges from 0.5μ.m – 100μm	Cell size ranges from 10μ.m – 150μm

Question 2.
Protista and Monera
Answer:
Differences between Protista and Monera are

Monera	Protista
Cell wall is made up of peptidoglycan.	It is made up of cellulose.
Respiratory apparatus is present in respiratory membrane.	It is present in mitochondria.
Ribosomes are 70S type.	Ribosomes are 80S type.
These are prokaryotic and have naked circular DNA.	Eukaryotic, linear DNA is present in nucleus.
Extrachromosomal DNA is present in the form of plasmids.	Extrachromosomal DNA is present in organelles like mitochondria and chloroplast.

Question 3.
Mycota and Planate
Answer:
Differences between Mycota and Planate are

Mycota (Fungi)	Plantae
They are eukaryotic, unicellular or multicellular organisms with chitinous cell wall.	They are eukaryotic, multicellular organisms with cellulosic cell wall.
The members of this kingdom do not possess photosynthetic pigments and are therefore heterotrophic.	The members of the Plantae group contain photosynthetic pigment ’ and gain their energy through it and are therefore autotrophic.
They have few or no storage molecules.	Starch is their main storage molecule.

Question 4.
Amoeboid protozoans and ciliated protozoans
Answer:
Differences between amoeboid protozoans and ciliated protozoans are

Amoeboid protozoans	Ciliated protozoans
Protozoans with false feet or pseudopodia which moves by amoeboid movement, accomplished by cytoplasmic streaming.	Protozoans that move using cilia by ciliary movement. (like Paramecium)
Ingest food by phagtocytosis.	Ingest food through oral groove covered by cilia.
Reproduction by binary fission.	Reproduction by binary fission or conjugation.

Question 5.
Archaebacteria and Eubacteria
Answer:
Differences between Archaebacteria and Eubacteria are

Archaebacteria	Eubacteria
Peptidoglycan is absent in cell wall. It is made up of cellulosic carbohydrate.	Ceil wall is made up of peptidoglycans.
It is a single layer of branched chain lipids.	Plasma membrane consists of phospholipids.
Genes are interrupted by introns like eukaryotes.	Genes are not interrupted by non-coding zones or introns.

C. Long Answer Type Questions

Question 6.
Give an account of five-kingdom system of classification. Add a note on its merits and demerits.
Answer:
Five Kingdom Classification System:
This classification system was proposed by RH Whittaker in 1969. Before 1969, the classification systems for the living organisms had undergone several changes over time.
In this classification Whittaker introduced Fungi, as a separate kingdom along with Monera, Protista, Plantae and animals.
The main criteria for classification used by Whittaker is
(i) Cell structure
(ii) Mode of nutrition
(iii) Thallus organisation
(iv) Reproduction
(v) Phylogenetic relationships

Merits of Five Kingdom Classification System:
Merits of five kingdom classification system are
(i) Euglena and other transition types which had been included both amongst plants and animals are given proper place under kingdom-Protista.
(ii) Fungi have their own biochemical, physiological and structural organisation. They have never been related to plants. In this system of classification, fungi are separately placed.
(iii) A separate kingdom-Monera including prokaryotes has been created. Monerans differ from all other organisms in their cellular, reproductive and physiological organisations.
(iv) The five kingdom classification system is based on cellular organisation, the mode of nutrition and complexity of structure. These were the basic factors used in earliest two kingdom system of classification.
(v) This system of classification was also based on origin and evolution of the organisms hence, phylogenetic one.
(vi) The plant and animal kingdoms are more homogenous than they were in the two kingdom system of classification.

Demerits of Five Kingdom Classification System:
Demerits of five kingdom classification system are
(i) Animal protozoans have been included in kingdom-Protista, which also includes unicellular plants. They show different modes of nutrition.
(ii) Chlorella and Chlamydomonas, though unicellular are included under the kingdom-Plantae. They should be kept in Protista.
(iii) Euglena like organisms and slime moulds with flexible life style may need the creation of an intermediate kingdom other than Protista.
(iv) Viruses and viroids are not kept in proper place in this system.
(v) Lichens have also not been placed in this system.
(vi) All groups are polyphyletic and not monophyletic in origin as underlined by this classification.

Question 7.
Give characteristic features of members of five kingdoms that were proposed by RH Whittaker.
Answer:
The five kingdom classification system classify all the living organisms into five kingdoms named Monera, Protista, Fungi, Plantae and Animalia.

The important characteristics of each kingdom are as follows

Kingdom-Monera:
The kingdom-Monera includes all prokaryotes such as bacteria, mycoplasmas, Actinomycetes and cyanobacteria (blue-green algae).
The characteristic features of kingdom-Monera are given below
(i) They are simplest and most primitive, unicellular prokaryotes.
(ii) The cell wall contains peptidoglycan or murein (no cellulose), but the membrane bound cell organelles are not present.
(iii) They have various types of modes of nutrition like saprophytic, parasitic, chemoautotrophic, photoautotrophic and symbiotic.
(iv) DNA is naked and it lies inside the cytoplasm in coiled form. This is called nucleoid or false nucleus.
(v) Reproduction is by asexual methods. Gametes are not present.
(vi) Mitotic spindle is absent.
(vii) The flagella, if present, are single-stranded instead of being several stranded as in eukaryotes. These contain a protein called flagellin.
(viii) Some of the monerans have the ability to fix nitrogen into useful nitrates.

Kingdom-Protista:
Kingdom-Protista includes all single-celled eukaryotes, but the boundries of this kingdom are not well-defined. This kingdom was first proposed by Ernst Haeckel (1866).
Physiologically, kingdom-Protista acts as a connecting link between the kingdom-Monera and the complex multicellular kingdoms-Fungi, Plantae and Animalia. Kingdom-Protista includes the following categories such as dinoflagellates, chrysophytes, euglenoids, slime moulds and protozoans. The general characteristic features of kingdom-Protista are given below

1. These are mostly aquatic organisms. Some protists also live in the bodies of animals as parasites.

2. The cells are eukaryotic. These contain all membrane bound cell organelles like mitochondria, Golgi complex, endoplasmic reticulum, 80 S ribosomes, etc. Cell wall when present is constituted by cellulose.

3. Locomotion may either occur by pseudopodia (Amoeba, Euglypha), cilia (Paramecium), wriggling (sporozoans, non-flagellates) and mucilage propulsion (some protists like diatoms). Diatoms do not have any organelle for locomotion.

4. Protists show various modes of nutrition such as
• Photosynthetic (Holophytic) Dinoflagellates, diatoms and euglenoids.
• Holozoic (Zootrophic) Protozoans like Amoeba and Paramecium.
• Saprobic (Saprotrophic) In slime moulds.
• Parasitic Trypanosoma, Giardia, Plasmodium, Entamoeba.
• Mixotrophic In Euglena.
• Symbiotic In zooflagellates like
Trichonympha and Lophomonas.
• Pinocytosis In Amoeba to absorb soluble organic substances.

5. Most of the protists are aerobic. However, some protists that live at the bottom of aquatic habitats can respire anaerobically.

6. Protists reproduce asexually and sexually by a process involving cell fusion and zygote formation.
The major groups of Protista are
(a) Protistan algae (photosynthetic protists).
(b) Slime moulds (consumer-decomposer protists).
(c) Protozoan protists.

Kingdom-Fungi or Mycota:
(i) These are uni or multicellular, achlorophyllous, spore bearing thallophytes.
(ii) Cell wall consists of cellulose or chitin or both.
(iii) In most cases, multicellular, thread-like structures, branched in various patterns are called mycelia. These constitute the thallus. Individual branches of it are called hypha.
(iv) These are heterotrophic, may be saprophytic or parasitic.
(v) Mode of nutrition is absorptive which means the enzymes secreted by the hyphae digest complex nutrients of the host. The simplified nutrients are then absorbed by the organisms.
(vi) The reproduction may be vegetative, asexual and sexual. Asexual reproduction takes place under favourable conditions.
(vii) The reserve food materials are glycogen, e.g. Aspergillus, Penicillium, Saccharomyces (yeast).

Kindom-Plantae:
(i) It includes mainly multicellular, eukaryotic and autotrophic organisms.
(ii) The major component of the cell wall is cellulose.
(iii) The cells contain few large vacuoles and no structure like centrosome.
(iv) These organisms are also called producers.
(v) The reserve food material is generally starch.
(vi) Growth in higher plants is always terminal.
(vii) The trees generally grow being fixed to the soif
(viii) Reproduction may be vegetative, asexual or sexual,
e.g. multicellular algae, bryophytes, pteridophytes, phanerogams.

Kingdom-Animalia:
Animal kingdom contains heterotrophic, eukaryotic organisms that are multicellular and their cells lack cell walls. The main source of food for animal kingdom are plants directly or indirectly.

The food is digested in alimentary canal and is reserved as glycogen or fat. The mode of nutrition is holozoic, i.e. by ingestion of food.
A definite growth pattern is present. Adults have definite shape and size. The higher forms have well-developed sensory and neuromuscular mechanism. Locomotion is present.
Sexual reproduction occurs by copulation followed by fertilisation of gametes and embryonic development.

Odisha State Board CHSE Odisha Class 11 Biology Solutions Chapter 1 Biodiversity Textbook Questions and Answers.

CHSE Odisha 11th Class Biology Chapter 1 Question Answer Biodiversity

Biodiversity Class 11 Questions and Answers CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
How many years ago did life originate on Earth?
(a) 3 billion
(b) 3.5 billion
(c) 4 billion
(d) 4.5 billion
Answer:
(b) 3.5 billion

Question 2.
Which one of the following is a characteristic feature of living?
(a) Reproduction
(b) Response to stimuli
(c) Metabolism
(d) All of these
Answer:
(d) All of these

Question 3.
Which of these statements is wrong?
(a) Breakdown of glucose molecules in respiration is catabolism
(b) Many metabolic processes are similar in microbes, plants and animals
(c) In some non-living objects metabolic processes also occur
(d) Immune system is a characteristic of living beings
Answer:
(c) In some non-living objects metabolic processes also occur

Question 4.
Find out the wrong one.
(a) A single-celled organism grows only in mass
(b) A multicellular organism grows not only in mass, but also in number of cells
(c) Fungi produce large number of spores during reproduction
(d) Gametes fuse to produce offsprings in asexual reproduction
Answer:
(d) Gametes fuse to produce offsprings in asexual reproduction

Question 5.
Identify the incorrect statements.
(a) Plants are influenced by external stimuli such as light, temperature and water
(b) All organisms do not possess consciousness
(c) Combined interactions of molecules make life to continue
(d) Organisms have the ability to regulate the chemical substances entering into their bodies
Answer:
(b) All organisms do not possess consciousness

Question 6.
Richness of the living species on earth is termed as
(a) ecosystem
(b) community
(c) biodiversity
(d) population
Answer:
(c) biodiversity

Question 7.
Who is referred to as the Father of Taxonomy?
(a) WG Rosen
(b) EO Wilson
(c) John Ray
(d) Carolus Linnaeous
Answer:
(d) Carolus Linnaeous

Question 8.
Full form of ICBN
(a) International Code for Botanical Nomenclature
(b) International Code for Biological Nomenclature
(c) International Code for Bacterial Nomenclature
(d) International Code for Bryophyte Nomenclature
Answer:
(a) International Code for Botanical Nomenclature

Question 9.
Who proposed the three domain system of biological classification?
(a) Carl Woese
(b) RH Whittaker
(c) Charles Darwin
(d) Robert Hooke
Answer:
(a) Carl Woese

Question 10.
In the scientific name of man, sapiens represents name of the
(a) genus
(b) species
(c) scientist
(d) place
Answer:
(b) species

Question 11.
The scientific names are derived from which language?
(a) English
(b) French
(c) Latin
(d) Greek
Answer:
(c) Latin

Question 12.
Under which domain does the kingdom-protista come?
(a) Archaea
(b) Bacteria
(c) Eukarya
(d) Plantae
Answer:
(c) Eukarya

Question 13.
Which is not true about the organisms of the domain Bacteria?
(a) Have diacyl glycerol diester lipids in their cell membranes
(b) Have no nuclear membrane
(c) Contain a genome composed of bacterial rRNA
(d) Thermophiles and halophiles come under the domain
Answer:
(d) Thermophiles and halophiles come under the domain

Question 14.
Which of the following about organisms is not dealt by Taxonomy?
(a) Nomenclature
(b) Identification
(c) Classification
(d) Evolutionary history
Answer:
(d) Evolutionary history

Question 15.
Which chemical solution is used for the preservation of organisms?
(a) Nitric acid
(b) Formalin
(c) Chloroform
(d) Sodium hydroxide
Answer:
(b) Formalin

Question 16.
Name the botanical garden present in Bengaluru.
(a) Lai Bagh
(b) Empress Garden
(c) Indian Botanic Garden
(d) Malampuzha Garden
Answer:
(a) Lai Bagh

Question 17.
Binomial System of Nomenclature was proposed by
(a) Carolus Linnaeus
(b) RH Whittaker
(c) Carl Woese
(d) JB Lamarck
Answer:
(a) Carolus Linnaeus

Very Short Answer Type Questions

Question 1.
Name the author of the book ‘Systerna Naturae’.
Answer:
Carolus Linnaeus

Question 2.
Under which domain comes the kingdom- Animalia?
Answer:
Domain Eukarya

Question 3.
Arrange the following taxa from highest to lowest : Genus, Class, Phylum, Order.
Answer:
Phylum → Class → Order → Genus

Question 4.
Which botanical garden is named after Sir Jagdish Chandra Bose?
Answer:
Acharya Jagadish Chandra Bose Indian Botanical Garden, Kolkata

Question 5.
Which district Nanadankanan Biological Park is situated?
Answer:
Bhubaneswar

Short Answer Type Questions

Answer the following in three sentences each

Question 1.
What is taxonomical hierarchy?
Answer:
Taxonomic Hierarchy
The taxonomic hierarchy is the system of arranging taxonomic categories in a descending order. It was first introduced by Linnaeus (1751) and hence, it is also known as Linnaean hierarchy.
Groups represent category and category further denotes rank. Each rank or taxon represents a unit of classification. These taxonomic groups/categories are distinct biological entities and not merely morphological aggregates.

Taxonomic categories showing hierarchical arrangement in ascending order

Question 2.
Explain the concept of species.
Answer:
Taxonomic studies consider a group of individual organisms with fundamental similarities as a species. Species is considered as the lowest or basic taxonomic category, which consists of one or more individuals of a population that resemble one another more closely than individuals of other species.

The members of species interbreed freely and are reproductively isolated from other species, e.g. Mangifera indica (mango), Solarium tuberosum (potato) and Panthera leo (lion). All the three names indica, tuberosum and leo represent the specific epithets while, the first words Mangifera, Solanum and Panthera are genera and represent another higher level of taxon or category.

Each genus may have one or more than one specific epithets representing different organisms, but having morphological similarities, e.g. Panthera has another specific epithet called tigris and Solanum includes species like nigrum and melongena.

Question 3.
State the usefulness of taxonomic tools.
Answer:
Taxonomic tools include museums, zoos, herbaria, botanical gardens, etc. They are required because taxonomic study of plants, animals and other organisms is very much essential. The biologists need the help of some taxonomical tools to gather knowledge on various bioresources, their diversity and measures required for their conservation.

Question 4.
Write down the names of the phylum, class order and family and the scientific name in respect of man, housefly, mango and wheat.
Answer:
(some organisms with their taxonomic categories)

Question 5.
What are the objectives of zoological parks?
Answer:
These are the places where wild animals are kept in protected environments under human care and which enable us to learn about their food habits and behaviour. Zoological parks provide natural habitat to the animals.
In India there are about 200 zoological parks. These zoos are managed by the Central Zoo Authority of India. The World Zoo Conservation Strategy (WZCS) refers to all these zoological institutions as zoos.

Role of Zoological Parks

1. Zoos are the centres for conservation of threatened and rare animal species.
2. These provide sites for ex situ conservation through captive breeding of endangered animals.
3. The zoological parks increase the public interest in an understanding of wildlife.
4. These are the centres for recreation and education.

Some famous zoos of India

Zoos	Place
National Zoological Park	Delhi
Nandankanan Zoo	Odisha (Bhubaneshwar)
Nehru Zoological Park	Hyderabad
Sanjay Gandhi Jaivik Udyan	Bihar (Patna)
Rajiv Gandhi Zoological Park	Maharashtra (Pune)
Alipore Zoological Garden	Kolkata
Guwahati Zoo	Assam
Madras Crocodile Bank Trust	Tamil Nadu (Chennai)
Mysore Zoo	Karnataka
Allen Forest Zoo	Uttar Pradesh (Kanpur)

Differentiate between following (For Complete Chapter)

Question 1.
Anabolism and Catabolism
Answer:
The important differences between anabolism and catabolism are

Anabolism	Catabolism
It is the sum total of constructive processes.	It is the sum total of destructive processes.
Complex substances are formed from simpler ones.	Simpler substances are formed from complex ones.
Energy is stored.	Energy is released.
Anabolism is required for growth and maintenance.	Catabolism is required for performance of activities.

Question 2.
Archaea and Bacteria
Answer:
The differences between archaea and bacteria are

Archaea	Bacteria
Their ceil wall lacks peptidoglycan.	Their cell wall is made up of peptidoglycan.
Have several kind of RNA polymerase.	Have one kind of RNA polymerase.
The archae constitute a domain or kingdom of single-celled microorganisms. These microbes are prokaryotes, meaning that they have no cell nucleus or any other membrane bound organelles in their cells.	Bacteria constitute large domain of prokaryotic microorganisms. Typically a few micrometers in length, bacteria have a number of shapes, ranging from spheres to rods and spirals.

Question 3.
Taxonomy and Systematics
Answer:
The differences between taxonomy and systematics are

Taxonomy	Systematics
It is related to identification, nomenclature and classification.	It is the science of identification nomenclature, description and classification.
Taxonomic studies are based on rules and principles of classification.	Systematics is related to unique properties at every level of classification.

Question 4.
Genus and Species
Answer:
The differences between genus and species are

Genus	Species
Genus rank higher than the species in the taxonomic hierarchy.	Species is the most specific and comes at the lowest in taxonomic hierarchy.
Two fertile animals from one genus may or may not produce a fertile progeny.	Two fertile animals from one species can produce a fertile progeny.
Genus is the first name in binomial nomenclature.	Species is the second name in binomial nomenclature.

Question 5.
Museum and Herbarium
Answer:
The differences between museum and herbarium are

Museum	Herbarium
Museum contains many preserved specimens of animals and plants.	Herbarium is a collection of plant specimens only and data relating to them for future taxonomic studies and research.
Preservation in museum is done in jars, containers, stuffed specimens, etc.	The specimens preserved may be whole plants or plant parts that are dried, pressed and mounted on sheets of paper.

Question 6.
Botanical Gardens and Herbarium
Answer:
The differences between botanical gardens and herbarium are

Botanical Gardens	Herbarium
Places where living plant collections of different varities are maintained.	Places where a collection of dried, presed and well preserved plants species are kept.
These include medicinal, economic important, industrial, cultivated ornamental, etc., plants.	Here plant materials are arranged according to a system of classification.
Here the living plants are only grown.	It also possesses wood materials, microslides, photographs, drawings, etc.
Modem botanical gardens are quite big and possess greenhouses, a herbarium, a library and research laboratories.	Herbarium is comparatively a small institution present inside a botanical garden or in an university.

Question 7.
Taxon and Species
Answer:
The difference between taxon and species are

Taxon	Species
Taxon is the representation of any level of taxonomic category.	Species includes all the . organisms that are similar to breed and produce fertile offspring.
It is constructed by individual biological objects.	Species is one taxonomic category and is an abstract term.
Taxon can be of monophyletic or polyphyletic generation.	Species is always

Question 8.
Classification and Taxonomy
Answer:
The differences between classification and taxonomy

Classification	Taxonomy
It is systematic arrangement In groups or categories according to established criteria.	It is orderly classification of plants and animals according to their presumed natural relationship.
The term is broad one that encompasses any type of grouping according to criteria.	It is the process of giving names to things or groups of things according to their positions in a hierarchy.

 

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 17 Environmental Issues Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 17 Environmental Issues

Environmental Issues Class 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
The major pollutant from automobile exhaust is known as
(a) NO
(b) CO
(c) SO₂
(d) Soot
Answer:
(b) CO

Question 2.
Which air pollutant could cause rains to be acidic?
(a) Dust particles from cement factories
(b) Insecticides from crop sprays
(c) Smoke from wood fires
(d) Sulphur dioxide from coat-fired power stations
Answer:
(d) Sulphur dioxide from coat-fired power stations

Question 3.
Which process does not result in the return of carbon dioxide to the atmosphere?
(a) Combustion of fossil fuels
(b) Decomposition of humus
(c) Respiration by bacteria
(d) Photosynthesis by green plants
Answer:
(d) Photosynthesis by green plants

Question 4.
Which kind of power station produces sulphur dioxide causing air pollution and acid rain?
(a) Loal-fired
(b) Nuclear
(c) Hydroelectric
(d) Wind-powered
Answer:
(a) Loal-fired

Question 5.
Eutrophication in lakes is the direct result of
(a) a diminished supply of nitrates and phosphates
(b) industrial poisons
(c) nutrient enrichment such as nitrate and phosphate runoffs from the land
(d) an increase in predators
Answer:
(c) nutrient enrichment such as nitrate and phosphate runoffs from the land

Question 6.
Why does the oxygen concentration in the water decrease when sewage is discharged into a river?
(a) Decrease in the number of plants
(b) Increase in the number of fish
(c) Less oxygen absorbed from the air
(d) Rapid growth of bacteria
Answer:
(d) Rapid growth of bacteria

Question 7.
Minamata disease is due to pollution of water by
(a) mercury
(b) lead
(c) tin
(d) methylisocyanate
Answer:
(a) mercury

Question 8.
The effects of radioactive pollutants depend upon
(a) the rate of diffusion
(b) energy releasing capacity
(c) rate of deposition of contaminant
(d) All of the above
Answer:
(d) All of the above

Question 9.
The most harmful types of environment pollutants are
(a) human organic wastes
(b) wastes from faecal
(c) non-biodegradable chemicals
(d) natural nutrients present in excess
Answer:
(c) non-biodegradable chemicals

Question 10.
Taj Mahal is threatened to ……….. the effect of
(a) chlorine
(b) SO₂
(c) oxygen
(d) hydrogen
Answer:
(b) SO₂

Question 11.
CO is a pollutant because it
(a) inactivates nerves
(b) combines with oxygen
(c) combines with Hb
(d) inhibits growth
Answer:
(c) combines with Hb

Question 12.
Flyash is an environmental pollutant produced by
(a) thermal power plant
(b) oil refinery
(c) fertilisation plant
(d) strip mining
Answer:
(d) strip mining

Question 13.
Which type of pollution is caused by scooters?
(a) Air pollution
(b) Soil pollution
(c) Both (a) and (b)
(d) Water pollution
Answer:
(a) Air pollution

Question 14.
Acid rain occurs in areas where
(a) large plantation occurs
(b) small plantation occurs
(c) there are big industries and the atmosphere is polluted with SO₂
(d) there are no industries
Answer:
(c) there are big industries and the atmosphere is polluted with SO₂

Question 15.
Air pollution effects are usually found on the
(a) leaves
(b) flowers
(c) stems
(d) roots
Answer:
(a) leaves

Question 16.
Eutrophic lakes are highly
(a) productive
(b) enriched with phosphates
(c) heavy metal
(d) None of the above
Answer:
(b) enriched with phosphates

Question 17.
Global warming can be controlled by
(a) reducing reforestation, increasing the use of fossil fuel
(b) increasing deforestation, slowing down the growth of human population
(c) increasing deforestation, reducing efficiency of energy usage
(d) reducing deforestation, cutting down use of fossil fuel
Answer:
(d) reducing deforestation, cutting down use of fossil fuel

Question 18.
The common refrigerant that is responsible for the depletion of stratospheric ozone is
(a) CFC
(b) NO
(c) SO₂
(d) Ozone
Answer:
(a) CFC

Question 19.
Slash and burn agriculture is known as
(a) striping farming
(b) intercrop farming
(c) jhum cultivation
(d) intensive farming
Answer:
(c) jhum cultivation

Question 20.
Ozone hole is the
(a) absence of O₃ in stratosphere
(b) presence of O₃ in stratosphere
(c) deficiency of O₃ in stratosphere
(d) deficiency of O₃ in stratosphere
Answer:
(c) deficiency of O₃ in stratosphere

Question 21.
Ozone depletion is occurring due to
(a) PCB
(b) CO
(c) PAN
(d) None of these
Answer:
(d) None of these

Question 22.
The most common and abundant greenhouse gas is
(a) methane
(b) CFC
(c) carbon dioxide
(d) nitrous oxide
Answer:
(c) Carbon dioxide

Question 23.
Women empowerment in Tehri-Garhwal by Sundarlal Bahuguna for the conservation of forests is popularly known as
(a) agro forestry
(b) shifting cultivation
(c) Chipko movement
(d) None of these
Answer:
(c) Chipko movement

Correct the following sentences, if required, by changing the underlined word (s)

Question 1.
Acid rain, a secondary effect of sound pollution.
Answer:
air pollution

Question 2.
The excessive growth of plants in water bodies due to enrichment of nutrients is called bioremediation.
Answer:
Eutrophication

Question 3.
Excessive nourishment that causes algal bloom is known as biomagnification.
Answer:
eutrophication

Question 4.
Photochemical smog consists of O₂ PAN and NO_x.
Answer:
It is Correct

Question 5.
Radioactive pollution is caused by α, ß, γ particles.
Answer:
It is Correct

Question 6.
Ozone hole is present above Antarctica.
Answer:
It is correct.

Question 7.
Greenhouse effect refers to cooling of earth.
Answer:
warming

Question 8.
Nitrogen is a greenhouse gas.
Answer:
Carbon dioxide

Fill in the blanks

Question 1.
Bhopal gas tragedy was due to the release of ……….. gas from Union Carbide’s pesticide plant.
Answer:
methyl isocyanate

Question 2.
The toxic metal that is used as an antiknocking agent in petrol engines of automobiles is ………… .
Answer:
lead (Pb)

Question 3.
The Bharat Emission Norm came into force from ……….. .
Answer:
2000

Question 4.
In a scrubber, the effluent containing sulphur dioxide is passed through spray of ………….. .
Answer:
lime or Water

Question 5.
Most hazardous metal pollutant of automobile exhaust is ……….. .
Answer:
CO

Question 6.
Melting of glaciers is an effect of ………… .
Answer:
global warming

Question 7.
Two greenhouse gases produced by anaerobes are ……….. and ………… .
Answer:
methane, carbon dioxide

Question 8.
In 1980s, the government of India introduced a concept known as ………… .
Answer:
Joint Forest Management

Express in one or two word(s)

Question 1.
The expression that reflects the depleted oxygen content in the extremely polluted water.
Answer:
Biochemical Oxygen Demand (BOD).

Question 2.
Expand DDT.
Answer:
Dichloro Diphenyl Trichloroethane.

Question 3.
Name the gas which was released during Bhopal gas tragedy.
Answer:
Methyl isocyanate

Question 4.
Which metal causes gangrenes?
Answer:
Arsenic

Question 5.
In which year Copenhagen conference was held?
Answer:
2009

Question 6.
In which year was Montreal Protocol signed?
Answer:
1987

Question 7.
Above which region of earth is ozone hole located?
Answer:
Antarctic region

Short Answer Type Questions

Question 1.
State the function of catalytic converter in automobile. Name any two metals used in these converters.
Answer:
Catalytic converters are used in automobiles to reduce the emission of poisonous gases. They convert unburnt hydrocarbons to carbon dioxide and water, carbon monoxide and nitrogen dioxide are converted to carbon dioxide and nitrogen gas respectively.

Question 2.
What are causes of air pollution?
Answer:
The various causes of air pollution are

• Smoke stacks of thermal power plants, forest fires, volcanic eruptions, etc.
• Garbage decomposition releases unwanted gases in the air.
• Excessive use of fossil fuels by automobiles and particulate air pollutants released by industries.

Question 3.
Write a short note on water pollution.
Answer:
Water pollution is any undesirable change in the physical, chemical or biological properties of water that may affect the human beings and aquatic species.
There are various types of water pollutants such as

• Domestic sewage
• Industrial waste
• Agricultural waste

The various effects of water pollution are

• Biomagnification
• Eutrophication
• Increase in Biochemical Oxygen Demand (BOD).

Question 4.
Write short note on algal bloom.
Answer:
Algal bloom is excessive growth of planktonic (free-floating) algae in aquatic bodies due to nutrient enrichment by sewage. It causes fish mortality and deterioration of water quality.

Question 5.
What is BOD?
Answer:
BOD (Biochemical Oxygen Demand) it is the amount of oxygen required by the microorganisms in milligram to breakdown the organic matter in water. Polluted water rises the BOD value of water. Also high BOD causes death of aquatic organisms.

Question 6.
What are the sources of radioactive pollution?
Answer:
Following are the sources of radioactive pollution

• Cosmic rays and radiations
• Nuclear weapons
• Nuclear reactors and fuels
• Radioactive isotopes
• Research and medicines.

Question 7.
Write a note on biomagnification.
Answer:
Biomagnification is defined as the increase in concentration of toxicants at successive trophic levels. Mercury and DDT are well known for biological magnification. Toxic materials cannot be metabolised or excreted. Therefore, they get accumulated in an organism and pass on to higher trophic levels, e.g. DDT accumulates in birds and disturbs calcium metabolism which result in thinning of egg shell. This results in decline of bird population.

Question 8.
Write a note on secondary treatment of sewage.
Answer:
Secondary Treatment of Sewage
1. This treatment is also known as biological treatment because it involves the use of microbes or biota for the treatment of sewage. The effluent from primary treatment is passed into large aeration tanks where it is constantly mechanically agitated and air is pumped into.

2. This air helps in the growth of useful aerobic microbes into floes (masses of bacteria associated with fungal filament to form mesh-likes structures). While growing, these microbes consume major part of the organic matter converting it into mircrobial biomass and releasing lot of minerals. This significantly reduces the BOD (Biochemical Oxygen Demand).

Question 9.
Name an industry which can cause both air and thermal pollution as well as eutrophication.
Answer:
Some of the industries that may cause air and thermal pollution as well as eutrophication are thermal power plants, refineries, smelting and metallurgical processing units, steel mills, fertiliser producing units and the industries using steam or water as coolant. The chemical released from these industries (if rich in nitrogen and phosphorus) may result in eutrophication.

Question 11.
Biological Oxygen Demand or BOD increases with increase in water pollution. In this reference, answer the questions that follows
(i) At a particular segment of the river near a sugar factory, the BOD is much higher than the normal level. What is it indicative of ?
(ii) What will happen to the dissolved oxygen and living organisms in this part of the river?
Answer:
(i) It indicates that the sugar factory releases organic waste in the water body. To degrade the organic matter, microbes utilise the dissolved oxygen in the water, thereby, reducing the levels of dissolved oxygen and increasing the BOD.
(ii) In this part of river, the dissolved oxygen will be depleted making it difficult for aquatic species to survive. It can result in death of fishes in severe cases.

Question 12.
With the help a flow chart exhibit the events of eutrophication.
Answer:
A flow chart showing eutrophication is given below

Stinking eutrophic lake with coloured and turbid water
↑
Loss of species diversity
↑
Death of aquatic animals including fish
↑
Reduced contents of dissolved oxygen
↑
Increase in organic loading of lake
↑
Death of submerged plants due to reduced light
↑
Biological enrichment of water
(algal bloom, planktonic algae and higher plants)
↑
Nutrient enrichment of water
↑
Draining of inorganic nutrients
↑
A young lake

Question 13.
How does algal bloom cause eutrophication of water body?
Answer:
Algal bloom Domestic sewage is rich in nutrients like nitrogen and phosphorus which favours the growth of algae. It causes fish mortality and deterioration of water quality.
Example of a bloom includes red tide.

Question 14.
Why is there a decline in population of fish-eating birds, when the water body is amidst agricultural fields?
Answer:
The reason for decline in fish-eating birds is biomagnification of toxic substances like DDT and other pesticides from the agricultural fields. The pesticides are applied in the fields for protection of crops.

Washed off to water bodies with irrigation water and rain and are indirectly consumed by the fishes entering the food chain. It get(s) accumulated and their concentration increases with each trophic level. Thus, on reaching fish-eating birds, their concentration will be increased many folds.

The high concentration of DDT interferes with calcium metabolism in birds and causes thinning of eggshells and their premature breaking, ultimately causing decline in bird population.

Question 15.
Discuss briefly the following
(i) Radioactive waste
(ii) Defunct ships and e-waste
Answer:
(i) Radioactive waste Radioactive waste is generated from nuclear power plants, nuclear weapon manufacturing facilities, cancer treating hospitals and research laboratories using radioisotopes in investigations. This waste is to be disposed off safely by observing the standard guideline because if it remains for a very long period and continues to emit ionising radiation, it will be extremely hazardous to health of all forms of life.

(ii) Defunct ships Old defunct ships are broken down in developing countries like India, Bangladesh and Pakistan because of cheap labour and demand for scrap metal. These ships however, possess a number of toxic materials like asbestos, lead, mercury and polychlorinated biphenyls. The people involved in ship breaking are exposed to these toxic materials and thus suffer from various diseases. The coastal areas where ship breaking is undertaken also become polluted.

Question 16.
Why does ozone hole form over Antarctica? How will enhanced ultraviolet radiations affect us?
Answer:
In Antarctica, winter months receive no sunlight and thus the temperature is extremely low (-85° C). It facilitates the formation of ice clouds which provide the catalytic surface on which the chlorine atoms react with ozone and degrade it. This happens with the return of sun to Antarctica in springs (September and October). Thus, ozone hole appears over Antarctica mostly during spring.

It is a large area of thinned ozone layer mainly over Antarctic region. At this point, depletion of ozone has occurred more as compared to the rest of the stratosphere.

Question 17.
Write short note on greenhouse effect.
Answer:
It is a naturally occurring phenomenon that is responsible for heating of earth’s surface and atmosphere due to the presence of certain gases in the atmosphere. In the absence of greenhouse gases the average temperature of earth would have been a chill-18° C reather than the present average of 15°C.

These gases radiate heat energy and a major part of which again comes to earth’s surface thus heating it up once again. This cycle is repeated again and again.
High levels of greenhouse gases (CO₂, CFCs, etc.) in the atmosphere allow the heat waves to reach earth but prevent their escape and the earth becomes warm.
This gradual continuous increase in the average temperature of surface of the earth causes global warming.

Question 18.
Write note on ozone depletion.
Answer:
It is the wearing out or reduction of the amount of ozone in the stratosphere. A number of pollutants enter into the stratosphere and deplete the ozone layer. These include CFCs, CH₄ and N₂O. CFCs are widely used as refrigerants. When they are discharged in the lower part of atmosphere, they move upward and reach the stratosphere.

In stratosphere, UV-rays act on them releasing Cl atoms. Cl degrades ozone, releasing molecular oxyen. Cl atoms are not consumed in the reaction. Hence, once CFCs are added to the stratosphere they have permanent and continuous effects on ozone levels.

Question 19.
What is ozone shield?
Answer:
Ozone layer lies in the stratosphere between 10-50 kms above the earth surface. It absorbs 90% of sun’s hazardous UV-radiation and protects plant and animal life. Thus, it is called as ozone shield.
CFC is largely responsible of ozone depletion which causes skin cancer, cataract and weaken immune system.

Question 20.
What is the common household source of CFCs? How these gases affect the ozonalayer?
Answer:
CFCs are widely used as refrigerants. When they are discharged in the lower part of atmosphere, they move upward and reach the stratosphere. In stratosphere, UV-rays act on them releasing Cl atoms. Cl degrades ozone releasing molecular oxygen. Cl atoms are not consumed in this reaction. Hence, once CFCs are added to the stratosphere, they have permanent and continuous effects on ozone levels.

Question 21.
Write, what was the percentage of forest cover of India at the beginning and at the end of 20th century. How different it is from the one recommended by National Forest Policy?
Answer:
In the beginning of the 20th century, the forest cover was about 30% while towards its end it reduced to only 19.4%. The National Forest Policy of India – recommends approximately 67% forest cover for hilly regions including himalayas, while 33% for plains. However, the situation is contrastingly different.

Question 22.
Name any one greenhouse gas and its possible source of production on a large scale. What are the harmful effects of it?
Answer:
Carbon dioxide is a major greenhouse gas. Various human activities such as combustion of fossil fuels, electricity generation, transportation and industries are sources of its large scale production. Excess of CO₂ is harmful and considered as a pollutant. It is because it traps longer wavelength IR radiations reflected by earth’s surface, thus causing global warming.

Question 23.
It has been recorded that the temperature of the earth’s atmosphere has increased by 0.6°C.
(i) What has caused this increase?
(ii) Explain its consequences.
Answer:

• Increase in the level of greenhouse gases (CO₂,CFCS, etc.) in the atmosphere allow the heat waves to reach earth but prevent their escape and thus, the earth becomes warm.
• Effects of increased temperature are
  • Leads to deleterious changes in environment, resulting into odd climatic changes such as El Nino effect.
  • Melting of polar ice caps which will cause the rise in sea level and many coastal areas may also get submerged.

Question 24.
How does Jhum cultivation promote deforestation?
Answer:
Forests are the providers of timber, fuel wood and other products. Forests also provide habitat to different groups of plants and animals. Forests are cut down for various purposes. Some of the reasons are as follows

• Urbanisation
• Overgrazing by animals
• Forest fires
• Demand of wood and other forest products
• Jhum cultivation.

Slash and bum agriculture is known as Jhum Cultivation in the North-Eastern states of India. In this method, the farmers cut down the trees of the forest and burn the plant remains.
The ash is used as a fertiliser and the land is then used for farming or cattle grazing. After cultivation, the area is left for several years so as to allow its recovery.
This same process is repeated at some other area. In initial days, there was ample recovery time, but now-a-days with increasing population and repeated cultivation, this recovery phase is done away with, resulting in deforestation.

Question 25.
How can slash and burn agriculture become environment friendly?
Answer:
Slash and burn agriculture can become environment friendly if

• small widely scattered plots are used for cultivation, so that the forest ecosystem will not suffer damage.
• crop rotation is used so that soil does not loose its entire fertility.
• keeping cropping period small and follow up (unplanted) period longer.

Question 26.
What is the main idea behind ‘Joint Forest Management Concept’ introduced by the Government of India?
Answer:
The main idea behind joint forest management concept introduced by the Government of India was involving the local communities in forest conservation. This concept was adopted considering the extraordinary courage and dedication the local people showed in protecting the wildlife through the movements like Bishnoi’s movement in Jodhpur and Chipko Movement in Garhwal Himalayas.

Question 27.
Write a note on deforestation and enumerate its consequences.
Answer:
It is the conversion of forested areas to non-forested areas. Almost 40% forests have been lost in the tropics, compared to only 1% in the temperate region.
According to a report by the World Commission on Forests and Sustainable Development (WCFSD), from 6 billion hectares, 8000 years ago, there is a decline of 3.6 billion hectares in 1999 of the forest cover. Similar results were also given by the Food and Agriculture Organisation (FAO).
In India, at the beginning of the 20th century, forest covered area was about 30% of land, whereas by the end of the century, it reduced to 19.4%. This shows the alarming condition of our country.

The loss of trees due to their increased cutting is note worthy. Some of the effects due to deforestation are as follows

• Increased levels of CO₂ concentration in atmosphere.
• Loss of biodiversity due to habitat destruction.
• Disturbed hydrologic cycle.

The Andaman and Nicobar islands are the world’s first evergreen forests. The forests also comprise of local comminutes like the Great Andamanese, the Onge, the Jaracuas and the Sentinelese. But, now their population is decreasing 340 km long. Andaman Trunk road was constructed which went through the evergreen forests.
This resulted in clearing of the forest and the tribal communities like Jaracuas original way of life was eroded.

Question 28.
Why has the National Forest Commission of India recommended a relatively larger forest cover for hills than for plains?
Answer:
It is our moral duty to protect, restore and conserve/preserve the forests as they are highly beneficial for mankind.
In India, around 30% of land was covered by forest in early 20th century, which was reduced to 18-19% by the year 2000. National Forest Commission of India (1988) recommended a relatively large forest cover, i.e. 67% for the hills and 33% for the plains. Recommendation of a large forest area for hills is due to its properties like checking soil erosion, percolation and recharging groundwater, checking landslide and other natural calamities and to maintain the original flora and fauna of hills.

Question 29.
How have human activities caused desertification? Explain.
Answer:
The human activities like deforestation, over-cultivation, unrestricted grazing, poor irrigation practices, result in arid patches of land (deforestation).
When these large barren patches extend and remain unattended for long, a desert is created. Because the formation of fertile top layer of soil takes millions of years, desertification easily takes over.

Question 30.
What do you know about Chipko Movement?
Answer:
Chipko Movement happened in 1974, when local women in Garhwal district of India showed enormous bravery in protecting trees from the axe of contractors by hugging them. This movement was world famous and was globally supported.

Question 31.
Discuss the causes and effects of global warming. What measures need to be taken to control global warming?
Answer:
For causes, effects and control measures of global warming.
It has been estimated by computer application studies that there may be a rise of 3°C by the year 2100 on an average.
The major effects of global warming include

1. Climate Earth temperature has increased by 0.6°C during past century, most of it in last three decades. This increased temperature caused changes in precipitation patterns.
2. Glaciers and ice caps Scientists have proposed that this rise in temperature causes deleterious changes in the environment, resulting in odd climatic changes. Thus, leading to melting of the polar ice caps and Himalayan snow caps.
3. Animals and humans The new warmer temperature conditions lead to eruption of diseases in animals and thousands of species will become extinct in a very short period of time. People from coastal areas will start migrating due to climate change.
4. Ocean and coasts The increase in temperature causes melting of polar ice caps and glaciers. This will result in the rise of ocean water level. The increased level of ocean water will cause the submerging of many island nations and coastal cities. The high temperature will cause accelerated vanishing of coral reefs.
5. Water and agriculture The increased temperature will cause decreased productivity in agricultural practice.

Question 32.
Discuss briefly the following
(i) Greenhouse effect
(ii) Ultraviolet-B
Answer:
(i) It is a naturally occurring phenomenon that is responsible for heating of earth’s surface and atmosphere due to the presence of certain gases in the atmosphere. In the absence of greenhouse gases the average temperature of earth would have been a chill-18° C reather than the present average of 15°C.
These gases radiate heat energy and a major part of which again comes to earth’s surface thus heating it up once again. This cycle is repeated again and again.
High levels of greenhouse gases (CO₂, CFCs, etc.) in the atmosphere allow the heat waves to reach earth but prevent their escape and the earth becomes warm.
This gradual continuous increase in the average temperature of surface of the earth causes global warming.

(ii) Ultraviolet-B It is an electromagnetic radiation which has a shorter wavelength than visible light.
It is a harmful radiation that comes from sunlight and penetrates through the ozone hole to the . earth’s surface. It causes many health hazards in humans. UV-B damages DNA and activates the process of skin ageing. It also causes skin darkening and skin cancer. High levels of UV-B cause corneal cataract in human beings.

Question 33.
What depletes ozone in the stratosphere? How does this affect human life?
Answer:
Ozone in the stratosphere is depleted by CFCs, i.e chlorofluorocarbons, released primarily from refrigerators and other industrial emissions.
This affects the human life as it leads to more exposure of UV-radiation, which is considered to be harmful for health. For effects of UV-radiation on human health.
These radations can cause skin cancer, weaker immunity cataract and loss of plant productivity. The thickness of ozone in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson Units (DU).

Differentiate between the following (for complete chapter)

Question 1.
Biomagnification and Eutrophication.
Answer:
Differences between biomagnification and eutrophication are as follows

Biomagnification	Eutrophication
It is the progressive increase in concentration of non-biodegradable substances in the food chain.	It is the enrichment of the water body with plant nutrients like fertilisers from outside.
It is found in all types of ecosystems.	It is found only in aquatic ecosystem and leads to organic loading.
It leads to toxicity in higher order consumers.	It leads to death of most animals and plants in the affected water body.

Question 2.
Deforestation and Reforestation.
Answer:
Differences between deforestation and reforestation are as follows

Deforestation	Reforestation
It is indiscriminate cutting down of trees for human usage.	It involves the planting of new trees in place of the ones cut down.
This reduces the green cover of the particular area.	It is to increase the green cover of a deforested area.
It leads to decline in habitats and biodiversity.	It is done in order to safeguard biodiversity.

Question 3.
Point and Non-point sources of water pollution.
Answer:
Differences between point source of water pollution and non-point source of water pollution are as follows

Point source of water pollution	Non-point source of water pollution
It is pollution caused by discharge of effluents at one point.	It is pollution caused by discharge of pollutants over a wide area.
Due to large scale entry of pollutants at one point the contamination and harmful effect on quality of water is maximum.	There is some dilution of the effect of pollutants due to large size of area.
Treatment plant can be installed in the area of flow of effluents.	Treatment plant is useless for this type of pollution.
Other type of control measures are not required.	Control measures are required on a large scale for non-liberation of pollutants.

Question 4.
Biodegradable pollutants and Non-biodegradable pollutants.
Answer:
Differences between biodegradable pollutants and non-biodegradable pollutauts are as follows

Biodegradable pollutants	Non-biodegradable pollutants
They are those pollutants which are decomposed and degraded by microbes.	The pollutants are not decomposed by microbes.
The pollutants are degraded quite rapidly.	They are degraded very slowly.
Biodegradable pollutants do not pile up.	They often get accumulated.
They can be used to produce energy, manure compost and biogas.	Some of the pollutants of properly separated can be recycled others are not manageable.
They become part of rapid-turnover in biogeochemical cycles.	Many of them do not enter biogeochemical cycles. Others are very slow and often toxic.
Examples garbage, sewage, livestock.	Examples DDT, BHC, plastics, polyethylene, cans, broken glass, etc.

Question 5.
Herbicides and Insecticides
Answer:
Differences between herbicides and insecticides are as follows

Herbicides	Insecticides
These are a type of pesticides used to kill undesirable plants or weeds.	These are type of pesticides that are used to specifically target and kill insects.
Some herbicides kill all the plants they come in contact with, while others are designee to target one species.	The targets are fixed, e.g. snail bait, ant killer and i wasp killer.

Question 6.
Acid rain and Global warming.
Answer:
Difference between acid rain and global warming are as follows

Acid rain	Global warming
Acid rain is the name given to rain, snow or sleet contaminated with acid substance. This occurs when the rain water combines with nitric and sulphuric acids.	Global warming is when the earth’s temperature rises. It happens when carbon dioxide, water vapour, nitrous oxide and methane trap heat and light from the sun in the earth’s atmosphere, which increases the temperature.

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 16 Biodiversity and its Conservation and Environment Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 16 Biodiversity and its Conservation

Biodiversity and its Conservation Class 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
Indian Giant squirrel in endemic to
(a) Uttar Pradesh
(b) West Bengal
(c) Madhya Pradesh
(d) Manipur
Answer:
(c) Madhya Pradesh

Question 2.
Species richness in any habitat is related to
(a) genetic diversity
(b) species diversity
(c) ecosystem diversity
(d) None of these
Answer:
(b) species diversity

Question 3.
As per IUCN nomenclature, diversity of species across a wide geographical range is called
(a) alpha
(b) beta
(c) gamma
(d) community
Answer:
(c) gamma

Question 4.
Biodiversity is rich in tropics because of
(a) high humidity
(b) stable climate
(c) older community
(d) All of these
Answer:
(d) All of these

Question 5.
The organisation which publishes the Red List of species is
(a) WWF
(b) ICFRE
(c) IUCN
(d) UNEP
Answer:
(c) IUCN

Question 6.
Red Data List was initiated in
(a) 1859
(b) 1963
(c) 1985
(d) 1977
Answer:
(b) 1963

Question 7.
As per the Red List published by the World conservation union, Indian Cheetah is categorised as …………. .
(a) vulnerable
(b) extinct
(c) critically endangered
(d) endangered
Answer:
(b) extinct

Question 8.
Diversity at the level of community and ecosystem is
(a) α – diversity
(b) β – diversity
(c) γ – diversity
(d) All of these
Answer:
(b) β – diversity

Question 9.
Red Data Book is mainted by
(a) CITES
(b) WCU
(c) CBD
(d) IUPAC
Answer:
(b) WCU

Question 10.
Which one is endangered species?
(a) Asiatic lion
(b) Sparrow
(c) Elephant
(d) Dodo
Answer:
(a) Asiatic lion

Question 11.
Which one of the following is not included under in situ conservation?
(a) Wildlife sanctuary
(b) Zoological garden
(c) Biosphere reserve
(d) National park
Answer:
(b) Zoological garden

Question 12.
Conservation and maintenance of wildlife within the natural ecosystem is
(a) in situ conservation
(b) ex situ conservation
(c) botanical gardens
(d) All of the above
Answer:
(a) in situ conservation

Question 13.
In a national park, protection is provided to
(a) entire ecosystem
(b) only fauna
(c) only flora
(d) Both (b) and (c)
Answer:
(a) entire ecosystem

Question 14.
In which zone, limited permitted?
(a) Core zone
(b) Buffer zone
(c) Manipulation zone
(d) Restoration zone
Answer:
(b) Buffer zone

Question 15.
Ramsar convention was held in
(a) India
(b) Iran
(c) Indonesia
(d) Isroel
Answer:
(b) Iran

Question 16.
Bandipur national park is situated in
(a) Kerala
(b) Odisha
(c) Karnataka
(d) Rajasthan
Answer:
(c) Karnataka

Question 17.
The objective of ‘Ramsar convention’ was
(a) forest conservation
(b) wildlife conservation
(c) wetland conservation
(d) biodiversity conservation
Answer:
(c) wetland conservation

Fill in the blanks

Question 1.
Diversity within a community is ……….. .
Answer:
α-diversity.

Question 2.
…………, a struggling shrub from tropical America was introduced as ornamental plant in India has become invasive in the wild.
Answer:
Lantana

Question 3.
A taxon facing high risk of extinction in the wild is ………… .
Answer:
vulnerable

Question 4.
Beaver is a ……….. species
Answer:
keystone

Question 5.
In India hotspots include Western Ghats and ………… .
Answer:
Eastern Himalayas.

Question 6.
The Earth Summit was held in …………. 1992.
Answer:
Brazil

Question 7.
The outer part of biosphere reserve is called ………… .
Answer:
buffer zone.

Question 8.
Wildlife Protection Act was enacted in the year ………. by Government of India.
Answer:
1972

Question 9.
Panna biosphere reserve is located in ……….. .
Answer:
Madhya Pradesh

Question 10.
Private ownership is not permitted in ………… .
Answer:
National Parks

Correct the statement, if required by changing the underlined word

Question 1.
Species diversity decreases as we move away from the equator.
Answer:
Correct statement

Question 2.
Eichhomia called as ‘Terror of Bengal’ is a keystone species.
Answer:
alien species.

Question 3.
The number of species per unit area is ß-diversity.
Answer:
species richness

Question 4.
Zoos, botanical gardens, culture collections are types of ex situ biodiversity conservation.
Answer:
in situ

Question 5.
Exploitation of soil and flora is done in a wildlife sanctuary.
Answer:
Conservation of fauna and flora

Question 6.
The transitional zone of a biosphere reserve is strictly protected to maintain the ecological diversity and integity.
Answer:
core zone

Question 7.
In situ conservation is the conservation of biological diversity outside the boundaries of their natural habitats.
Answer:
ex situ conservation

Express in one or two words

Question 1.
Diversity among individuals of a species.
Answer:
Genetic diversity

Question 2.
The extinction of these species reduces abundance of other species in the community
Answer:
keystone species.

Question 3.
The variety of species within a community.
Answer:
Species diversity

Question 4.
The scientist who developed the concept of hotspots of biodiversity?
Answer:
Norman Myers.

Question 5.
A protected area dedicated to animals life only.
Answer:
Wildlife sanctuaries.

Short Answer Type Questions

Question 1.
Write briefly about the three levels of biological diversity.
Answer:
There are three levels of biological diversity

• Genetic diversity Variations in the genetic composition of individuals within a species or. among species is known as genetic diversity.
• Species diversity It pertains to the variety of species present in a particular area or ecosystem.
• Ecosystem diversity It refers to diversity of habitats, e.g. terrestrial and aquatic ecosystem.

Question 2.
State the importance of species diversity to the ecosystem.
Answer:
The importance of species diversity to the ecosystem are

• Increased biodiversity provides resistance to the ecosystem against natural disasters.
• Ecosystem with more species shows more yields and greater productivity with variation of biomass.
• Community with more species generally tends to be more stable than those with less species.

Question 3.
Species diversity decreases as we move away from the equator towards the poles. What could be the possible reasons?
Answer:
Species diversity decreases as we move towards the poles, because

1. temperature decreases and conditions become harsh.
2. both the amount and intensity of solar radiation decreases.
3. vegetation decreases.
4. less resources available to support species. Speciation is generally a function of time and environmental stability, so if conditions are too harsh, it is difficult for the species to survive and adapt. This results in decrease in biodiversity towards the poles.

Question 4.
Explain giving three reasons why tropic show, greatest levels of species diversity.
Or
Give three hypothesis for explaining, why tropics show greatest level of species richness.
Answer:
It is the variety in the number and richness of a species of a region. Sometimes, a species remains confined to a particular area and is found only in that area. Such species are said to be endemic, e.g., Indian giant squirrel is endemic to Panchmarhi hills in Madhya Pradesh.

The IUCN (International Union for Conservation of Nature and Natural Resources) recognises three types of species diversity, i.e.

1. Alpha (α) diversity It refers to the variety of species within a community. It is also referred to as species richness, i.e., the number of species per unit area.
2. Beta (β) diversity It refers to the diversity of species among communities.
3. Gamma (γ) diversity It refers to the diversity of species across a wide geographical range.

Question 5.
How is biodiversity important for ecosystem functioning?
Answer:
Nature always key a check on these activities to maintain a state of equilibrium (homeostasis), which further helps in the sustainable development of resources. However, overexploitation of biolgical resources by humans leads to destabilisation of ecosystem balance.
For example,

1. Decreased flora of an area leads to CO₂ increase in the atmosphere which causes temperature elevation of that area.
2. Increased carnivore population decreases the . herbivore population by predation which then increase the vegetation.
3. Declined population of microflora prevents the recycling between complex organic matter and simple inorganic matter.

Question 6.
What is a keystone species? Give an example.
Answer:
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species are important in maintaining the structure of an ecological community by affecting other organisms in an ecosystem and helping to determine the abundance of other species in the community, e.g. beaver (a mammal) who creates dams, modifies nutrient cycling, influences decomposition dynamics which ultimately influences the plants and animals of that area.

Question 7.
Write an account on loss of biodiversity in the world.
Answer:
The loss of biodiversity is a global crisis. Extinction of species is a natural phenomenon aided by the physical changes in the environment. However, the accelerated rates of species extinctions, that the world is facing now are largely due to human activities.

Till now, five episodes of mass extinction of species have occured in the history of biological evolution. The sixth episode of extinction of species however, is credited to human activities, which otherwise would not have occurred.

Question 8.
How does habitat fragmentation cause depletion of biodiversity?
Answer:
When large habitats are broken up into small fragments due to the various human activities, mammals and birds requiring large territories and certain animals with migratory habits are badly affected, leading to their population decline.

Question 9.
Briefly classify the extinction processes.
Answer:
The extinction of species is a natural process. Many species have disappeared and new ones have evolved to take over their place. There are three types of extinction processes

1. Natural extinction When there is change in environmental conditions, certain species disappear and others, (which are more adapted to changed conditions) take their place. This loss of species that occurred in the geological past at a very slow rate is known as natural extinction.
2. Mass extinction There have been several periods in the earth’s geological history when large number of species become extinct due to catastrophes, e.g. extinction of dinosaurs in end cretaceous period.
3. Anthropogenic extinctions Recently more number of species is disappearing from the face of the earth due to human activities. Man-made mass extinction represents a very severe depletion of biodiversity.

Question 10.
Since the origin of life on earth, there were five episodes of mass extinction of species.
(i) How is the ‘sixth extinction’, presently in progress, different from the previous episodes?
(ii) Who is mainly responsible for the ‘sixth extinction’?
(iii) List any four points that can help to overcome this disaster.
Answer:
(i) The current species extinction rate are estimated to be 100-1000 times faster than in pre-human times.
(ii) Human activities.
(iii) To prevent sixth extinction to take place we should

• prevent habitat loss and fragmentation.
• check over exploitation.
• prevent alien species invasion.
• prevent coextinction.
• conservation and preservation of species

Question 11.
How is diversity at all levels generally conserved?
Ans.
Diversity is recognised by gene pool, species and biotic community. The ecosystem is affected by changes due to the pollution, climatic changes and overexploitation, etc. There is need to prevent further destruction or degradation of habitats in order to conserve the biodiversity. These are on site (in situ) and off site (ex situ) strategies of conservation. Protected areas like national parks, sanctuaries and biosphere reserves also helps to maintain diversity.

Question 12.
State the significances of ex situ conservation.
Answer:
Ex situ conservation is outside conservation strategy, in which zoos help in captive breeding of organisms which are endangered, whereas botanical gardens have seed gene banks, tissue culture labs and other technologies for storing and growing germplasm.

Question 13.
There are many animals that have become extinct in the wild, but continue to be maintained in zoological parks.
(i) Which type of biodiversity conservation is observed in this case?
(ii) Name any other two ways, which help in this type of conservation?
Answer:
(i) It is an example of ex situ (off site) conservation. In this approach, threatened plants and animals are taken out of their natural habitat and placed in suitable settings and given special care.
(ii) Ciyopreservation and tissue culture are two ways that help in ex situ conservation.

Question 14.
Which type of conservation measures, in situ or ex situ will help the larger number species to survive? Explain.
Answer:
Out of the two, the in situ conservation measures will help in the survival of larger number of species.
In situ is onsite conservation, which implies that species are conserved in their natural habitat.
To conserve species in their natural habitat, the entire ecosystem has to be conserved, which include other organisms, biotic and abiotic component of the ecosystem associated with the target species.
Hence, in situ conservation helps in the survival of larger number of species.

Question 15.
What do you mean by national park?
Or
Write a note on national park.
Answer:
A national park is an area dedicated to conserve the environment, natural and historical objects and the wildlife therein. It also aims to provide enjoyment in such a manner and by such a means that will leave them unimpaired for the enjoyment of the future generations, e.g. Jim Corbett National Park, Uttarakhand.

Question 16.
What are hotspots of biodiversity?
Or
Write a note on biodiversity hotspots.
Answer:
Hotspots are areas that are extremely rich in species diversity, have high endemism and are under constant threat of extinction. Out of the total hotspots of the world, three are found in India.
They are Eastern Himalayas which extends from North-Eastern India to Bhutan, Western Ghats which include forests that lie in the states such as Karnataka, Maharashtra and Tamil Nadu and Indo-Burma region.

Question 17.
What is biosphere reserve? Mention its zones.
Or
Briefly discuss the four zones of biosphere reserve.
Answer:
A biosphere reserve is a specified area in which multiple use of the land is permitted. It is divided into four stones
(i) Core zone It is the innermost and legally protected where no human activity is allowed.
(ii) Buffer zone Here, limited human activity is allowed, like sustainable and recreational activities.
(iii) Transitional zone Anthropogenic activities like research and sustainable development is allowed.
(iv) Zone of human encroachment Here, normal anthropogenic activities are allowed.

Differentiate between the following (for complete chapter)

Question 1.
Sanctuary reserve and Biosphere reserve.
Answer:
Differences between sanctuary reserve and biosphere reserve are as follows

Sanctuary reserve	Biosphere reserve
Attention is not given to biotic community, i.e. conservation is species oriented.	Attention is focused on biotic community as a whole, i.e. conservation is ecosystem oriented.
Limits are not circumscribed.	Boundaries are circumscribed by the state legislation.
There occurs limited biotic interference.	There occurs no biotic interference except in buffer zone.
Tourism in a sanctuary is permissible.	Tourism is not permissible inside biosphere reserve
Research and scientific management are lacking.	Research and scientific management are carried out.
Proper attention is not given to gene pool conservation of economic species, particularly in plants.	Due attention is given to the conservation of plants as well as animal species.

Question 2.
Beta (β) diversity and Gamma (γ) diversity.
Answer:
Differences between beta diversity and gamma diversity are as follows

Beta (β) diversity	Gamma (γ) diversity
It is diversity of species among communities.	It refers to the diversity of species across a wide geographical range.
It develops due to change in habitat of community along environment gradients.	It represents the total richness of species in all the habitats found within a region, geographical areas or landscape.
When the difference of species between the habitats is greater, it represents greater Beta-diversity.	When each habitat has a unique biota, gamma diversity is equal to average alpha diversity multiplied by the number of such habitats.

Question 3.
Species diversity and Ecological diversity.
Answer:
Differences between species and ecological diversity are as follows

Species diversity	Ecological diversity
It is related to the number, type and distribution of species found in given area.	It is the variety of ecosystems in a biosphere.
It is the trait of the community.	It is the diversity at the level of communities and ecosystems of region.
It is affected not only by the number of individuals, but also by the heterogeneity of the sample.	It is affected directly by the environment.

Question 4.
Alpha (α) diversity and Beta (β) diversity
Answer:
Differences between alpha and beta diversity are as follows

Alpha (α) diversity	Beta (β) diversity
It is the variety of species within a community.	It is diversity of species between communities.
It was defined by Whittaker as the species richness of a place.	It was defined by Whittaker as the extent of species replacement or biotic change along environmental gradients.
A community will have a high alpha diversity, when there is a high number of species and their abundance are much similar.	Beta diversity measures the turnover of species between two sites in terms of gain or loss of species.

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 15 Ecosystem and Environment Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 15 Ecosystem

EcosystemClass 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
Biotic components include
(a) producers, consumers and decomposers
(b) producers and consumers
(c) Both (a) and (b)
(d) None of the above
Answer:
(a) producers, consumers and decomposers

Question 2.
The non-green plants are as important as green plants because they
(a) cause human diseases
(b) cause diseases of other plants
(c) are useful in several industries
(d) bring about decomposition of dead animal and plant remains
Answer:
(d) bring about decomposition of dead animal and plant remains

Question 3.
Primary consumers are always
(a) producers
(b) carnivores
(c) herbivores
(d) omnivores
Answer:
(c) herbivores

Question 4.
Man is ………… .
(a) herbivorous
(b) carnivorous
(c) omnivorous
(d) producers
Answer:
(c) omnivorous

Question 5.
Secondary producers are
(a) herbivores
(b) producers
(c) carnivores
(d) None of these
Answer:
(d) None of these

Question 6.
Which of the following is an abiotic component of ecosystem?
(a) Bacteria
(b) Humus
(c) Plants
(d) Fungi
Answer:
(b) Humus

Question 7.
Decomposers are generally
(a) green plants
(b) phytoplanktons
(c) insects
(d) microorganisms
Answer:
(d) microorganisms

Question 8.
Abiotic components of an ecosystem include
(a) producers, consumers and decomposers
(b) producers and consumers
(c) only producers
(d) None of the above
Answer:
(d) None of the above

Question 9.
An ecosystem is not a /an
(a) open system
(b) closed system
(c) variable system
(d) None of the above
Answer:
(b) closed system

Question 10.
Trophic levels in ecosystem are formed by
(a) only bacteria
(b) only plants
(c) only herbivores
(d) organisms linked in food chain
Ans.
(d) organisms linked in food chain.

Question 11.
Detritus food chain begins with
(a) virus
(b) bacteria
(c) protozoan
(d) algae
Answer:
(b) bacteria

Question 12.
Which one of the following has the largest population in food chain?
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers
Answer:
(d) Decomposers.
As, they include microorganisms, they form largest population in a food chain and decompose dead plants and animals.

Question 13.
The second trophic level in a lake is ………….. .
(a) phytoplanktons
(b) zooplanktons
(c) benthos
(d) fishes
Answer:
(b) Zooplanktons.
They are primary consumers in an aquatic food chain who feed upon phytoplanktons.

Question 14.
A food chain can have trophic levels
(a) one
(b) two
(c) three
(d) multiple
Answer:
(d) multiple

Question 15.
Who proposed the concept of ecological pyramid?
(a) Odum
(b) Elton
(c) Tansley
(d) Clements
Answer:
(b) Elton.

Question 16.
Primary succession is development of communities on
(a) cleared forest area
(b) newly exposed habitat
(c) pond filled after a dry season
(d) freshly harvested crop field
Answer:
(b) newly exposed habitat

Question 17.
Lichen is pioneer in which succession?
(a) Hydrosere
(b) Lithosere
(c) Psammosere
(d) Halosere
Answer:
(b) Lithosere

Question 18.
Plant succession in a saline habitat is called
(a) hydrosere
(b) halosere
(c) psammosere
(d) xerosere
Answer:
(b) halosere

Question 19.
The first species that establishes itself in a barren habitat due to succession is called
(a) climax
(b) migrant
(c) colony
(d) pioneer
Answer:
(d) pioneer

Question 20.
When propagating units like seeds and spores enter a barren area to initiate the process of succession, it is called
(a) nudation
(b) reaction
(c) ecesis
(d) migration
Answer:
(c) ecesis

Question 21.
The rate of release of nutrients into atmosphere is regulated by
(a) temperature
(b) soil nature
(c) pH
(d) All of the above
Answer:
(d) All of the above

Question 22.
Weathering of rocks makes phosphorus available first to
(a) producers
(b) decomposers
(c) consumers
(d) None of the above
Answer:
(a) producers

Fill in the blanks

Question 1.
Plants are called as ……….. because they fix carbon dioxide.
Answer:
autotrophs

Question 2.
In an aquatic ecosystem, the limiting factor for the productivity is …….. .
Answer:
sunlight

Question 3.
Decomposers are generally ……… (green plants, microorganisms, phytoplanktons, insects)
Answer:
microorganisms

Question 4.
A detrivore is animal feeding on …………… .
Answer:
dead matter

Question 5.
Productivity is expressed in terms of …………… .
Answer:
g^-2 yr^-1 (kcal m^-2)yr^-1

Question 6.
Amount of energy transferred from one trophic level to next is ………. .
Answer:
10%.

Question 7.
Tip of an ecological pyramid is occupied by ………. .
Answer:
carnivores.

Question 8.
In an ecosystem dominated by trees, the pyramid of number is ………. type.
Answer:
inverted.

Question 9.
Green plants constitute ………….. trophic level.
Answer:
First

Question 10.
………… represents sedimentary type of nutrient cycle.
Answer:
Phosphorus.

Question 11.
In ……….. succession, dominant organisms are autotrophs.
Answer:
autotrophic

Question 12.
The individual transitional communities are called ………. .
Answer:
serai

Correct the statement if required, by changing the underlined word

Question 1.
The term ecosystem was proposed by Odum.
Answer:
Tansley

Question 2.
The two components of an ecosystem are plants and animals.
Answer:
biotic and abiotic.

Question 3.
Carnivores are always primary consumers.
Answer:
Herbivores

Question 4.
The raw material for decomposition is called vermicompost.
Answer:
detritus

Question 5.
Net primary productivity is GPP + R.
Answer:
GPR-R

Question 6.
Out of the total solar energy, PAR is only 1-5%.
Answer:
50%

Question 7.
Phytoplanktons occupy more than one trophic level in pond ecosystem.
Answer:
Fishes.

Question 8.
Pyramid of energy is always inverted.
Answer:
upright.

Question 9.
Pyramid of energy is always inverted.
Answer:
Always upright

Question 10.
Flow of energy declines as it passes from lower to higher trophic level. This is explained by first law of thermodynamics.
Answer:
It is correct.

Question 11.
Plant succession in a sandy area is lithosere.
Answer:
psammosere

Question 12.
The pioneer community in hydrosere is submerged plants.
Answer:
phytoplanktons

Question 13.
Climate control comes under supporting ecosystem services.
Answer:
Primary productivity

Question 14.
The first species that establishes itself in a barren habitat due to succession is called migrant.
Answer:
pioneer species

Question 15.
Lichens and mosses are the part of halosere.
Answer:
xerosere

Express in one or two words

Question 1.
What is the creating force of an ecosystem?
Answer:
Solar energy.

Question 2.
What type of ecosystem is represented by pond?
Answer:
Freshwater ecosystem.

Question 3.
Name the common detritivores in an ecosystem.
Answer:
Earthworms

Question 4.
Name the two basic categories of an ecosystem.
Answer:
Natural and Artificial ecosystem

Question 5.
Name the largest decomposers of forest floor.
Answer:
Microorganisms

Question 6.
Name the term used for rate of storage of organic matter not used by heterotrophs.
Answer:
Gross primary productivity

Question 7.
Name any two organisms, which can occupy more than one trophic level in an ecosystem.
Answer:
Human beings and birds (e.g. sparrow).

Question 8.
State, what does standing crop of a trophic level represent?
Answer:
Standing crop represents total amount of living matter or organic matter present in an ecosystem in an unit area and at a specific time.

Question 9.
List any two ways of measuring the standing crop of a trophic level.
Answer:
Two ways of measuring the standing crop of a trophic level are

• Biomass of living organisms.
• Number in an unit area.

Question 10.
Expand PAR.
Answer:
Photosynthetically Active Radiation

Question 11.
What is the starting point of a grazing food chain and of a detritus food chain?
Answer:
Producers and dead organic matter, respectively.

Question 12.
Which is the major reservoir of carbon on earth?
Answer:
Ocean.

Question 13.
Under what conditions would a particular stage in the process of succession revert back to an earlier stage?
Answer:
Natural or human induced disturbances like fire, deforestation, etc.

Question 14.
Give one examples of xerarch succession.
Answer:
Sand deserts and rock deserts (as there is no water and the substratum does not absorb rainwater).

Question 15.
How much of carbon is dissolved in the oceans?
Answer:
71%

Question 16.
Name the two forms of reservoir of carbon, that regulate the ecosystem carbon cycle.
Answer:
ocean and fossil fuel

Question 17.
How much carbon is fixed in the biosphere through photosynthesis annually?
Answer:
4 × 10¹³ kg

Question 18.
What do you understand by the term serai stage?
Answer:
The individual transitional communities are termed as serai stage.

Short Answer Type Questions

Question 1.
Write a note on ecosystem.
Answer:
Ecosystem is considered as an interactive system, where biotic and abiotic components interact with each other via energy exchange and flow of nutrients. An ecosystem can be either natural or artificial. Natural ecosystems These are capable of maintaining and operating themselves, without the interference of man. They are further classified as

Artificial ecosystems These are maintained and manipulated by man for different purposes, e.g. cropland, aquarium, etc.

Question 2.
Is an aquarium a complete ecosystem?
Or
Can an aquarium be considered a complete ecosystem?
Answer:
Yes, aquarium is a man-made ecosystem (artificial). If an ecosystem possesses all physical and biological components, then it is said to be complete.
Since, aquarium has biotic components (plants and fishes) and abiotic components (air and water) required for survival of fishes so, it is a complete ecosystem.

Question 3.
Apart from plants and animals, microbes form a permanent biotic component in an ecosystem.
While plants have been referred to as autotrophs and animals as heterotrophs, what are microbes referred to as?
Or
How do these microbes fulfil their energy requirements?
Answer:
Microbes are referred to as heterotrophs and saprotrophs. They fulfil their energy requirement by feeding on dead remains of plants and animals through the process of decomposition.

Question 4.
How are productivity, gross primary productivity, net primary productivity and secondary productivity interrelated?
Answer:
A constant input of solar energy is the basic requirement’ for any ecosystem so that the living organisms can survive, grow (make new cells) and maintain their internal orgnisation. The rate of synthesis of energy containing organic matter or biomass per unit area in unit time is called its productivity. It is expressed in terms of g^-2yr^-1 or (kcal m^-2) yr^-1. Productivity of an ecosystem can be categorised as primary and secondary productivity.

Primary Productivity:
It is the amount of biomass or organic matter produced per unit area over a time period by plants due to photosynthesis. It is expressed in terms of weight (g^-2d^-1) or energy (kcal m^-2).
The primary productivity has two aspects as discussed below

Gross Primary Productivity (GPP):
It is the total amount of produced organic matter during photosynthesis. A considerable amount of GPP is utilised or lost by plants in respiration.

Net Primary Productivity (NPP)
It is the available biomass for the consumption by heterotrophs (herbivores and decomposers). It is actually the amount of energy left in the producers after the utilisation of some energy during respiration. Thus, Gross Primary Productivity (GPP) minus the Respiration Losses (R) gives the Net Primary Productivity.

GPP – R = NPP where, R = Respiration losses.
Net primary productivity differs in different communities of plants, e.g.

• In terrestrial community, GPP is 2.7 times of NPP.
• In ocean community, GPP is 1.5 times of NPP.

Secondary Productivity:
It is the rate of assimilation and formation of new organic matter by consumers. It is small as compared to primary productivity and tends to decrease with an increase in the trophic level.

Question 5.
Primary productivity varies from ecosystem to ecosystem. Explain.
Answer:
Primary productivity varies from ecosystem to ecosystem because it depends on the plant species inhabiting the area and their photosynthetic activity. It also depends on various environmental factors like-light, temperature, rain, etc., and nutrient availability which varies in different ecosystems.

Question 6.
(i) What is primary productivity? Why does it vary in different types of ecosystems?
(ii) State the relation between gross and net primary productivity.
Answer:
(i) RIt is the amount of biomass or organic matter produced per unit area over a time period by plants due to photosynthesis. It is expressed in terms of weight (g^-2d^-1) or energy (kcal m^-2).
Primary productivity varies from ecosystem to ecosystem because it depends on the plant species inhabiting the area and their photosynthetic activity. It also depends on various environmental factors like-light, temperature, rain, etc., and nutrient availability which varies in different ecosystems.

(ii) The relation between the gross and net primary productivity can be shown as P_n = P_g – R
where, P_n = Net Primary Productivity (NPP)
P_g = Gross Primary Productivity (GPP)
R = Respiration

Question 7.
Which of the following ecosystems will be more productive in terms of primary productivity? Justify your answer.
A young forest, a natural old forest, a shallow polluted lake, alpine meadow.
Answer:
Primary productivity can be defined as the rate at which primary producers (e.g. green plants) trap and store solar radiation in the form of biomass. This is measured in terms of weight (g^-2) and in terms of energy (kcal m^-2) per year in a given time. So, primary productivity varies from ecosystem to ecosystem and the ecosystem which possesses more producers will be more productive in terms of primary productivity.

So, young forests grow quicker than older mature forests and are more productive in terms of productivity.
The shallow polluted lake and alpine meadow will be less productive because of less number of producers and high amount of dead organic matter.

Question 8.
Why is the rate of assimilation of energy at the herbivore level called secondary productivity?
Answer:
The rate of assimilation of energy at herbivore (primary consumer) level is called secondary productivity because the biomass available to the organisms of this trophic level is a resultant of the primary productivity, which is formed by autotrophs (plants).

Question 9.
Why are oceans least productive?
Answer:
Oceans are least productive because

• there is insufficient radiation as sunlight decreases with the increasing depth of the ocean.
• oceans are nitrogen deficient which is an important nutrient for plants.
• conditions of high salinity in Ocean are not favourable for all plants.
• there is no substratum to support plants.

Question 10.
Write a note on decomposers.
Answer:
The microorganisms that breakdown the dead remains of plants, animals and organic matter into simpler inorganic substances are called decomposers.
These organisms are mainly aerobic and require oxygen-rich conditions to carry out their functioning. Their mode of nutrition is generally saprophytic as they ingest partially digested food material.

Question 11.
The rate of decomposition of detritus is affected by the abiotic factors like availability of oxygen, pH of the soil substratum, temperature, etc. Discuss.
Answer:
It is the process of breaking down of complex organic matter into inorganic substances like water, carbon dioxide and nutrients by decomposers. Detritus is the raw material for decomposition. It includes dead remains of plants (leaves, bark and flowers) and animals including faecal matter. Different steps involved in the process of decomposition are

1. Fragmentation It is the process of breakdown of detritus into smaller particles by detritivores (e.g. earthworm).
2. Leaching It is the process by which water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.
3. Catabolism It is the process of degradation of detritus into simple organic material by the action of bacterial and fungal enzymes and then they are further converted into simpler inorganic compounds.
4. Humification It is a process that leads to the accumulation of a dark coloured amorphous and colloidal substance called humus. It is highly resistant to microbial action and undergoes decomposition at a very slow rate. Being colloidal in nature, it serves as a reservoir of nutrients.
5. Mineralisation It is the process of degradation of humus by microbial action and release of inorganic nutrients.

Some are eaten by insects and other animals. Nutrients and energy enter food web.

Diagrammatic representation of decomposition cycle in a terrestrial ecosystem

Question 11.
Justify the following statement in terms of ecosystem dynamics.
‘Nature tends to increase the gross primary productivity, while man tends to increase the net primary productivity.’
Answer:
Gross primary productivity of an ecosystem is the rate of production of organic matter during photosynthesis. So, nature tends to increase gross primary productivity through supporting the large number of plants (producers) in an ecosystem.
Net primary productivity is the available biomass for the consumption by heterotrophs (human and animals).
Man tries to increase net primary productivity by cultivating food and other crops to fulfil their needs.

Question 12.
‘The energy flow in an ecosystem is unidirectional’. Justify the statement.
Answer:
Energy in an ecosystem flows from producers to primary consumers, then from primary consumers to secondary consumers and so on. There is never a backflow of energy, i.e. energy cannot come back to a trophic level it has already passed. Therefore, the energy flow is unidirectional in an ecosystem.

Question 13.
The diagram shows the flow of energy through an ecosystem.

Which arrows represent the smallest amount of energy transferred between organisms and the largest amount of energy lost to the ecosystem?
Answer:
The smallest amount of energy transferred is represented by arrow 2 and largest energy loss by arrow 3.

Question 14.
‘The energy flow in the ecosystem follows the second law of thermodynamics’. Explain.
Answer:
According to second law of thermodynamics, every activity involving energy transformation is accompanied by dissipation of energy as heat and increase in disorderliness, except in deep hydrothermal ecosystems.

This is because out of the total PAR only 2-10% is captured by photosynthetic organisms in synthesis of organic matter. Further, this energy is used during various metabolic processes for the formation of food and a very little is stored as biomass. This trapped energy as biomass is transferred to next trophic level according to Lindeman’s law. Only 10% of the stored energy is passed from one trophic level to successive trophic level.

Question 15.
Organisms at a higher trophic level have less energy available. Comment.
Answer:
Energy flow in the ecosystem follows the 10% energy flow law, proposed by Lindeman. According to this law, only 10% of the energy available at each trophic level, gets transferred to the next trophic level, the rest is lost in the environment as heat.

As we move to higher trophic levels, the energy available to organisms keeps on decreasing. Thus, the top . carnivore gains the least energy in a food chain.

Question 16.
The number of trophic levels in an ecosystem are limited. Comment.
Answer:
The number of trophic levels in an ecosystem are limited and are not more than 3-4. Because the amount of energy flow decreases with successive trophic level, as only 10% of energy is transferred from one trophic level . to the next trophic level.
So, rest of the energy is lost in the form of respiration and other vital activities to maintain life. If more trophic levels are present, the residual energy will be limited and will decrease to such an extent that it cannot further support any trophic level. So, the food chain is generally limited to 3-4 trophic levels only.

Question 17.
Write a short note on food chain.
Answer:
The transfer of energy from green plants through a sequence of organisms, in which each eats the one below it in the chain and is eaten by the one above is called a food chain. It is actually a feeding chain of organisms in an ecosystem.

Based on the relationship among the organisms and the source of their nutrition or food, organisms occupy a specific place in the food chain that is known as their trophic level. An assemblage of trophic levels within the ecosystem is known as trophic structure.
A single species may occupy multiple trophic levels in a food.
Example

• Grass → Grasshopper → Frog → Snake → Eagle.
• Grass → Goat → Man

Question 18.
Three food chains are shown below
(i) Grass → Deer → Tiger
(ii) Tree → Beetle → Bacteria
(iii) Flowering plant → Butterfly → Bird
They can be represented by the three pyramids of numbers P, Q and R below

Write the correct combination that correctly matches food chains and pyramids.
Answer:
P → 3, Q → 1, R → 2

Question 19
Define ecological pyramids and describe with examples, pyramids of number and biomass.
Or
Write a short note on ecological pyramids.
Answer:
Ecological pyramids are diagrammatic illustrations of connection between different trophic levels in terms of energy, biomass and number of organisms.
Pyramid of biomass can be both upright and inverted. This can be understood from the examples given below

1. The pyramid of biomass in a pond ecosystem is inverted. Because, the sum total of the weight of phytoplankton (producer) is far less than a few fishes feeding on them, at higher trophic levels.
2. Pyramid of biomass in a forest ecosystem is upright because producers are more in biomass than primary consumers. Primary consumers are more than secondary consumers and secondary consumers are more than tertiary consumers (top).

Pyramid of energy is never inverted (i.e. it is always upright). Because, when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step.
Each bar in the energy pyramid indicates the amount of energy present at each trophic level in a given time.

Question 20.
Write a note on pyramid of energy.
Answer:
Pyramid of Energy
It represents the total amount of energy utilised by different trophic level organisms in unit area over a period of time.

An ideal pyramid of energy with primary producers storing only 196 of solar energy as NPP

Its unit is kj/ha/yr. Pyramid of energy is always upright, i. e. it can never be inverted, because when energy is transferred from a particular trophic level to the next trophic level, some energy is always lost as heat at each step. It is in accordance with the first law of thermodynamics which states that energy is always conserved, it is neither created nor destroyed.

Question 21.
Fill in the missing stages in the given primary hydrarch succession.
Phytoplankton → A → B → C → Submerged free-floating → D → Forest plant stage
Answer:
A – Reed-swamp stage
B – Submerged plant stage
C – Marsh-meadow stage
D – Shrub stage.

Question 22.
Mention the role of pioneer species in primary succession on rocks.
Answer:
Lichens are pioneer species in primary succession on rocks. They secrete organic acids, which wither the rock and help in soil formation. Lichens by forming soil pave way for the next community, i.e. bryophytes.

Question 23.
Write the notes on the following
(i) Define pioneer species.
(ii) Among bryophytes, lichens and fern, which one is a pioneer species in a xeric succession and why?
Answer:
(i) The species that invade a bare area are called pioneer species.
(ii) In a xeric succession, the pioneer species are usually lichens then bryophytes, which are succeeded by ferns and some other bigger plants.

Lichen produces lichen acid and carbonic acid which corrode rock surface and release minerals required for growth. The corroded rock accumulates soil particle by wind and provides substrate for bryophytes and ferns.

Question 24.
State the function of a reservoir in a nutrient cycle. Explain the simplified model of carbon cycle in nature.
Answer:
The function of reservoir is to meet the deficit which occurs due to imbalance in the rate of influx and efflux.

Question 25.
Why are nutrient cycles in nature called biogeochemical cycles?
Answer:
Nutrient cycles are called biogeochemical cycles because ions/molecules of a nutrient are transferred from the environment (rocks, air and water) to organisms (life) and then brought back to the environment in a cyclic pathway.
The literal meaning of biogeochemical is bio – living organism and geo – rocks, air and water.

Question 26.
Outline the salient features of carbon cycle in an ecosystem.
Answer:
Carbon constitutes 45% of dry weight of organisms and it is next only to water. About 71% carbon is found dissolved in oceans. This oceanic reservoir regulates the amount of carbon dioxide (CO₂) in the atmosphere. The fossil fuels also represent a reservoir of carbon.Therefore, carbon cycling occurs through atmosphere, ocean and through living and dead organisms.

Approximately, 4 × 10¹³ kg of carbon is fixed in the biosphere through photosynthesis annually. Carbon-fixation or carbon assimilation refers to the conversion process of inorganic carbon (carbon dioxide) into organic compound. CO₂ is returned to the atmosphere via respiratory activities of producers and consumers. Decomposers also contribute substantially to CO₂ pool by their processing of waste materials and dead organic matter of land or oceans.

Various activites like burning of wood, forest fire and cqmbustion of organic matter, fossil fuels and volcanic eruption contributes to additional sources of CO₂ release into the atmosphere.
Human activities have significantly influenced the carbon cycle, e.g. rapid deforestation and burning of fossil fuel for energy and transport have significantly increased the rate of release of carbon dioxide into the atmosphere.

Question 27.
Complete the following model of carbon cycle by filling A, B, C, D, E and F.

Answer:
A – Respiration,
B – Photosynthesis,
C – Respiration,
D – Combustion of fossil fuels
E – Aquatic food chain and
E – Coal and oil.

Question 28.
Write important features of a sedimentary cycle in an ecosystem.
Answer:
Phosphorus cycle is an example of sedimentary nutrient cycle, since, it moves from land to the sediments at the bottom of the seas, then back to land again. The natural reservoir of phosphorus is earth’s crust. Rocks contain phosphorus in the form of phosphates.

By weathering and soil erosion, phosphates enter streams, rivers and then to oceans. With great movements of the tectonic plates, sea floor is uplifted and phosphates become exposed to the drained land surfaces. From here, weathering for a long period of time releases phosphates from rocks. Minute amount of these phosphates dissolve in soil and are absorbed by the roots of the plants. Herbivores and other animals obtain this element from the plants.

Question 29.
Describe the advantages for keeping the ecosystems healthy.
Or
Write a short note on ecosystem services.
Answer:
The various benefits that humans obtain from the ecosystem are collectively called ecosystem services.
The advantages of keeping an ecosystem healthy can be grouped into following types

Healthy ecosystems are the base for a wide range of economic, environmental and aesthetic goods and services. Ecosystem services are the products of ecosystem processes, e.g. healthy forest ecosystem purifies air and water, mitigates droughts and floods, cycles nutrients, generates fertile soils, provides wildlife habitat, maintains biodiversity, pollinates crops, provides storage site for carbon and also provides aesthetic, cultural and spiritual values.

Although it is difficult to find out the monitory value of all these services, still it is reasonable to think that biodiversity should carry a hefty price tag.

Robert Constanza and his colleagues recently have tried to put price tag on the nature’s life-support services. Researchers have put a price tag of US $ 33 trillion a year on these fundamental ecosystem services, which we utilise for free. This is almost twice the value of global Gross National Product (GNP), which is of US $ 18 trillion. Out of the total cost of various ecosystem services, soil formation accounts for 50%.

Contribution of other services like recreation and nutrient cycling are less than 10% each. The cost of climate regulation and habitat for wildlife are about 6% each.

Differentiate between the following (for complete chapter)

Question 1.
Standing crop and Standing state.
Answer:
Differences between standing crop and standing state are as follows

Standing crop	Standing state
It is amount of biomass present in an ecosystem.	It is amount of inorganic nutrients found in an ecosystem.
It represents the entire living matter.	It represents a part of non-living matter.
There is no circulation of this matter.	It circulates between living and non-living components of the ecosystem.
Continuous synthesis and consumption of biomass goes on.	It is being regularly depleted and replenished by the living matter.

Question 2.
Primary productivity and Secondary productivity.
Answer:
Differences between primary productivity and secondary productivity are as follows

Primary productivity	Secondary productivity
It is the rate of synthesis of organic matter by producers.	It is the rate of synthesis of organic matter by consumers.
It is comparatively quite high.	It is small and decreases with rise of trophic level.
It is due to synthesis of fresh organic matter from inorganic raw materials.	It is due to synthesis of organic matter from organic matter.

Question 3.
Detritivores and Decomposers.
Answer:
Differences between detritivores and decomposers are as follows

Detritivores	Decomposers
These are animals which feed on detritus.	These are microorganisms which obtain nourishment from organic remains.
These ingest the organic matter.	These decompose the organic matter by secreting digestive enzymes over it.
Ecologically, they cause pulverisation or fragmentation of detritus, e.g. earthworm, carrion beetle.	Ecologically, they cause humification and mineralisation of organic matter, e.g. Pseudomonas, slime moulds.

Question 4.
Production and Decomposition.
Answer:
Differences between production and decomposition are as follows

Production	Decomposition
It is the process of synthesis organic compounds/biomass from inorganic matter using sunlight by producers (e.g. plants).	It is the process of of breaking down of a substance/waste biomass into its constituent parts by decomposers, e.g. bacteria, fungi.
It traps the energy.	It releases the energy.
It builds up biomass from inorganic nutrients.	It releases inorganic nutrients from the biomass.

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 14 Organisms and Environment Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 14 Organisms and Environment

Organisms and Environment Class 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
Plants and animals living in a particular area constitute
(a) flora and fauna
(b) community
(c) ecosystem
(d) ecology
Ans.
(b) community

Question 2.
Biome is defined as
(a) sum of ecosystem in a geographical area
(b) sum of ecosystem of the whole earth
(c) biotic potential of a population
(d) biotic component of a ecosystem
Ans.
(a) sum of ecosystem in a geographical area

Question 3.
The adaptation of aquatic plants which roots are poorly developed is seen in
(a) Eichhornia
(b) Nymphaea
(c) Dunaliella
(d) Vallisneria
Ans.
(d) Vallisneria

Question 4.
Plenty of aerenchyma are found in
(a) hydrophytes
(b) mesophytes
(c) xerophytes
(d) halophytes
Ans.
(a) hydrophytes

Question 5.
The plant that does not belong to the ecological group, represented by the other plants is
(a) Pistia
(b) Casuarina
(c) Jussiaea
(d) Hydrilla
Ans.
(b) Casuarina

Question 6.
Sunken stomata are seen in
(a) hydrophytes
(b) xerophytes
(c) parasites
(d) symbionts
Ans.
(b) xerophytes

Question 1.
The organisms and their environment in a particular area
(a) bioregion
(b) biosphere
(c) ecosystem
(d) biome
Answer:
(c) ecosystem

Question 2.
Community is a group of independent and interacting population of
(a) different species
(b) same species
(c) same species in a specific area
(d) different species in a specific area
Answer:

Question 3.
Group of two or more than two plant species is called as
(a) plant community
(b) animal ecosystem
(c) plant ecosystem
(d) ecological niche
Answer:
(a) plant community

Question 4.
Which of the following is an animal of benthic zone?
(a) Frog
(b) Chemosynthetic bacteria
(c) Rat
(d) Human being
Answer:
(b) Chemosynthetic bacteria

Question 5.
Example of submerged hydrophyte is
(a) Hydrilla
(b) Lemna
(c) Nelumbium
(d) Eichhornia
Answer:
(a) Hydrilla

Question 6.
An association of two organism living together and benefitting each other is called ……….
(a) mutualism
(b) saprophytism
(c) parasitism
(d) commensalism
Answer:
(a) mutualism

Question 7.
A high density of tiger population is an area can result is
(a) predation
(b) interspecific competition
(c) intraspecific competition
(d) protocooperation
Answer:
(c) intraspecific competition

Question 8.
Which of the following shows detrimental effects on species
(a) mutualism
(b) predation
(c) parasitism
(d) competition
Answer:
(d) competition

Question 9.
Plasmodium is an example of
(a) predator
(b) endoparasite
(c) prey
(d) ectoparasite
Answer:
(b) ectoparasite

Question 10.
Monarch butterfly is not eaten by predators because of
(a) rough skin
(b) bitter taste
(c) foul smell
(d) colouration
Answer:
(b) bitter taste

Question 11.
The association of animals where both partners are benefitted is
(a) commensalism
(b) amensalism
(c) mutualism
(d) parasitism
Answer:
(c) mutualism

Question 12.
There are two optimal ways of exploitation one way is parasitism. Which is the other one?
(a) Antibiosis
(b) Competition
(c) Predation
(d) Commensatism
Answer:
(c) Predation

Question 13.
The most important factor which determined the increase in human population in India during 20th century is
(a) natality
(b) mortality
(c) immigration
(d) emigration
Answer:
(c) immigration

Question 14.
Population density is represented by
(a) N/S
(b) N/t
(c) t/S
(d) DNn/Dt
Answer:
(d) DNn/Dt

Question 15.
Natality increases the
(a) population density
(b) population size
(c) number of organisms in the population
(d) All of the above
Answer:
(d) All of the above

Fill in the blanks

Question 1.
Some xerophytes have multiple epidermis like …………. .
Answer:
Nerium

Question 2.
Leaves are large, broad and thin in …………. plants.
Answer:
mesophytic

Question 3.
Fish, amphibians and reptiles are ……………. .
Answer:
stenothermal animals

Question 4.
Root caps are present in ………….. .
Answer:
mesophytes

Question 5.
………. is the mechanism evolved by competing species for co-existence.
Answer:
Resource partitioning

Question 6.
Fig and wasp show ralationship.
Answer:
mutualistic

Correct the statements, if required by changing the underlined words

Question 1.
Plants which grow in bright light are called sciophytes.
Answer:
heliophytes

Question 2.
The organism which can tolerate a wide range of temperature are called stenothermal organisms.
Answer:
eurythermai

Question 3.
Plants growing in moist habitat are known as xerophytes.
Answer:
mesophytes

Question 4.
Plants growing in dry land are called mesophytes.
Answer:
xerophytes

Question 5.
Lichens represent an intimate mutualistic relationship between fungus and algae.
Answer:
It is correct

Question 6.
Mediterranean orchid ophrys employs sexual compatibility to get pollinated by bee.
Answer:
sexual deceit

Express in one or two words

Question 1.
The type of habitat in which plants are adapted to live in water scarcity.
Answer:
Xeric habitat.

Question 2.
The type of organisms who change their osmotic concentration according to the environment.
Answer:
Osmoconformers.

Question 3.
The factors which are related to soil in a habitat.
Answer:
Edaphic factors.

Question 4.
Plants growing or adapted to live in the shade.
Answer:
Sciophytes

Question 5.
Plants that grow best in direct sunlight.
Answer:
Heliophytes

Question 6.
The mechanism in which one animal kills other and eat it.
Answer:
Predation

Question 7.
The mechanism in which one species depend on the other for food and shelter.
Answer:
Parasitism

Short Answer Type Questions

Question 1.
Write different features of mesophytes.
Answer:
These are plants which grow in moist habitats and need well-aerated soils. These show the following characteristics

1. Root system is well-developed. They are branched, with root caps and root hairs.
2. Stems are aerial and freely branched.
3. Leaves are large, broad and thin.
4. Cuticle in all aerial parts is moderately developed.
5. The stomata are dorsiventral in dicotyledons and isobilateral position in monocot leaves.
6. The photosynthetic are in leaf, i.e., mesophyll tissue in differentiated into palisade, parenchyma and spongy parenchyma.
7. Water and food conductive tissue (vascular tissue) and mechanical tissue (collenchyma and sclerenchyma are well-developed.)

Question 2.
Write a note on hydrophytes.
Answer:
Hydrophytes
The plants growing in abundance of water or wet place are called hydrophytes. These plants may be partially or wholly submerged in water.
The aquatic habit at provides the following to the plant to grow

1. Availabity of nutrients in the water.
2. Plant growth matrix.
3. Approximate constant temperature (with least variation).
4. Availability of light.
5. Movement of water (waves strong or weak).

Based on the relation of plants to water and air.

Question 3.
Write short note on hydrophytic adaptations in roots of plants.
Answer:
Adaptations in hydrophytes can be discussed under three headings, i.e. morphological, anatomical and physiological.
1. Morphological Adaptations
Hydrophytes show various kinds of structural adaptations in their roots, stems and leaves.

• Roots may be entirely absent, e.g. Wolffia, Salvinia or poorly developed, e.g. Hydrilla.
• Roots are well-developed with distinct root caps, e.g. Ranunculus (emergent hydrophytes), aerenchyma present.
• In Eichhornia root caps are replaced by root pockets.
• Some plants, i.e. Jussiaea have two types of roots, one is normal type and other is spongy and negatively geotrophic.

Question 4.
What are free-floating and rooted hydrophytes?
Answer:
Free-floating hydrophytes These plants are absolutely float freely on the water surface and are not linked to the soil or substratum, e.g. Duck weed (Lemna and Wolffia), water hyacinth (Eichhomia crassipes), water ferns (Azolla and Salvinia).

Question 5.
What is habitat? Name some factors which define habitat of an organism.
Answer:
Habitat is a natural abode or a locality where a plant or animal grows or in other words, where a species lives.
The factors which define habitat can be climatic temperature, humidity, edaphic, i.e. related to soil, topographic or physical.

Question 6.
List various adaptations shown by epidermis in xerophytic plants.
Answer:
Physiologically dry habitats have plants of water, but the water is not available to the plant.
Based on their adaptation to water scarcity or drought conditions, xerophytes are of three types

1. Drought resistant plants are such that they can survive in extreme conditions, drought enduring plants can tolerate drought though they may hot have adaptation.
2. Drought enduring plants these do not have distinct adaptation.
3. Drought escaping plants these are short lived plants, complete the life cycle before the arrival of dry condition, e.g. Artemisia, Astragalus.

Question 7.
Does light factor affect the distribution of organisms? Write a brief note giving suitable examples of plants.
Answer:
Plants require sunlight for photosynthesis. Therefore, light is an important factor that affects the distribution of plants, e.g.

1. Many species of small plants (herbs and shrubs) growing in forests are adapted to photosynthesis optimally under very low light conditions so, they are seen distributed in shady areas under tall, canopied trees.
2. Many plants in the shade will grow vertically to gain access to light. These plants will appear to have smaller leafs than others of the same species of the , same age found in conditions with better sunlight.
3. Large sized trees will be present in areas that get abundant sunlight.

Question 8.
List any four characteristics that are employed in human population census.
Answer:
A population has the following characteristics that are employed in human population census

• Natality and mortality
• Sex-ratio
• Population density
• Age distribution

Question 9.
Describe the mutual relationship between the fig tree and wasp and comment on the phenomenon that operates in their relationship.
Answer:
The relationship between fig tree and wasp shows mutualism. The wasp while searching for sites to lay its eggs, pollinates the fig’s inflorescence.
On the other hand, the fig not only provides shelter (fruit) for oviposition, but also allows wasp’s larva to feed on its seeds.

Question 10.
What is mutualism? Mention any two examples where the organisms involved are commercially (2018) exploited in agriculture.
Answer:
It is an interaction that confers benefits to both the interacting species. Some examples of mutualism are

1. Lichens represent an intimate mutualistic relationship between a fungus (mycobiont) and photosynthesising algae (phycobiont) or cyanobacteria. Here, the fungus helps in the absorption of nutrients and provides protection, while algae prepares the food.
2. Mycorrhiza show dose mutual association between fungi and the roots of higher plants. Fungi help the plant in absorption of nutrients, while the plant provides food for the fungus, e.g. many members of genus -Glomus.
3. Plants need help from animals for pollination and dispersal of seeds. In return, plants provide nectar, pollens and fruits to them

Question 11.
Name important defence mechanisms in plants against herbivory.
Answer:
The herbivores are predators of plants and nearly 25% insects are phytophagous (feeding on plants). So, plants show morphological as well as chemical defence against herbivores such as

1. Thorns of rose and Acacia as well as cactus.
2. Certain plants produce chemicals, such as Opium, quinine, caffeine, nicotine, to protect them against being grazed by the animals.
3. Calotropis produces highly poisonous cardiac glycosides. So, the cattle and goats do not eat this plant.

Question 12.
What is predation? Explain with the help of suitable examples why is it required in a community with rich biodiversity.
Answer:
Predation is an interaction where one organisms (predator) kills and eats the other weaker organisms called prey.
Predation is a natural way of transferring the energy fixed by plants, to higher trophic levels.
Examples-snake eating a frog, tiger killing and eating a deer. Predators keep prey population under control which otherwise could achieve very high population densities and cause instability in ecosystem.
They also help in maintaining a species diversity in a community by reducing. The intensity of competition among competing prey species.

Question 13.
Name the interaction in each of the following:
(i) Cuckoo lays her eggs in the crow’s nest.
(ii) Orchid grows on a mango tree.
(iii) Ticks live on the skin of dogs.
Answer:
(i) Brood parasitism.
(ii) Commensalism, orchid is an epiphyte.
(iii) Parasitism, ticks are ectoparasites.

Question 14.
Explain the S-shaped pattern of population growth. How is J-shaped pattern different from it and why?
Answer:
S-shaped pattern of population growth form shows an initial gradual increase, followed by an exponential increase and then a gradual decline to a near constant level. It is different from J-shaped curve because J-shaped pattern shows exponential population growth and its abrupt crash after attaining the peak value. A-When resources are not limiting the growth, plot is exponential. B-When resources are limiting the growth, plot is logistic, K is the carrying capacity.

Question 15.
Explain diagrammatically the age structure of expanding, stable and declining population.
Answer:
The pyramids can be of three difference types as follows
1. Expanding (Triangular) This is a type of a growing population representation is like a triangle.
The population carries a high proportion of pre-reproductive individuals followed by reproductive individuals and post-reproductive individuals. Because of the very large number of pre-reproductive individuals, more and more of them enter reproductive phases and rapidily increases the size of the population.

2. Stable (Bell-shaped) This type of pyramid will represent a stationary or stable population having an equal number of young and middle aged class of individiuals.

3. Declining (Urn-shaped) This group has a small number of pre-reproductive individuals followed by a large number of reproductive individuals. As, there is less number of individuals in pre-reproductive groups.

Differentiate between the following (for complete chapter)

Question 1.
Population and Community.
Answer:
Differences between population and community are as follows

Population	Community
It is a grouping of individuals of a single species found in an area.	It is grouping of individuals of different species found in an area.
All the individuals of a population are morphologically and behaviourly similar.	Different members of a community are morphologically and behaviourly dissimilar.
Individuals of a population interbreed freely.	Interbreeding is absent amongst different members of a community.

Question 2.
Mesophytes and Hydrophytes.
Answer:
Differences between mesophytes and hydrophytes are as follows

Mesophytes	Hydrophytes
The plants grown on terrestrial habitate (land).	These are found in aquatic habitate (water).
The root septum is very cell developed in there plants.	Root system is not very well-developed or absent.
Leaves are broad, large and thin, mucilage covering is absent.	Leaves are, thin ribbon-shaped and covered with mucilage.

Question 3.
Mutualism and Commensalism.
Differences between mutualism and commensalism are as follows

Mutualism	Commensalism
In this two species are involved, both derive benefit from each other.	Two species involved but only one ge{ benefit other remain unharmed.
Example-see-anemone and hermit-crab.	Example-Sucker fish and shark.

Question 4.
Parasitism and Predation.
Answer:
Differences between parasitism and predation are as follows

Parasitism	Predation
It is host specific.	Predators have choice of prey.
Parasites are smaller is size.	Predators are large in size.
These have high reproductive potential.	These have low reproductive potential.

Question 5.
Ectoparasites and Endoparasites.
Answer:
Differences between ectoparasites and endoparasites are as follows

Ectoparasites	Endoparasites
Ectoparasites live on the surface of the host.	Endoparasites live in the body of the host.
They can be temporary, intermittent or permanent.	They are generally permanent parasites.
They can be hemiparasites or holoparasites.	They are usually holoparasites.
Respiration is aerobic.	Respiration is ofter anaerobic.
Specialisation has lead to loss of fewer strutures, e.g. wings in fleas, bedbugs and lice.	Specialisation has led the loss of several structures, e.g, digestive organs in Taenia.

Question 6.
Immigration and Emigration.
Answer:
Differences between immigration and emigration are as follows

Immigration	Emigration
It is permanent inward movement of some individuals into a local population.	It is a permanent outward movement of some individuals from a local population.
Size of gene pool and local population in increases.	Size of gene pool and local population decreases.
It is caused by availability of better living conditions.	It is caused by occurrence of deficiencies and calamities.

Question 7.
Camouflage and Mimicry.
Answer:
Differences between camouflage and mimicry are as follows

Camouflage	Mimicry
It is the ability of animals to blend with the background.	It is resemblance of on species of animals with another species.
Camouflage allows the animals to remain unnoticec from a distance.	Mimicry hides the true 1 identity of the animal species.
It is advantageous to both prey as well as predator.	It is advantageous to mimics against predation.

Question 8.
Intraspecific competition and Interspecific competition.
Answer:
Differences between intraspecific competition and interspecific competition are as follows

Intraspecific competition	Interspecific competition
It is competition among individuals of the same species.	The competition is amongst the members of different species.
The competition is for all the requirements.	The competition is for one or a few requirements.
The competing individuals have similar type of adaptation.	The competing individuals have different types of adaptations.
It is more severe due to similar needs and adaptations.	It is less severe as the similar needs are a few and the adaptations are different.

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 13 Applications of Biotechnology Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 13 Applications of Biotechnology

Applications of Biotechnology Class 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
A biotech company that released first ever genetically manipulated flower into the market is
(a) Cryobank
(b) Eli Lilly
(c) Florigene
(d) Genentech
Ans.
(c) Florigene

Question 2.
When an abnormal gene is replaced by normal gene, what do you call it? (2023)
(a) Gene mutation
(b) Gene donning
(c) Gene therapy
(d) Gene ligation
Ans.
(c) Gene therapy

Question 3.
Cry II Ab and Cry I Ab produce toxins that control
(a) cotton bollworms and corn borer, respectively
(b) corn borer and cotton bollworms, respectively
(c) tobacco budworms and nematodes, respectively
(d) nematodes and tobacco budworms, respectively
Ans.
(a) cotton bollworms and corn borer, respectively

Question 4.
First genetically modified plant commercially released in India is
(a) golden rice
(b) slow ripening tomatoes
(c) Bt-bringal
(d) Bt-cotton
Ans.
(d) Bt-cotton

Question 5.
Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because
(a) bacteria are resistant to the toxin
(b) toxin is immature
(c) toxin is inactive
(d) bacteria enclose toxin in a special sac
Answer:
(c) toxin is inactive

Question 6.
Basic principle of developing transgenic animals is to introduce the gene of interest into the nucleus of
(a) somatic cell
(b) vegetative cell
(c) germ cell
(d) body cell
Answer:
(c) germ cell

Question 7.
Which among the following pharmaceutical products is harvested by using transgenic animals as bioreactors?
(a) Urokinase
(b) Insulin
(c) Lactoferrin
(d) All of these
Answer:
(d) All of these

Question 8.
The superbug can be used in
(a) oil spills
(b) water pollution
(c) eutrophication
(d) air pollution
Answer:
(a) oil spills

Question 9.
Biopatents are usually awarded for the discovery of
(a) new cell lines
(b) new DNA sequences
(c) GM strains
(d) All of these
Answer:
(d) All of these

Question 10.
Exploitation of patent biological resources of a country by another country is known as?
(a) biopatent
(b) biopiracy
(c) biowar
(d) All of these
Answer:
(b) biopiracy

Question 11.
Patents are given for
(a) discoveries
(b) inventions
(c) biopiracy
(d) gene therapy
Answer:
(b) inventions

Questions 12.
Which one of the following known as ‘Superbug’?
(a) Pseudomonas putida
(b) E. coli
(c) Aspergillus niger
(d) Acetobacter aceti
Answer:
(a) Pseudomonas putida

Questions 13.
US Patent on turmeric was challanged by
(a) CSIR
(b) EPO
(c) FSSAI
(d) FDI
Answer:
(a) CSIR

Questions 14.
Biopiracy is
(a) the use of biological patent
(b) thefts of plants and animals
(c) the use of bioresources of a country without proper authorisation
(d) stealing of biological resources
Answer:
(c) the use of bioresources of a country without proper authorisation

Correct the statements, if required, by changing the underlined words

Question 1.
An amorphous mass of parenchyma cells developed by tissue culture is called embryo.
Answer:
Callus

Question 2.
Petunia is ice minus strain which when sprayed on crops prevents frost formation.
Answer:
Pseudomonas

Question 3.
The natural source of vitamin-E is α-tocopherol.
Answer:
γ-tocopherol

Question 4.
The first GMO was created by Watson.
Answer:
Herbert Boyer and Stanley Cohen.

Question 5.
Soil bacterium Nitrosomonas syringae promotes ice nucleation in plants.
Answer:
Pseudomonas

Question 6.
The C-peptide is added during the maturation of pro-insulin to insulin.
Answer:
deleted

Question 7.
ADA treatment uses monocytes.
Answer:
lymphocytes

Question 8.
Antitrypsin is an agent that dissolves blood clot.
Answer:
Tissue Plasminogen Activator (TPA).

Question 9.
The first transgenic cow was Lilly.
Answer:
Rosie

Question 10.
A Pacific transgenic whale was generated by a growth hormone transgene.
Answer:
salmon

Question 11.
Transgenic mouse is smaller than the normal mouse.
Answer:
larger

Question 12.
Human protein α-2-trypin is used to treat emphysema.
Answer:
α-1-antitrypsin

Express in one or two word(s)

Question 1.
Define callus.
Answer:
It is undifferentiated mass of totipotent cells in the culture media.

Question 2.
Name one plant used to create novel transgenic plants.
Answer:
Petunia

Question 3.
Name the drugs isolated from Catharanthus roseus for cancer treatment.
Answer:
Vincristine and vinblastine.

Question 4.
Which microorganism is used as cloning host cell to produce humulin?
Answer:
E. coli

Question 5.
State the number of polypeptides found in mature human insulin.
Answer:
Two

Question 6.
What do you mean by the term transgene?
Answer:
oreign gene that is incorporated in an orgainsm to bring about desirable changes.

Question 7.
Where the LDL receptors are present?
Answer:
On the surface of hepatocytes

Question 8.
What is the name of the scientist who coined a sheep named Dolly?
Answer:
Keith Campbel and Ian Wilmut.

Question 9.
Name the institute that came up with a cloned sheep, named Dolly.
Answer:
Ian Wilmut of Roslin Institute in Scottland.

Question 10.
Which department of the Goverment of India is the nodal centre for Indian biosafety network?
Answer:
Department of biotechnology.

Question 11.
Which bacterium species is involved in Diamond vs Chakraborty case?
Answer:
Pseudomonas

Question 12.
What are transgenic animals?
Answer:
Genetically modified organism

Question 13.
Name the first transgenic cow that produced human protein enriched milk.
Answer:
Rosie

Question 14.
Name a transgenic animal being used in testing the safety of polio vaccine.
Answer:
Mouse

Question 15.
Mention the name of two common diseases that can be treated by medicines that contain biological products of transgenic animals.
Answer:
Cystic fibrosis and rheumatoid arthritis

Question 16.
What is patent?
Answer:
It is an open latter, a set of legal right, privilege and authority granted by a sovereign state to a person or institution for an invention for a limited period of time.

Fill in the blanks

Question 1.
…………… is a mammalian protein that have been successfully expressed in plants.
Answer:
Enkephalin.

Question 2.
Genetically engineered rice rich in vitamin-A is known as ……………… .
Answer:
golden rice

Question 3.
The recombinant human insulin is known as …………. .
Answer:
humulin

Question 4.
The full form of ELISA is ………… .
Answer:
Enzyme Linked Immunosorbant Assay.

Question 5.
Primarily, insulin is synthesised as ……………. .
Answer:
single polypeptide.

Question 6.
SCID is caused due to failure of synthesis of enzyme ………….. .
Answer:
adenosine deaminase.

Question 7.
…………. is the precursor of vitamin-A.
Answer:
ß-carotene

Question 8.
………… infects the roots of tobacco plants.
Answer:
Agrobacterium

Question 9.
The transgenic mouse is called as …………….. .
Answer:
Super mouse

Question 10.
…………. is a transgenic sheep.
Answer
Dolly

Question 11.
…………. is an infant nutrition formula that have been harvested using transgenic animals as bioreactors.
Answer:
Lactoferrin.

Question 12.
In 1990 ……….. the transgenic ewe was born in Scottland.
Answer:
Tracy

Question 13.
Full from of TPA is ……………. .
Answer:
Tissue Plasminogen Activator.

Question 14.
Neem patent case was first awarded in favour of ……………. .
Answer:
USA.

Short Answer Type Questions

Question 1.
Find out from the internet what is golden rice.
Answer:
Golden rice is a genetically modified rice with high levels of ß-carotene and other carotenoids. This rice is modified in order to enhance the quantity of vitamin-A in it. It is called golden due to the gold-like colour it gets from ß-carotene.

Question 2.
Can a disease be detected before its symptoms appear? Explain the principle involved.
Answer:
When the symptoms of the disease are not visible and the pathogen concentration is very low, then detection by conventional diagnostic tests is very difficult. However, detection at the above stated stage is made possible by molecular diagnostic techniques like the amplification of their nucleic acid by Polymerase Chain Reaction (PCR). The principle involved here is that a single DNA molecule can be copied endlessly in a test tube, using primers, DNA polymerase enzyme and free nucleotides and appropriate conditions.

Question 3.
How is DNA recombinant technology helpful in detecting the presence of mutated genes in the cancer patients?
Answer:
Molecular diagnosis in DNA recombinant technology uses a single-stranded DNA or RNA tagged with a radioactive molecules. It is allowed to hybridise to its complementary DNA in a clone of cells followed by detection using autoradiography. The clone having the mutated gene will not appear on the photographic film, because the probe used will not be complementary to the mutated gene. In this way, presence of mutated genes can be detected.

Question 4.
Why is the functional insulin produced, considered better than the ones used earlier by diabetic patients?
Answer:
Insulin prepared by rDNA technology does not produce sensitive allergic reactions and complications to the foreign protein which occurred in the case of earlier extracted insulin from the pancreas of slaughtered cattle or pigs. Thus, it is considered better than the earlier used insulin.

Question 5.
How is a mature, functional insulin hormone different from its pro-hormone form?
Answer:
Mature functional insulin is obtained by the processing of pro-hormone which contains extra peptide called C-peptide. This C-peptide is removed during the maturation of pro-insulin to insulin.

Question 6.
Refer to the diagram given below and answer the questions that follows

(i) The diagram shown above is insulin or proinsulin? Justify.
(ii) How is mature insulin synthesised?
Answer:
(i) The diagram is proinsulin as it contains C-peptide.
(ii) Mature insulin is synthesised by the removal of extra stretch called C-peptide.

Question 7.
How did an American Company, Eli Lilly use the knowledge of rDNA technology to produce human insulin?
Or
How did Eli Lilly synthesise the human insulin? Mention one difference between this insulin and the one produced by the human pancreas.
Or
What is humulin?
Answer:
The production cost was high due to its complex extraction and purification processes. Additionally, the purified insulin was contaminated by many pathogenic viruses. These problems have been overcome by the use of recombinant DNA technology. Insulin that is produced by recombinant DNA technology is known as recombinant human insulin.

Question 8.
Recombinant DNA technology is of great
importance in the field of medicine. With the help of a flow chart, show how this technology has been used in preparing genetically engineered human insulins.
Answer:
Insulin production by using recombinant DNA technology is shown in flow chart below

Question 9.
What is gene therapy? Name the first clinical case in which it was used.
Or
What is gene therapy? Illustrate using the example of Adenosine Deaminase (ADA) deficiency.
Answer:
It is a method of treatment which allows correction of a biochemical (like phenylketonuria) or a genetic defect*that has been diagnosed in a child or embryo. The defective mutant alleles of the gene are replaced by the normal gene insertion to take over the function of and compensate for the non-functional gene. Gene therapy is widely used to treat

• Biochemical disorder, e.g. alkaptonuria, phenylketonuria, albinism, etc.
• Chromosomal and gene disorders, e.g. Down’s syndrome, Turner’s, syndrome, Klinefelter’s syndrome, fragile X-syndrome, cri-du chat, Huntington’s disease, Tay-Sach’s syndrome, etc.

Question 10.
Write a note on genetically modified organism.
Answer:
The plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO).
These are also called transgenic organisms, as they contain and express one or more foreign genes called transgenes. Herbert Boyer and Stanley Cohen developed the first GMO in 1973.

They transferred the Kanamycin antibiotic resistance gene of a bacterium into the another Kanamycin sensitive bacterium.
The genes which are being transferred are called transgenes.
The recepient bacterium later acquired Kanamycin resistance. Following many such discoveries, GMOs were developed. Novel plants and animals were created by genetic manipulation for human welfare.

Question 11.
Write a short note on transgenic plants.
Answer:
Herbicide resistant plants Herbicide resistant transgenic plants are generated by transferring bacterial herbicide resistant genes into plant cells grown in culture. Glyphosate is the most widely used broad-spectrum herbicide world over.

A glyphosate resistant gene from Petunia plant is transferred into isolated plant cell§ in culture and glyphosate resistant plants are generated.

Question 12.
Write a short note with 2-3 important points on Bacillus thuringiensis.
Or
Why do the toxic insecticide proteins secreted by Bacillus thuringiensis kill insects?
Answer:
Bacillus thuringiensis (Bt) It is a soil-borne, Gram-positive bacterium. It is used to create transgenic plants having resistance to different pests. The genes having insecticidal properties in the bacterium are isolated and incorporated into plants by using advanced biotechnological methods to create Bt plants. During sporulation, many Bt strains produce crystal proteins (proteinaceous inclusions) called S-endotoxins, that have insecticidal action.

When consumed by insect, these toxins bind to the surface of midgut epithelial cells and create pores that cause cell swelling and lysis, leading to the death of an insect, e.g. 5r-cotton, fir-tomato, soybean, coffee, etc.

Question 13.
Why does Bt toxin cannot kill the bacterium that produces it, but kills the insect that ingests it?
Answer:
Bt toxin is produced by a soil bacterium called Bacillus thuringiensis. This toxin does not kill the bacterium which produces it, because in them, it is present in an inactive and crystalline form. It becomes active and toxic only when it is consumed by insects such as lepidopterans, etc. due to the alkaline pH of the gut.

Question 14.
Bt cotton is resistant to pests, such as lepidopterans, dipterans and coleopterans. Is Bt cotton resistant to other pests as well?
Answer:
Bt cotton is made resistant only to certain specific taxa of pests. It is quite likely that in future some other pests may infest this Bt cotton. It is similar to immunisation against smallpox which does not provide immunity against other pathogens like those that cause cholera, typhoid, etc.

Question 15.
Why certain cotton plants are called Bt cotton?
Answer:
Cotton plants are called Bt cotton because they bear specific Bt toxin genes which were isolated from Bacillus thuringiensis and incorporated into certain cotton plants. This helps the host plants in developing resistance against and various pests like bollworms, etc.

Question 16.
Differentiate the terms ‘Cry’ and ‘cry’.
Answer:
‘Cry’ refers to protein symbol and its first letter is always capital. It is written in Roman letters, ‘cry’ refers to the gene which is usually written in small letters and is invariably in italics.

Question 17.
What are Cry proteins? Name an organism that produces it. How has man exploited this protein to his benefit?
Or
Name the source and type of cry genes used for incorporation into crops by biotechnologists. Explain, how have these genes brought beneficial changes in the genetically modified crops.
Answer:
The proteins encoded by the gene named cry are called Cry proteins. Organism that produces Cry proteins is Bacillus thuringiensis.
The cry genes are incorporated in several crop plants, which then develop resistance to a specific targeted pest, e.g. cry IAc and cry IIAb control the cotton bollworms and cry LAb controls corn borer.

Question 18.
Expand GMO. How is it different from a hybrid?
Answer:
GMO stands for Genetically Modified Organism.
It differs from a hybrid because in a hybrid, cross is done between total genomes of two species or strains, whereas in a GMO, foreign genes from entirely dilferent species are introduced in the organism and are usually maintained as extrachromosomal entity or are integrated into the genome of the organism.

Question 19.
Describe any three potential applications of genetically modified plants.
Answer:
Potential applications of genetically modified plants are

• Nutritional enhancement, e.g vitamin-A enriched rice.
• Stress tolerance crops are more tolerant to abiotic stresses such as cold, drought, etc.
• Creation of tailor made plants by using GM plants to supply alternative resources to industries in the form of starches, biofuels, etc.

Question 20.
What is meant by transgenic animals?
Answer:
Animals that have had their DNA manipulated to possess and express an extra (foreign) gene are known as transgenic animals, e.g. transgenic rats, rabbits, pigs, sheep, cows and fish. Over 95% of all the existing transgenic animals are mice. The gene that is being transferred is called transgene.

Question 21.
Comment on how transgenic animals have proved to be beneficial in
(i) Production of biological products?
(ii) Chemical safety testing?
Answer:
(i) The transgenic animals have been proved to be beneficial in the production of biological products like human protein α-1 antitrypsin (by coding genes from that protein only), in the treatment of emphysema and production of human protein (α-lactalbumin) enriched milk by transgenic cow, i.e. Rosie. This milk was more nutritionally balanced for human beings than natural cow’s milk.
(ii) Transgenic animals are studied for testing toxicity of drugs and other chemicals as they carry genes that make them more sensitive to toxic substances.

Question 22.
What is the utility of transgenic animals?
Or
With respect to understanding diseases, discuss the importance of transgenic animal models.
Answer:
Transgenic animals are important in the following fields
(i) They are being used in basic science research to elucidate the role of genes in the development of diseases like cancer, cystic fibrosis, rheumatoid arthritis and Alzheimer’s disease.
(ii) They are valuable tools in the drug development process itself.
(iii) Milk producing transgenics can produce medicines or human proteins (insulin, growth hormone, etc.) in large quantities.
(iv) Transgenics can be a source of transplant organs as well.

Question 23.
(i) Which animals are being used for testing the safety of vaccines? Name the vaccine for which trials are going on.
(ii) Name the first transgenic cow. Why is it important?
Answer:
(i) Transgenic mice are used for testing the safety of vaccines.
The trials are going on for polio vaccine.
(ii) Rosie was the first transgenic cow. It is important because it produces human protein enriched milk, even better than a natural cow’s milk.

Question 24.
(i) Explain alpha lactalbumin. Where is it produced in human body?
(ii) In what manner biotechnology has helped in production of more nutritionally balanced milk?
Answer:
(i) Alpha lactalbumin is a human milk protein which helps to increase the production of lactose in the body. It is produced in human milk.
(ii) Biotechnology has lead to production of transgenic cow, Rosie that produced around 2.4 g/L human protein enriched milk. This milk contained the human alpha lactalbumin and was nutritionally more balanced than a natural cow’s milk.

Question 25.
While creating genetically modified organisms, genetic barriers are not respected. How can this be dangerous in the long run?
Answer:
Genetic modification of organisms can have unpredictable results when such organisms are introduced into the ecosystem. Because the real effects of gene manipulation are visible only when such organisms interact with other components and organisms of the ecosystem.

Question 26.
Biopiracy should be prevented. State why and how?
Answer:
Biopiracy should he prevented because
(i) The countries and people concerned are not given adequate compensatory payment.
(ii) The countries/people also lose their right to grow and use breeding experiments to improve the other varieties of the same species.
It may be prevented by implementing specific laws that takes into consideration all the biopatents and biopiracy related issues.

Question 27.
State the initiative taken by the Indian Parliament against biopiracy.
Answer:
The Indian Parliament has recently passed the second amendment to the Indian Patents Bill that takes action against biopiracy. In India, the Patent Act was enacted in 1970 to protect their resources and traditional knowledge from being exploited by other countries.
This act has undergone many amendments in 1999, 2002, 2005 and 2006. The Indian biosafety network is headed by the Department of Biotechnology.

Question 28.
Write a self-explanatory note on biopatent.
Or What is patent?
Answer:
When an individual develops a new product or process innovation using his intellect, the innovation becomes his own. Various rules at national and international lands protects the misuse of this innovation, and also safeguards the rights of the innovater.
The new inventions can be safe protected by patents, design trademark, trade secrets and copy rights, etc.

It is a set of exclusive legal rights granted by a government to the inventors or their assignee for a limited period of time to prevent others from commercial use of their invention. When patent is granted for biological entities and for products derived from them, they are called biopatents. Primarily USA, Japan and members of European Union are awarding biopatents.

Question 29.
Name a set of principles that may be used to regulate human activities in relation to the biological world. Why are they important?
Answer:
A set of principles that may be used to regulate human activities in relation to the biological world are called bioethics.
These are important because the genetic modification of an organism can have unpredictable results when such organisms are introduced into the ecosystem.

Question 30.
What is meant by biopiracy?
Answer:
It refers to the use of bioresources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment. The majority of industrialised nations are financially rich but poor in biodiversity and traditional knowledge, in comparison to developing and underdeveloped countries.

Another cause of biopiracy is bioprospecting which means a thorough survey of a source material to expand the knowledge and applications in biotechnology. During the course of bioprospecting, scientists may transfer any biological resource which they may consider as novel.

Differentiate between the following (for complete chapter)

Question 1.
Herbicide resistant plants and Frost resistant plants.
Answer:
Differences between herbicide resistant plants and frost resistant plants are as follows

Herbicide resistant plants	Frost resistant plants
Generated by transferring bacterial herbicide resistant gene into plant cells.	Generated by deleting a gene that promotes ice nucleation.
e.g. Petunia contains glyphosate resistant gene which is being isolated to generate glyphosate resistant plants.	e.g. Pseudomonas syringae contains gene promoting ice nucleation. It is deleted by genetic engineering to produce ice minus strain.

Question 2.
Humulin and Wosulin.
Answer:
Differences between humulin and wosulin are as follows

Humulin	Wosulin
Manufactured by Eli Lilly corporation, USA.	Manufactured by wokhardt limited India.
First recombinant drug approved by FDA for human use.	General drug to treat diabetes.

Question 3.
Ex vivo gene therapy and In vivo gene therapy.
Answer:
Differences between Ex vivo gene therapy and In vivo gene therapy are as follows.

Ex vivo gene therapy	In vivo gene therapy
The cells are removed from the patient and genetic material is inserted in them in vitro, prior to transplantation of modified cells.	The genetic material is transferred directly into cells within a patient.
This approach is applicable to tissues that can be removed from the body and returned later and survive for longer period of time, e.g. hematopoietic cells.	It is only possible in tissues where the individual cells cannot be cultured in vitro in sufficient numbers or where cultured cells cannot be efficiently reimplanted, e.g. brain cells.

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 12 Principles and Processes of Biotechnology Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 12 Principles and Processes of Biotechnology

Principles and Processes of Biotechnology Class 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
GAATTC is the recognition site for which of the following restriction endonucleases?
(a) Hind III
(b) Eco RI
(c) Bam I
(d) Hae III
Answer:
(b) Eco RI

Question 2.
Given below is a sample of a portion of DNA strand giving the base sequence on the opposite strands. What is so special shown in it?
(a) Replication completed
(b) Deletion mutation
(c) Start codon at the 5′ end
(d) Palindromic sequence
Answer:
(d) Palindromic sequence

Question 3.
Agarose extracted from sea weeds is used in
(a) spectrophotometer
(b) tissue culture
(c) PCR
(d) gel electrophoresis
Answer:
(d) gel electrophoresis

Question 4.
The blotting of RNA is called
(a) Northern blot
(b) Southern blot
(c) Western blot
(d) Eastern blot
Answer:
(a) Northern blot

Question 5.
Eco RI cleaves the DNA strands to produce
(a) blunt ends
(b) sticky ends
(c) satellite ends
(d) ori replication end
Answer:
(b) sticky ends

Question 6.
DNA fragments generated by the restriction endonucleases in a chemical reaction can be separated by
(a) electrophoresis
(b) restriction mapping
(c) centrifugation
(d) polymerase chain reaction
Answer:
(a) electrophoresis

Question 7.
Commonly used vectors for human genome sequencing are
(a) T-DNA
(b) BAC and YAC
(c) expression vector
(d) T/A cloning vectors
Answer:
(b) BAC and YAC

Question 8.
Which procedure is followed for amplification of DNA?
(a) Electrophoresis
(b) Autoradiography
(c) Polymerase chain reaction
(d) Southern blotting
Answer:
(c) Polymerase chain reaction

Question 9.
The Polymerase Chain Reaction (PCR) is a technique that is used for
(a) in vivo replication of specific DNA sequence using thermostable DNA polymerase
(b) in vitro synthesis of mRNA
(c) in vitro replication of specific DNA sequence using thermostable DNA polymerase
(d) in-vivo synthesis of mRNA
Answer:
(c) In-vitro replication of specific DNA sequence using thermostable DNA polymerase.

Question 10.
The figure below shows three steps (A, B, C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents?

(a) B – denaturation at a temperature of about 98°C separating the two DNA strands
(b) A – denaturation at a temperature of about 50°C
(c) C – extension in the presence of heat stable DNA polymerase
(d) A – annealing with two sets of primers
Answer:
(a) B – denaturation at a temperature of about 98°C separating the two DNA strands.

Question 11.
In recombinant DNA technique, the term vector refers to
(a) plasmids that can transfer foreign DNA into a living cell
(b) cosmids that can cut DNA at specific base sequence
(c) plasmids that can join different DNA fragments
(d) cosmids that can degrade harmful proteins
Answer:
(a) plasmids that can transfer foreign DNA into a living cell

Question 12.
The rDNA molecule is introduced into the cell of bacterium with the help of.
(a) restriction endonuclease
(b) DNA ligase
(c) electroporation
(d) None of the above
Answer:
(a) restriction endonuclease

Question 13.
The bacterial source of Hpa I is
(a) Haemophilus influenzae
(b) Bacillus amyloliquefaciens
(c) Providentcia stuarth
(d) Haemophilus parainfluenzae
Answer:
(d) Haemophilus parainfluenzae

Question 14.
Klenow fragment does not possess
(a) 5′ → 3′ exonuclease
(b) 3′ → 5′ exonuclease
(c) polymerase
(d) All of the above
Answer:
(a) 5′ → 3′ exonuclease

Correct the statements, if required, by changing the underlined word(s)

Question 1.
Restriction enzymes are used to cut single-stranded DNA.
Answer:
double-stranded DNA.

Question 2.
‘CO’ part in Eco RI stands for coenzyme.
Answer:
coli.

Question 4.
The first isolated restriction endonuclease was Hind III.
Answer:
Eco RI

Question 5.
DNA ligase forms phosphodiester bonds to ligate the DNA fragments.
Answer:
It is correct

Question 6.
Plasmids present in bacterial cells are linear double helical DNA molecules.
Answer:
circular

Question 7.
Taq polymerase is used between annealing and denaturation during PCR.
Answer:
extension.

Question 8.
A hybrid of plasmid and phage is YAC.
Answer:
BAC

Question 9.
Bacteria phage are autonomously replicating circular DNA.
Answer:
Bacteriophage

Fill in the blanks

Question 1.
DNA polymerase can be obtained from ……….. .
Answer:
Thermus aquaticus

Question 2.
The usual source of restriction endonuclease used in gene cloning is ………….. .
Answer:
bacteria .

Question 3.
Other than E. coli ………….. bacteria is used in recombinant DNA technology.
Answer:
Salmonella typhimurium.

Question 4.
First letter of restriction enzymes represents …………. .
Answer:
genus

Question 5.
Alkaline phosphatase is ………. an enzyme.
Answer:
DNA ligase

Question 6.
The vector for T-DNA is ………….. .
Answer:
Agrobacterium tumefaciens.

Question 7.
In biolistic method ………….. particles coated with foreign DNA are bombarded into target cells.
Answer:
gold or tungesten.

Question 8.
……………. is most commonly used process of foreign DNA injection in animal cells.
Answer:
Microinjection

Question 9.
…………. helps in selecting transformants and eliminating non-transformants.
Answer:
Conventional method

Express in one or two word(s)

Question 1.
Molecular scissors used in recombinant technology are known as
Answer:
restriction enzymes.

Question 2.
Which enzyme helps in joining DNA fragments?
Answer:
DNA ligase.

Question 3.
Name the process of transfer of protein molecules onto a membrane.
Answer:
Western blotting

Question 4.
Single-stranded fragments are transferred onto nitrocellulose filter paper by which process?
Answer:
Northern blotting

Question 5.
Name the bacterium that yields thermostable DNA polymerases.
Answer:
Thermus aquaticus

Question 6.
What is particle gun?
Answer:
It is a technique of bombarding microparticles of gold or tungsten with foreign DNA into target cell with high velocity.

Question 7.
Name one chemical that helps foreign DNA to enter host cell.
Answer:
Transformation

Short Answer Type Questions

Question 1.
Write a short note on genetic engineering.
Answer:
Genetic engineering is a modification, of chemical nature of genetic material (DNA/RNA) and their introduction into another organism to change the phenotypic characters of that organism.
This involves recombinant nucleic acid (DNA or RNA) techniques to form new combinations of heritable genetic material followed by the incorporation of material indirecdy through vectors or directly through microinjection and other techniques.

Question 2.
What are restriction enzymes? Mention their functions in recombinant DNA technology.
Answer:
The enzymes used for cutting the DNA during recombinant DNA technology are called restriction enzymes.
Restriction enzymes function as chemical knives or molecular scissors in genetic engineering. It recognises specific nucleotide sequence and makes cuts.

Question 3.
(i) Mention the difference in the mode of action of exonuclease and endonuclease.
(ii) How does restriction endonuclease function?
Answer:
(i) Exonucleases cleave base pairs of DNA at their terminal ends (either 5′ or 3 0 while, the endonucleases cleave DNA at any point within DNA segment at specific position except terminal ends.

(ii) Restriction endonuclease Eco RI cuts the DNA strands a little away from the palindromic sequences, but between the same two bases on the two strands

Question 4.
How are ‘sticky ends’ formed on a DNA strand? Why are they so called?
Or
A recombinant DNA is formed when sticky ends of the vector DNA and the foreign DNA join. Explain how sticky ends are formed and get joined?
Answer:
Restriction enzymes cut the strands of the DNA, a little away from the centre of the palindromic sites, but between the same two bases on opposite strands. This leaves sticky single-stranded position at the ends. These overhanging stretches are called ‘sticky ends’. These are named so, because they form hydrogen bonds with their complementary cut counterparts.

Question 5.
What does Hind and ‘III’ refer to in the enzyme Hind III?
Answer:

1. The first letter ‘H indicates the genus of the organism, from which the enzyme was isolated, i.e. H-genus, Haemophilus.
2. The roman number (III) denotes the sequence in which the restriction endonuclease from that particular genus, species and strain of bacteria have been isolated, i. e., third restriction endonuclease to be isolated from this species.

Question 6.
Collect five examples of palindromic DNA sequences by consulting your teacher. Better try to create a palindromic sequence by following base pair rules.
Answer:

Question 7.
Restriction enzymes should not have more than one site of action in the cloning site of a vector. Comment.
Answer:
Enzymes should not have more than one site of action.
This is because vectors have very few recognition sites for commonly used restriction enzymes.
If it will have more than one restriction sites it will generate various fragments. This will complicate the process of genetic engineering.

Question 8.
Draw agarose gel electrophoresis apparatus. Description is not required.
Answer:

(a) Agarose gel apparatus, (b) Fluorescent bands on the agarose gel slab containing resolved DNA fragments with differing molecular weights.

Question 9.
A mixture of fragmented DNA was electrophoresed in an agarose gel. After staining the gel with ethidium bromide, no DNA bands were observed. What could be the reason?
Answer:
DNA bands may not be observed when a mixture of fragmented DNA was electrophoresed, due to following reasons

1. Concentration of agarose in the gel was not proper, as greater the concentration of agarose gel used, the greater will be separation of small DNA fragments, whereas smaller the concentration of agarose, higher will be the resolution of bands.
2. If the concentration of salt in the buffer was not proper.
3. If DNA sample is contaminated with RNA or any other impurity or if the concentration of DNA is too low.

Question 10.
Name and describe the technique that helps in separating the DNA fragments by the use of restriction endonuclease.
Or
(i) Name the technique used for the separation of DNA fragments.
(ii) Write the type of matrix used in this technique.
(iii) How is the prepared DNA visualised and extracted for use in recombinant technology?
Answer:
(i) DNA fragments can be separated by the technique called gel electrophoresis.
(ii) The most commonly used matrix is agarose gel, which is a natural polymer extracted from sea weeds.
(iii) A compound called Ethidium Bromide (EtBr) stains DNA, which on exposure with ultraviolet radiationals gives orange light. Hence, DNA fragments appear as orange bands.

Question 11.
A plasmid DNA and a linear DNA (both of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band while, linear DNA shows two fragments. Explain.
Answer:
This is because plasmid is a circular DNA molecule.
When cut with enzyme, it becomes linear, but does not get fragmented. Whereas, a linear DNA molecule gets cut into two fragments. Hence, a single DNA band is observed for plasmid while, two DNA bands are observed for linear DNA in agarose gel.

Question 12.
Write the role of ‘ori’ and ‘restriction site’ in a cloning vector pBR322.
Answer:
Ori is the site where replication starts. This site is responsible for controlling the copy number of a vector. Restriction site is the site of ligation of alien/foreign DNA in the vector, in one of the two antibiotic resistance sites or coding sequence of β- galactosidase.

Question 13.
Write a short note on plasmids.
Answer:
These are small and double-stranded extrachromosomal DNA molecules having an origin of replication. They occur naturally in bacteria. Naturally occurring plasmids are not suitable for the cloning of genes. They are genetically engineered and made suitable for cloning.

Such plasmids are called cloning plasmids. A suitable cloning plasmid should preferably have the following properties

• It should be non-conjugative.
• It should have a relaxed replication and a high copy number.
• It should have an origin of replication.
• It should have unique restriction sites.
• It should have antibiotic marker gene for selection.

The most common cloning plasmid is designated as pBR322, where p stands for the word plasmid and B and R signify the names of its engineers (B. Boliver and R. Rodriguez) 322 is a numerical designation that has a relevance to these workers, who worked out the plasmid.

Question 14.
You have chosen a plasmid as vector for cloning your gene. However, this vector plasmid lacks a selectable marker. How would it affect your experiment?
Answer:
In a gene cloning experiment, first a recombinant DNA molecule is constructed, where the gene of interest is ligated to the vector and introduced inside the host cell (transformation). Since, not all the cells gets transformed with the recombinant/plasmid DNA, in the absence of selectable marker, it will be difficult to distinguish between transformants and non-transformants. Because the role of selectable marker is in the selection of transformants.

Question 15.
Draw a schematic sketch of pBR322 plasmid and label the following in it.
(i) Any two restriction sites
(ii) Ori and rop genes
(iii) An antibiotic resistant gene
Answer:
The labelled diagram of pBR322 plasmid is shown in the figure with
(i) Eco RI and Bam HI as restriction enzymes
(ii) Ori and rop genes
(iii) amp^R (an antibiotic resistant gene)

E. coli cloning vector pBR322

Question 16.
(i) How are recombinant vectors created?
(ii) For creating one recombinant vector only one type of restriction endonuclease is required. Give reason.
Answer:
(i) The vector DNA is cut at a particular restriction site using a restriction enzyme (to cut the desired DNA segment). The alien DNA is then linked with the plasmid DNA using an enzyme called ligase to form the recombinant vector.

(ii) Since, a restriction enzyme recognises and cuts the DNA at a particular sequence is called recognition site, the same restriction enzyme is used for cutting the DNA segment from both the vector and the other source to achieve as ends.

Question 17.
How bacterial cells are made competent to take up DNA?
Or
Describe the role of CaCl₂ in the prepration of competent cell.
Answer:
Since, DNA is a hydrophilic molecule, it cannot pass through the cell membranes. In order to force bacteria to take up the plasmid, the bacterial cells must first be made competent to take up foreign DNA. This is done by treating them with a specific concentration of a divalent cation such as calcium (Ca²⁺), which increases the efficiency with which DNA enters the bacterium through the pores in its cell wall.

Recombinant DNA can then be forced into such cells by incubating the cells with recombinant DNA on ice, followed by placing them briefly at 42°C (heat shock), and then putting them back on ice. This enables the bacteria to take up the recombinant DNA.

Question 18.
PCR is a useful tool for early diagnosis of an infectious disease. Comment.
Answer:
PCR is a very sensitive technique, which enables the specific amplification of desired DNA from a limited amount of DNA containing sample. Hence, it can detect the presence of an infectious organism in the patient at an early stage of infection (even before the infectious organism has multiplied to large number).

Question 19.
(i) Explain how to find whether an E coli bacterium has transformed or not, when a recombinant DNA bearing ampicillin-resistance gene is transferred into it
(ii) What does the ampicillin-resistant gene act as, in the above case?
Answer:
(i) The recombinant/transformant can be selected out from the non-recombinants/ non-transformants by plating the transformants on ampicillin-containing medium. The transformants will grow in it, while the non-transformants will not grow.
(ii) It acts as a selectable marker.

Question 20.
Name the source of the DNA polymerase used in PCR technique. Mention, why it is used ?
Or
Give the name of the organism from where the thermostable DNA polymerase is isolated. State its role in genetic engineering.
Answer:
Bacterium Thermus aquaticus is a source of enzyme Taq polymerase. As, it is a thermostable enzyme and works at high temperature, it is used to amplify DNA in vitro by PCR. The amplified fragment of desired DNA can be used to ligate with the vector for further cloning.

Question 21.
Rearrange the following in the correct sequence to accomplish an important biotechnological reaction
(a) In vitro synthesis of copies of DNA of interest
(b) Chemically synthesised oligonucleotides
(c) Enzyme DNA polymerase
(d) Complementary region of DNA
(e) Genomic DNA template
(f) Nucleotides provided
(g) Primers
(h) Thermostable DNA-polymers (From Thermus aquaticus)
(i) Denaturation of dsDNA
Answer:

(i) Denaturation of dsDNA
↓
(e) Genomic DNA template
↓
(g) Primers
↓
(b) Chemically synthesised oligonucleotides
↓
(d) Complementary region of DNA
↓
(f) Nucleotides provided
↓
(c) Enzyme DNA polymerase
↓
(h) Thermostable DNA polymerase (from Thermus aquaticus )
↓
(a) In vitro synthesis of copies of DNA of interest

Question 22.
While doing a PCR, denaturation step is missed. What will be its effect on the process?
Answer:
If denaturation of double-stranded DNA does not take place, then primers will not be able to anneal to the template. Amplification will not occur and no extension will take place.

Question 23.
A schematic representation of PCR up to the extension stage is given below. Give answers of the following questions.

(i) Name the process A
(ii) Identify B.
(iii) Identify C and mention its importance in PCR.
Answer:
(i) A – Denaturation process
(ii) B – Primers
(iii) C – Taq DNA polymerase.
Taq polymerase is a thermostable enzyme, which remains active during the high temperature and induces denaturation of DNA.

Differentiate between the following (for complete chapter)

Question 1.
Exonucleases and Endonucleases.
Answer:
Differences between exonucleases and endonucleases are as follows

Exonucleases	Endonucleases
Remove nucleotide from the outer ends of the DNA.	Make cuts at specific positions within the DNA.
It makes cut at only one of the two strands of DNA.	It makes cuts at both strands of DNA simultaneously.
e.g., snake venom and spleen phosphodiesterase.	e.g., deoxyribonuclease 1 and II.

Question 2.
Plasmid and Chromosomal DNA.
Answer:
Differences between plasmid and chromosomal DNA are as follows

Plasmid DNA	Chromosomal DNA
Extrachromosomal circular DNA.	Generally linear.
Not associated with histone proteins.	Associated with histone proteins.
Contains very few genes, but may not be necessary for the cell.	It Consists of complete genome vital for the cellular functions.
Replicates independently.	Replicates with genome.

Question 3.
Electroporation and Microinjection.
Answer:
Differences between electroporation and microinjection are as follows

Electroporation	Microinjection
In this method, electric field is applied to cells in order to increase the permeability of the cell membrane, allowing DNA to be introduced into the cell.	This is a vectorless method of direct delivery of recombinant DNA into plant and animal cells.
In this, brief pulses of high voltage electric currents are passed through the medium.	The foreign DNA is delivered into the nucleus with the help of microinjection or micropipette.
This procedure is mostly used for transforming plant protoplasts.	This method is particularly used for mammalian cells.

Question 4.
Type-I endonuclease and Type II endonuclease.
Answer:
Differences between type-I endonuclease and type-II endonuclease are as follows

Type-I endonuclease	Type-II
They consist of 3 different subunits.	They are structurally simple.
Require ATP, Mg2+, S-adenosyl-methionine for restriction.	Required Mg2+; for restriction.
Recognise specific sequences, but do not cut these sites.	Recognise specific sites and cut them.

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 11 Microbes in Human Welfare Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 11 Microbes in Human Welfare

Microbes in Human Welfare Class 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
The bacterium that converts milk into curd is ………. .
(a) Lactobacillus
(b) Azotobacter
(c) Rkizobium
(d) Clostridium
Answer:
(a) Lactobacillus

Question 2.
Fermentation of milk sugar, ……… is done by Lactobacillus.
(a) glucose
(b) fructose
(c) sucrose
(d) lactose
Answer:
(d) lactose

Question 3.
The antibiotic chloramphenicol can be obtained from the bacterium ……. .
(a) Streptomyces griseus
(b) S. aureofaciens
(c) S. venezuelae
(d) S. noursei
Answer:
(c) Streptomyces venezuelae

Question 4.
Acetobacter is involved in the production of
(a) citric acid
(b) acetic acid
(c) gluconic acid
(d) fumaric acid
Answer:
(b) acetic acid

Question 5.
Yeast and Acetobacter are both involved in the production of ……… from carbohydrates.
(a) penicillin
(b) citrate
(c) methane
(d) vinegar
Answer:(d) vinegar

Question 6.
Lipase enzyme is produced by the activity of
(a) Trichoderma viride
(b) Rhizopus sp.
(c) Aspergillus sp.
(d) None of these
Answer:
(b) Rhizopus sp.

Question 7.
The secondary treatment of sewage includes
(a) biological treatment
(b) chemical treatment
(c) filtration
(d) All of the above
Answer:
(a) biological treatment

Question 8.
In primary treatment of sewage, non-biodegradable particles are removed through a process of …………. .
(a) sedimentation
(b) sterilisation
(c) chemical treatment
(d) biological treatment
Answer:
(a) sedimentation

Question 9.
In secondary treatment of sewage in open bioreactors, the microorganisms grow and multiply to form ………. .
(a) manure
(b) compost
(c) sludge
(d) sediment
Answer:
(c) sludge

Question 10.
Milk enzyme that coagulates during curd formation is
(a) protease
(b) casein
(c) rennin
(d) pectinase
Answer:
(c) rennin

Question 11.
Name the bacterium, which produces Swiss cheese.
(a) Saccharomyces cerevisiae
(b) Propionibacterium shermanii
(c) Penicillium roqueforti
(d) Lactobacillus
Answer:
(b) Propionibacterium shermanii

Question 12.
Nystatin is obtained from
(a) Penicillium sp.
(b) Streptomyces griseus
(c) Streptomyces noursei
(d) Aspergillus sp.
Answer:
(c) Streptomyces noursei

Question 13.
The raw material used for the production of wine is
(a) grapes
(b) barley grain
(c) vinegar
(d) None of these
Answer:
(a) grapes

Question 14.
During commercial production of vinegar, secondary fermentation occurs under
(a) anaerobic conditions
(b) aerobic conditions
(c) Both (a) and (b)
(d) unfavourable conditions
Answer:
(b) aerobic conditions

Question 15.
The bacterium which acts on bio-waste to produce biogas is
(a) Methanobacterium
(b) Trichoderma
(c) Bacillus thuringiensis
(d) Azotobacter
Answer:
(a) Methanobacterium

Question 16.
The principal component of biogas is ……….. .
(a) hydrogen
(b) carbon dioxide
(c) ozone
(d) methane
Answer:
(d) methane

Question 17.
Which one of the following microbes is used as biocontrol agent?
(a) Papilloma virus
(b) Baculovirus
(c) Herpes virus
(d) Pox virus
Answer:(b) Baculovirus

Question 18.
Biopesticides are preferred over chemical pesticides due to their
(a) high pest specificity
(b) biodegradability
(c) non-biodegradability
(d) Both (a) and (b)
Answer:
(d) high pest specificity and biodegrdability

Question 19.
Which one of the following fungi makes symbiotic association with the plants?
(a) Glomus
(b) Nostoc
(c) BGA
(d) Rhizobium
Answer:
(a) Glomus

Question 20.
Which one of the following organisms has been commercialised as blood cholesterol lowering agent?
(a) Trichoderma polysporum
(b) Monascus purpureus
(c) Saccharomyces cerevisiae
(d) Aspergillus niger
Answer:
(b) Monascus purpureus

Question 21.
Which one of the following is mainly produced by the activity of anaerobic bacteria on sewage?
(a) Mustard gas
(b) Biogas
(c) Laughing gas
(d) Propane
Answer:
(b) Biogas

Question 22.
Secondary sewage treatment is mainly a
(a) chemical process
(b) biological process
(c) physical process
(d) mechanical process
Answer:
(b) biological process

Question 23.
Organisms called methanogens are most abundant in a
(a) polluted stream
(b) hot spring
(c) sulphur rock
(d) rumen of these
Answer:
(d) rumen of these

Question 24.
A biofertiliser is
(a) Rhizobium
(b) Azotobacter
(c) Nostoc
(d) All of these
Answer:
(d) All of these

Fill in the blanks

Question 1.
Roquefort cheese is ……….. by growing a specific ………… on it.
Answer:
ripened, fungus

Question 2.
The enzyme ……… is used in detergent formulations to remove oily stains from the laundry.
Answer:
lipase

Question 3.
The ……… from secondary treatment of sewage is generally released into ………. water bodies.
Answer:
effluent, natural

Question 4.
During sewage treatement, aerobic microbes are converted into mesh-like structure called ……………. .
Answer:
floes

Question 5.
Species of ………. is used for production of roquefort cheese.
Answer:
Penicillium

Question 6.
………. is an antibiotic that was used to treat soldiers during World War II.
Answer:
Penicillin

Question 7.
………. enzyme produced by Aspergillus niger is used for clarifying bottled juices.
Answer:
Pectinase

Question 8.
…………. is used as a blood cholesterol lowering agent.
Answer:
Statins

Question 9.
During the secondary treatment of primary effluents, the BOD level ……….. .
Answer:
decreases

Question 10.
During sludge digestion, bacteria produce gases like …………. .
Answer:
CH₄,H₂S, CO₂

Question 11.
The technology of biogas production was developed in India by ……….. .
Answer:
Khadi and Village Industries Commision (KVIC)/Indian Agricultural Research Institute (IARI).

Question 12.
The use of biological methods for controlling plant diseases and pests is called ……….. .
Answer:
biocontrol

Question 13.
…………. are used as biocontrol agents to get rid of moquitoes.
Answer:
Dragonflies

Question 14.
Baculovirus is a rod-shaped ………….. DNA virus.
Answer:
double-stranded

Question 15.
Rhizobium is a ………. bacteria that serves as biofertiliser.
Answer:
symbiotic

Question 16.
The first antibiotic was discovered by ………… .
Answer:
Alexander Fleming

Question 17.
……….. are used in biological control of aphids.
Answer:
Ladybirds

Question 18.
Azospirillum and Azotobacter are ………… bacteria.
Answer:
free-living

Question 19.
Plants with mycorrhizal association show tolerance to …………. and ……….. .
Answer:
salinity, drought

Correct the statement, if required, by changing the underlined word(s)

Question 1.
Antibiotic tetracyclin is obtained from Penicillium notatum.
Answer:
Streptomyces aureofaciens

Question 2.
The first antibiotic to be extracted from bacterial culture was nystatin.
Answer:
streptomycin

Question 3.
In ethyl alcohol production, the unicellular fungus, Penicillium is used.
Answer:
Saccharomyces cerevisiae

Question 4.
Acetic acid is produced by Lactobacillus sp.
Answer:
Acetobacter

Question 5.
In the secondary treatment of sewage, unwanted coarse, non-biodegradable particles are removed.
Answer:
primary treatment

Question 6.
Biogas production technology was developed in India mainly by NBRI and CDRI.
Answer:
KVIC, IARI

Question 7.
Methanogens are present in the liver of cattle.
Answer:
rumen

Question 8.
The major component of biogas is carbon dioxide.
Answer:
methane

Question 9.
Nostoc is present in root nodule of leguminous plants and fixes atmospheric nitrogen.
Answer:
Rhizobium

Question 10.
Biopesticides are non-biodegradable compounds.
Answer:
biodegradable

Question 11.
In paddy fields, blue-green algae fix phosphorus to enrich the soil fertility.
Answer:
nitrogen

Question 12.
Bacillus thuringiensis is a Gram-negative bacteria.
Answer:
positive

Question 13.
Baculoviruses are single-stranded RNA viruses.
Answer:
double-stranded DNA

Question 14.
Mycorrhizae provide cobalt to the roots of plants.
Answer:
phosphorus

Question 15.
Microorganisms belonging to the genus-Penicillium are used as agents of biological control.
Answer:
Nucleopolyhedrovirus

Express in one or two word (s)

Question 1.
The drink produced by fermentation of sap of palm tree.
Answer:
Toddy

Question 2.
The source of antibiotic streptomycin.
Answer:
Streptomyces griseus

Question 3.
Name the molecules which are used as blood cholesterol lowering agents?
Answer:
Statins

Question 4.
An enzyme used for the clarifying bottled fruit juice.
Answer:
Pectinase

Question 5.
Which organic acid gets converted into methane in the final step of biogas production?
Answer:
Acetate

Question 6.
Name a bacterium used as biopesticide.
Answer:
Bacillus thuringiensis.

Question 7.
Give an example of free-living fungi present in root ecosystem.
Answer:
Trichoderma

Question 8.
Name any two major components of biogas.
Answer:
CH₄ and CO₂

Question 9.
Name any one biocontrol agent.
Answer:
Baculovirus

Question 10.
A cheese with large holes produced by Propionibacterium shermanii.
Answer:
Swiss cheese

Question 11.
Name any two cyanobacteria used as biofertilisers
Answer:
Nostoc and Anabaena

Short Answer Type Questions

Question 1.
Write a note on fermentation by microbes and its two applications.
Or
Write a short note on fermentation.
Answer:
Fermentation is the process of conversion of carbohydrates to alcohol and CO₂ by some microorganisms in the absence of O₂. Microbes via fermentation are utilised for the synthesis of a number of products valuable for human beings.

Some of the applications of microbes are

• Production of bread using baker’s yeast.
• Wine, beer and other alcoholic drinks are produced by fermentation.

Question 2.
Mention a product of human welfare obtained with the help of each one of the following microbes.
(i) LAB
(ii) Saccharomyces cerevisiae
(iii) Propionibacterium shermanii
(iv) Aspergillus niger
Answer:

Microbe	Product of human welfare
(i) LAB	Curd
(ii) Saccharomyces cerevisiae	Bread, cakes, wines, beer
(iii) Propionibacterium shermanii	Swiss cheese
(iv) Aspergillus niger	Citric acid

Question 3.
How are fermented beverages prepared?
Or
Write a note on alcoholic beverages.
Answer:
Fermented beverages include wine, beer, whisky, brandy and rum which are obtained by fermenting malted cereals and fruit juices with Saccharomyces cerevisiae or ‘ brewer’s yeast to produce ethanol.

The production of variety of alcoholic drinks depends on the type of raw material used and the’type of processing, e.g. wine and beer are produced without distillation. Whisky, brandy and rum are produced by the distillation of the fermented broth.

Question 4.
How streptomycin is obtained?
Answer:
Streptomycin is an antibiotic that is obtained from Streptomyces griseus. The bacteria are cultured on medium containing glucose, soyameal and mineral salts. The pH of the medium is maintained at 7.4 -7.5. The fermentation is carried out under submerged condition for 5-7 days. It is done at 25-30° C.

Question 5.
Write a short note on alcoholic fermentation.
Answer:
Earlier, people used to produce alcohol by fermentation. Later, another method was used for the same which included catalytic hydration of ethylene. In modern time, again fermentation process is used for the production of ethanol.

It is used for dual purpose, i.e. as chemical and as fuel. Sugar-beet, potatoes, corn, cassava and sugarcane, etc., are used as substrate for the production of ethanol.

Yeasts (like Saccharomyces cerevisiae, S. uvarum, S. carlsbergensis), Candida brassicae, C. utilis and bacteria (Zymomonas mobilis) are used for the production of ethanol at industrial scale. The type’of alcoholic drink depends upon the raw material used for its production.
Beer is obtained by the fermentation of barley grains while wine is produced by grapes. This process of alcohol production is known as brewing. In this process, CO₂ is produced as a byproduct which is further

Question 6.
What are anaerobic sludge digesters?
Answer:
Sludge is the remaining part of organic matter after secondary treatment of sewage. In sludge digesters, other kinds of bacteria, which grow anaerobically, digest the bacteria and the fungi present in the sludge. During this process, bacteria produce a mixture of gases, such as methane, hydrogen sulphide and carbon dioxide which form biogas. It can be used as a source of energy.

Question 7.
Write a short note on secondary treatment of sewage.
Answer:
Secondary treatment of sewage is as follows
(i) This treatment is also known as biological treatment because it involves the use of microbes or biota for the treatment of sewage. The effluent from primary treatment is passed into large aeration tanks, where it is constantly mechanically agitated and air is pumped into it.

(ii) This air helps in the growth of useful aerobic, microbes into floes (masses of bacteria associated with fungal filament to form mesh like structures). The growth of microbes consumes major part of the organic matter, converting it into microbial biomass and releasing lot of minerals. This significantly reduces the BOD (Biochemical Oxyen Demand) of the water.

Question 8.
Write a short note on biogas.
Ans.
It is a complex mixture of gases, like CH₄, CO₂ and H₂, but its major content is methane gas. It is produced by the microbial activity during anaerobic digestion of biomass. Biogas is used as fuel. The type of gas produced by microbes during their growth and metabolism depends upon the microbes and the organic substrates they utilise. Certain bacteria, which grow anaerobically on cellulosic material, produce large amount of methane gas along with CO₂ and H₂ by the process called methanogenesis.

These bacteria are called methanogens and one such common bacterium is Methanobacterium. Methanogens produce large amount of biogas which contains about 50-70% CH₄, 30-40% CO₂, 1-5% H₂ and 0.01% oxygen.

Question 9.
Write a short note on biocontrol agents.
Answer:
Biocontrol agents involve the use of biological methods for controlling plant diseases and pests. Bacteria, fungi and viruses can act as biocontrol agents.
These microbes reduce the target species population through many ecological mechanisms, including pathogenicity, competition, production of chemicals and other interactions.

Question 10.
Write a short note on Bacillus thuringiensis (Bt).
Answer:
Bacillus thuringiensis is a soil-borne, Gram-positive bacterium. It is used to create a transgenic crop plant having resistance to several diseases. The genes encoding for insecticidal properties in the bacterium are isolated and incorporated into crop plants by using advanced biotechnological methods.

The bacterial spores can also be sprayed on the crops. They are ingested by insects and create pores in their gut wall which leads to their death. Thus Br-toxins work as biocontrol agent.

Question 11.
Why is Rhizobium categorised as a symbiotic bacterium? How does it act as a biofertiliser?
Answer:
Rhizobium lives in the root nodules of leguminous plants and fixes the atmospheric nitrogen by converting them into nitrogenous compounds.
These can be utilised by the plants as nutrients. Since, bacteria make the nitrogen available to plants in utilisable form, therefore, it is known as a biofertiliser.

Question 12.
How do plants benefit from having mycorrhizal symbiotic association?
Answer:

• The fungus absorbs phosphorus from the soil and passes it to the plant.
• Plants with mycorrhizal association show resistance to root borne pathogens.
• They show increased tolerance to salinity and drought.

Question 13.
Write short note on biofertiliser.
Answer:
Nutrients in optimum amount are important for the healthy growth, development and maximum productivity of plants.
Many nutrients required for the same include nitrogen and phosphorus which are the constituents of proteins, nucleic acids, coenzymes and some lipids like important biomolecules.
Phosphorus is present as insoluble phosphate in the soil sediments. On the other hand, nitrogen (80%) is present in atmosphere.

However, plants cannot use this atmospheric nitrogen and insoluble phosphates rather they either depend on microbes or chemical fertilisers to meet this basic necessity but, the continuous use of chemical fertilisers causes soil sickness, environmental pollution, etc. Thus, there is a pressure to shift to organic farming. Biofertilisers enrich the nutrient quality of soil by enhancing the availability of nutrients to the crops.

Differentiate between the following (for complete chapter)

Question 1.
Primary and Secondary sewage treatment.
Answer:
Differences between primary and secondary sewage treatment are as follows

Primary sewage treatment	Secondary sewage treatment
It is a physical process.	It is a biological process.
It involves the removal of grit and large pieces of organic matter.	It involves the digestion of organic matter by microbes.
It is carried out by the sedimentation and filtration process.	It is carried out by aerobic and anaerobic biological units.
It is relatively simple and less time consuming process.	It is relatively complex and takes a long time for its completion.

Question 2.
Primary sludge and Activated sludge.
Answer:
Differences between primary sludge and activated sludge are as follows

Primary sludge	Activated sludge
It is sludge formed during primary sewage treatment.	It is sludge formed during secondary sewage treatment.
It does not possess floes of decomposer microbes.	It possesses floes decomposer microbes.
It does not require aeration.	Formation of activated sludge requires aeration.
Little decomposition occurs during the formation of primary sludge.	A lot of decomposition occurs during the formation of activated sludge.

Question 3.
Swiss cheese and Roquefort cheese.
Answer:
Differences between Swiss cheese and Roquefort cheese are as follows

Swiss cheese	Roquefort cheese
They possess large holes.	They have relatively small holes.
These are made by Propionibacterium shermanii	These are ripened by Penicillium roquefort.

Question 4.
Methanogenic bacteria and Symbiotic bacteria.
Answer:
Differences between methanogenic bacteria and symbiotic bacteria are as follows

Methanogenic bacteria	Symbiotic bacteria
There bacteria are involved in energy production.	They are used as biofertilisers.
They live in the rumen of cattle.	They live in the root nodules of leguminous plants.
They produce methane gas by converting cellulose components into simple compounds, e.g. Methanobacterium.	They fix atmospheric nitrogen by converting it into nitrogenous compounds, e.g. Rhizobium.

Question 5.
Biopesticides and Biofertilisers.
Differences between biopesticides and biofertilisers are as follows

Biopesticides	Biofertilisers
They inhibit the growth of pests.	They help in the growth of crop plants.
They increase the yield by killing insects and pests, e.g, Bacillus thuringiensis.	They increase the yield by providing nutrients to the plants, e.g. Nostoc.

Long AnswerType Question

Question 1.
Discuss how waste water treatment can be done.
Answer:
Sewage refers to the municipal waste water generated everyday in cities and towns. Human excreta is the major component of it. It contains large amounts of organic matter and microbes, out of which many are pathogenic. So, it cannot be discharged directly into natural water bodies like rivers, streams, etc.

They need to be treated before their disposal. Conventional methods of waste treatment include cell pits, septic tanks, sewage farms, gravel beds percolating filters and activated sludge process with anaerobic digestion. These methods are less effective and sometimes non-productive.

The domestic sewage contains a large amount of degradable organic compounds. These can be degraded into simpler compounds with the help of microbes. The adequate supply of nutrients, oxygen and other essential compounds helps in the growth of microbes. It consequently enhances the rate of chemical degradation of sewage.

Therefore, modern method includes treatment of sewage before its disposal in local water bodies. Sewage is treated in Sewage Treatment Plants (STPs) in order to make it less polluting. The treatment of waste water is done by the heterotrophic microbes, that are naturally present in the sewage.

This treatment is carried out in the following three stages

Primary Treatment:
It is also known as physical treatment because it basically involves the physical removal of small and large, floating and suspended, non-biodegradable solids from sewage through filtration and sedimentation. Initially, floating debris is removed by sequential filtration. Then, the grit (soil and small pebbles) are removed by sedimentation process in settling tanks. Aluminium or iron sulphate is added in certain places for flocculation.

All solids that settle down during this step form the primary sludge. It traps lots of microbes and debris. The supernatant forms the effluent which is then taken from the primary settling tank for secondary treatment.

Secondary Treatment:
This treatment is also known as biological treatment because it involves the use of microbes or microbiota for the treatment of sewage. The effluent from primary treatment is passed into large aeration tanks, where it Is constantly, mechanically agitated and air is pumped into it.

This air helps in the growth of useful aerobic microbes” into floes (masses of bacteria associated with fungal filament to form mesh-like structures). While growing, these microbes consume major part of the organic matter, converting it into microbial biomass and releasing lot of minerals.
This significantly reduces the Biochemical Oxygen Demand (BOD) of water.

When the BOD of effluent is reduced significantly, it is then passed into a settling tank, where the bacterial ‘floes’ are allowed to sediment. This sediment is called activated sludge. A small part of the activated sludge is then pumped back into the aeration tank to serve as the inoculum. The remaining part of the sludge is pumped back into large tanks called anaerobic sludge digesters, in which other anaerobic bacteria (methanogens) are also present.

They digest the organic mass as well as aerobic microbes (bacteria and fungi of the sludge). During the digestion, mixture of gases like methane (CH₄), hydrogen sulphide (H₂S), carbon dioxide (CO₂), etc., are produced. These gases form biogas that is. used as a source of energy because it is inflammable.
The effluents from secondary treatment plant are released into natural water bodies like rivers and streams.

Tertiary Treatment:
It is an optional process including chemical precipitation. Its effectiveness depends on the number of microbes coming in contact with the pollutant organic molecules. Therefore, the secondary and tertiary treatments are performed in a constantly stirred open bioreactor that are supplied with nutrients.

Other Methods:
Sometimes a percolating or trickling fibre bioreactor is also used. In this method, a stone gravel or plastic sheet is used on which microbes have been immobilised. The sewage is allowed to flow on it. Deep shaft fermentation system is another method of waste water treatment.

This system contains a hole (deep shaft) in the ground. It is divided to allow the cycling and mixing of waste water, air and microbes. In some countries where sunlight hours are high, the algae-bacterial bioreactors are used. The biomass is used in the production of biogas and animal feed.

Odisha State Board CHSE Odisha Class 12 Biology Important Questions Chapter 10 Improvement in Food Production Important Questions and Answers.

CHSE Odisha 12th Class Biology Important Questions Chapter 10 Improvement in Food Production

Improvement in Food Production Class 12 Important Questions CHSE Odisha

Very Short Answer Type Questions

Choose the correct option

Question 1.
Inbreeding increases the frequency of
(a) recessive homozygotes
(b) dominant homozygotes
(c) heterozygotes
(d) Both (a) and (b)
Answer:
(d) Both (a) and (b)

Question 2.
Heterosis is
(a) hybrid inviability
(b) hybrid sterility
(c) hybrid vigour
(d) hybrid incompatibility
Answer:
(c) hybrid vigour

Question 3.
If you want to develop hybrid seeds within a bisexual flower which of the following parts need to be removed from the same flower?
(a) Stigma
(b) Ovary
(c) Anther
(d) Oviduct
Answer:
(c) Anther

Question 4.
Emasculation is one of the major steps during ………… .
(a) hybridisation
(b) pureline selection
(c) micropropagation
(d) crop improvement
Answer:
(a) hybridisation

Question 5.
Nutritional quality of crop plants like rice, maize, etc. is improved through ………… .
(a) biomagnification
(b) bioremediation
(c) biofortification
(d) bioaccumulation
Answer:
(c) biofortification

Question 6.
The capacity of a plant cell to give rise to a new plant is called …………. .
(a) cotipotency
(b) reproduction
(c) budding
(d) regeneration
Answer:
(a) totipotency

Question 7.
Single Cell Protein (SCP) is
(a) protein obtained from a clone of cells
(b) protein obtained from unicellular organisms
(c) biomass obtained from microorganisms
(d) proteins obtained from biomass of microorganisms
Answer:
(c) biomass obtained from microorganisms

Question 8.
Somatic hybridisation can be used for
(a) gene transfer
(b) transfer of cytoplasm
(c) formation of allopolyploids
(d) All of the above
Answer:
(d) All of the above

Question 9.
The emasculation is required for
(a) purelines
(b) cross pollination
(c) natural hybridisation
(d) selective hybridisation
Answer:
(d) selective hybridisation

Question 10.
An example of improved wheat
(a) Jaya
(b) Pusa Swarnim
(c) Sonalika
(d) Pusa Shubra
Answer:
(c) Sonalika

Question 11.
The organic nutrient of a plant tissue culture medium are
(a) sucrose
(b) glucose
(c) fructose
(d) All of these
Answer:
(d) All of these

Question 12.
Embryo like structure produced in vitro culture is called
(a) embryoid
(b) zygote
(c) somatic hybrid
(d) cybrid
Answer:
(a) embryoid

Question 13.
Which one of the following statement regarding pomato is correct ?
(a) It is a product of somatic hybridisation
(b) It is a product of gene manipulation
(c) product of sexual hybridisation
(d) product of cloning
Answer:
(a) It is a product of somatic hybridisation

Question 14.
An indigenous breed of cattle developed through cross breeding is
(a) Red Dane
(b) Karan Swiss
(c) Jersey (d) Rathi
Ans.
(b) Karan Swiss

Question 15.
The cross-breed of cattle is
(a) Ongole
(b) Sunandini
(c) Tharparkar
(d) Kangayam
Ans.
(b) Sunandini

Question 16.
In India, the milk yield of cattle is low due to
(a) inferior breeds
(b) inadequate food
(c) Both (a) and (b)
(d) use of medicines
Answer:
(c) Both (a) and (b)

Question 17.
Which of the following is a disease of cattle?
(a) Ranikhet disease
(b) Coryza
(c) Marek’s disease
(d) All of these
Answer:
(d) All of these

Question 18.
Fowlpox is caused by
(a) ectoparasites
(b) endoparasites
(c) bacteria
(d) virus
Answer:
(d) virus

Question 19.
Which of the following species of bee is commercially cultivated?
(a) Apis dorsata
(b) Apis mellifera
(c) Apis florea
(d) Apis indica
Answer:
(b) Apis mellifera

Question 20.
Which of the following species of honeybee is reared in artificial hives?
(a) Apis indica
(b) Apis dorsata
(c) Apis florea
(d) None of these
Answer:
(a) Apis indica

Question 21.
The term used for birds raised under domesticaton for economic purpose is called
(a) fisheries
(b) poultry
(c) apiculture
(d) aquaculture
Answer:
(b) poultry

Question 22.
Which of the following breed of buffalo has maximum milk fat percentage in its milk?
(a) Nagpuri
(b) Bhadawari
(c) Mehsana
(d) Murrah
Answer:
(d) Murrah

Question 23.
High milk yielding varieties of cows are obtained by
(a) superovulation
(b) artificial insemination
(c) use of surrogate mothers
(d) All of the above
Answer:
(d) All of the above

Question 24.
Artificial insemination is better than natural insemination in cattle because
(a) semen of good bulls can be provided everywhere
(b) there is no likelihood of contagious diseases
(c) it is economical
(d) All of the above
Answer:
(a) semen of good bulls can be provided everywhere

Question 25.
Which of the following about breeding is incorrect?
(a) By inbreeding purelines cannot be evolved
(b) Continued inbreeding, especially closed inbreeding reduces fertility and productivity
(c) Cross breeding allows desirable qualities of different breeds to be confined
(d) Inbreeding exposes harmful recessive genes that are eliminated by selection
Answer:
(a) By inbreeding purelines cannot be evolved

Question 26.
Which one of the following methods of selection is mainly useful for cross pollinated crops?
(a) Mass selection
(b) Pureline selection
(c) Progeny selection
(d) Clonal selection
Answer:
(b) Pureline selection

Question 27.
Which one of the following breeds of buffaloes is in most demand?
(a) Surti
(b) Jaffrabadi
(c) Murrah
(d) Bhadawari
Answer:
(c) Murrah

Question 28.
Heterosis cannot be maintained in sexually reproducing plants as it disappears on
(a) outbreeding
(b) inbreeding
(c) cross-breeding
(d) None of these
Answer:
(c) cross-breeding

Question 29.
Bagging is done to
(a) achieve desired pollination
(b) prevent contamination of unwanted pollen
(c) avoid self-pollination
(d) avoid cross-pollination
Answer:
(b) prevent contamination of unwanted pollen

Question 30.
A nutritional disease, which is found in poultry birds is
(a) rickets
(b) Ranikhet
(c) fowl cholera
(d) aspergillosis
Answer:
(a) rickets

Question 31.
In honeybees, the drones develop from
(a) fertilised egg
(b) unfertilised egg
(c) schizogony
(d) asexual reproduction
Answer:
(a) fertilised egg

Correct the statements, if required, by changing the underlined word(s)

Question 1.
The genetically superior individuals are called clones.
Answer:
hybrids

Question 2.
Selection is mixing out plants with desirable characters in a population.
Answer:
sorting out

Question 3.
Hybridisation is a cross between genetically similar organisms.
Answer:
genetically dissimilar

Question 4.
Hybridisation is one of the best methods adopted for crop improvement.
Answer:
Correct, no change

Question 5.
An amorphous mass of parenchyma cells developed by tissue culture is called embryo.
Or
In tissue culture, amorphous mass of thin-walled parenchymatous cells developing from proliferating cells is called explant.
Answer:
Callus

Question 6.
Naked plant cell without cell wall is called plasmalemma.
Answer:
Protoplast

Question 7.
Tissue culture technique was first attempted by Hanning.
Answer:
Haberlandt

Question 8.
Mutational variations are the ones produced during tissue culture.
Answer:
Somaclonal

Question 9.
NDRI is situated in Lucknow.
Answer:
Karnal

Question 10.
The giant honeybee, yielding maximum honey is Apis mellifera.
Answer:
Apis dorsata

Question 11.
In honeybee, the process of development of male bee without fertilisation is termed as swarming.
Answer:
Parthenogenesis

Question 12.
The branch of agriculture which deals with feeding shelter, health and breeding of domestic animals is called animal husbandry.
Answer:
It is correct

Question 13.
Animal food is generally rich in micronutrients.
Answer:
vitamins and roughage

Question 14.
Removal of stamens before release of pollen grains from the plants is called anthesis.
Answer:
emasculation

Question 15.
Mass selection is the simplest method of plant breeding applied mainly in case of self-pollinated crops.
Answer:
cross-pollinated

Express in one or two word(s)

Question 1.
Name the hormones used in tissue culture.
Answer:
2,4-D(auxin) and cytokinin

Question 2.
What is the use of polyethylene glycol in somatic hybridisation?
Answer:
Promotes protoplast fusion

Question 3.
Name an alga used as single cell protein.
Answer:
Chlorella

Question 4.
Which organs are develop during organogenesis?
Answer:
Root and shoot

Question 5.
The birds reared for meat purpose.
Answer:
Broilers.

Question 6.
Breeding between unrelated individuals.
Answer:
Outbreeding.

Question 7.
The important monosaccharide present in – honey.
Answer:
Levulose.

Question 8.
Name the strategy used to increase the homozygosity in cattles for desired traits.
Answer:
Inbreeding

Question 9.
Name an exotic breed of cow.
Answer:
Jersey

Question 10.
List any two economically important products for human obtained from Apis indica.
Answer:
Honey and beeswax

Question 11.
Name any two poultry diseases.
Answer:
Fowl pox and Ranikhet disease

Fill in the blanks

Question 1.
During hybridisation, emasculated buds need to be ……….. .
Answer:
bagged

Question 2.
Technique for production of disease-free plants is …………… .
Answer:
tissue culture

Question 3.
Crosses between the plants of the same variety are called ………. .
Answer:
inter-varietal

Question 4.
The most convenient way of removal of stamens is ……… .
Answer:
emasculation

Question 5.
Continued close inbreeding reduces fertility and productivity which is called ……….. .
Answer:
inbreeding depression

Question 6.
Milk yielding cattle breeds are known as ………. breeds.
Answer:
milch

Question 7.
Exotic breed of poultry bird is ……….. .
Ans. playmouth rock

Question 8.
The juvenile bees are reared in ……….. chamber of the honeycomb.
Answer:
brood

Question 9.
In bees, dance is meant for ………… .
Answer:
direction and distance

Question 10.
The loss of vigour due to continuous inbreeding is known as …………… .
Answer:
inbreding depression

Question 11.
The characteristic flight of the queen bee during fertilisation is known as ……………… .
Answer:
nuptial flight

Question 12.
Culturing of honeybee on commercial basis is known as …………. .
Answer:
apiculture

Short Answer Type Questions

Question 1.
Write note on hybridisation with 2-3 important points.
Answer:
It is possible by cross hybridising the two parents to produce hybrids that genetically combine the desired characters in a single plant. It is known to be a time consuming and tedious process as it involves collection of pollen grains from the desired plants (male parent) and have to be placed on the stigma of the selected flower (female parent) to incorporate desired traits.

It is also not necessary that the hybrids do combine desired characters. The chances of desirable combination is usually only one in few hundred to a thousand crosses carried out.

Some of the objectives of hybridisation are as follows

• To produce variations in progeny which are useful.
  It is achieved by recombination of characters.
• To make the use of hybrid vigour which is the superiority of progeny over its parents.
• To develop high yielding varieties which are also resistant to diseases.

Question 2.
Write a short note on emasculation.
Answer:
Emasculation It is the process of removal of stamens of a flower, without affecting the female reproductive organs. Emasculation is usually done in bisexual flowers before the anthers mature and stigma has become receptive. It can be done by various methods, such as, hand emasculation, suction method, hot water emasculation, alcohol treatment, cold treatment and genetic emasculation. Among these methods, hand and suction method are mostly used.

For example, in Triticum (wheat) flowers may be exposed to some chemical like 2,4-dichloro phenoxyacetic acid, maleic hydrozide or a panicle of Sorghum is dipped in lukewarm (50°C) water for 10 minutes, etc. These methods are applied on those cases where the methods of physical nature could not be applied.

Question 3.
(i) Mention two ways of inducing artificial mutation in a crop field.
(ii) List two steps that help in introducing the desired mutation into the crop.
Answer:
(i) Artificial mutation can be induced in a crop field by

• Using chemicals (like aniline).
• Radiations (like gamma-radiations).

(ii) Two steps that help in introducing the desired mutation into the crops are

• Screening the plant for resistance.
• Selecting the desirable plants for multiplication and for breeding.

Question 4.
How has mutation breeding helped in improving the production of mung bean crop?
Answer:
Mutation breeding is a phenomenon by which genetic variation is achieved through changes in base sequences within genes.
This creates a new character or trait absent in parental generation. It is the process of breeding by artificially inducing mutations using chemicals or radiations, e.g. in moong bean, resistance to yellow mosaic virus and powdery mildew were introduced by this method.

Question 5.
Discuss the importance of testing of new plant varieties in a geographically vast country like India.
Answer:
Before the new plants are generated through the plant breeding programmes, they need to be evaluated for their yield and other agronomic traits of quality, disease resistance, etc. The testing is done on the farmer’s field for atleast three growing seasons, at different locations in the country representing all the agroclimatic zones, where the crop is usually grown.

The material is evaluated in comparison to the best available local crop cultivar known as a check or reference cultivator.

Question 6.
What is meant by biofortification? Explain.
Answer:
It is a method of breeding crops with higher levels of vitamins, minerals, healthier fats to improve public health. The objective of breeding for improved nutritional quality is to enhance

• Protein, oil content and quality.
• Vitamin content.
• Micronutrients and mineral content.

Question 7.
Why are biofortified maize and wheat considered nutritionally improved?
Answer:
Biofortified maize and wheat are considered nutritionally improved, because of following reasons

• Maize hybrids have twice the amount of amino acid, lysine and tryptophan as compared to existing maize hybrids.
• Atlas-66 has been used as a donor for developing wheat varieties with improved protein content.

Question 8.
Enumerate four objectives for improving the nutritional quality of different crops for the health benefits of the human population by the process of ‘biofortification’.
Answer:
Four objectives for improving nutritional quality of crops

• Protein content and quality.
• Oil content and quality.
• Vitamin content.
• Micronutrient and mineral content.

Question 9.
Write a note on single cell protein.
Answer:
Microbial biomass passess about 45-55% protein, but in certain bacteria, the protein content may be upto almost 80%. The term ‘single cell protein’ refers to microbial biomass which acts as a source of mixed proteins. They are extracted from pure or mixed culture of organisms or cells.

SCP act as a supplement or alternative source of protein that is not supplied by the traditional or conventional agriculture production. Mirobes are being grown commercially as a sources of SCP. They are

• Yeast Saccharomyces cerevisiae
• Filamentous fungi Eusarum graminearum
• Bacteria Methylophilus methybtrophus
• Cyanobacteria Spirulina
• Algae Chlorella

Question 10.
How can healthy potato plants be obtained from a desired potato variety which is viral infected? Explain.
Answer:
Healthy potato plants can be obtained from a desired potato variety which is viral infected with the help of tissue culture.
The apical and axillary meristems of the infected plant remain virus free. Hence, they are removed and grown in vitro to obtain healthy potato plants. This is one of the application of tissue culture.

Question 11.
Write a note on micropropagation with 2-3 important points.
Answer:
Micropropagation or Clonal Propagation:
By the process of plant tissue culture which requires lesser space and lesser time, a large population of plants could be raised. Also since the plants produced are genetically identical, this process is also called as clonal propagation. Examples of plants cutlivated micropropagation include grapes, bamboo, coffee, banana, cardamoms, etc.

Question 12.
(i) Why are the plants raised through micropropagation termed as somaclones?
(ii) Mention two advantages of this technique.
Answer:
(i) The plants produced by micropropagation are genetically identical to the original plant from which they are grown, so they are called somaclones.

(ii) Advantages of this technique are

• More number of plants can be produced in a short time
• Disease free plants can be developed from diseased plants. Also seedless plants can be multiplied.

Question 13.
Why are plants obtained by protoplast culture called somatic hybrids?
Answer:
Plants obtained by protoplast culture are called somatic hybrids because they are formed by the fusion of isolated protoplasts from two different varieties of plants, each having a desirable character, to obtain a hybrid protoplast which can be further grown to form a plant.

Question 14.
Name the steps represented in the following process.

Answer:
A – Collection of germplasm.
B – Cross hybridisation among selected plants.
C – Selection and testing of superior recombinants.

Question 15.
Explain in brief the role of animal husbandry in human welfare.
Answer:
Domesticated animals of any breed or population of animal, which are intentionally kept in an agricultural setting for the benefit of human beings are referred to as ‘lifestock’. The agricultural practice of breeding and raising livestock is called animal husbandry.

It deals with care and breeding of animals like buffaloes, cows, pigs, horses, cattle, sheep, camels, goats, etc. by humans for various products like milk, meat, wool, etc. Poultry farming and fisheries are also considered as the

part of animal husbandry. According to a survey, about 70% of world’s livestock population is in India and China. Despite this huge production, their contribution to the world farm produce is only 25%, i.e the productivity per unit is very low.

Question 16.
What is meant by the term breed? What are the objectives of animal breeding?
Answer:
A breed is a group of animals related by descent and similar in most character like general appearance, features, size configuration, etc. Red Dane, Jersey, Brown Swiss are the examples of foreign breeds of cow.

Objectives of animal breeding are

• To increase the yield of animals.
• To produce disease resistant varieties of animals.
• To improve the desirable qualities of the animal produce such as milk, etc., having high protein content, etc.

Question 17.
What is the difference between breed and species? Give an example for each category.
Answer:
Breed is a specific group of animals or plants having homogeneous appearance, behaviour and other characteristics that distinguishes it from other animals or plants of the same species, e.g. Red Dane, Jersey, Brown Swiss are some common breeds of cow.

Species is one of the basic units of biological classification and a taxonomic rank. It can be defined as the largest group of organisms capable of interbreeding and producing fertile offspring, e.g. lion, cow, dog.

Question 18.
Enumerate any six essentials of good, effective ‘dairy farm management practices?
Answer:
Dairying is the management of animals for milk and its products for human consumption. Dairy farming integrated with agricultural farming has been the base of Indian economy since long time. It mainly deals with the processes and systems to improve quality and quantity of milk. Milk yield mainly depends on the quality of breeds. The dairy farm management includes the following main processes

1. Selection of good breeds with high yielding potential (under the climatic conditions of the area) and resistance to various diseases.
2. Cattle should be housed-well, have sufficient water and should be kept in diseased-free conditions.
3. They should be fed in a scientific manner with an emphasis on quality and quantity of fodder.
4. Regular inspection and keeping proper records of all the activities of dairy is also important.
5. Regular visits of a veterinary doctor is necessary.
6. Stringent cleanliness and hygiene of both the cattle and the handler are very important during milking, storage and transport of milk and its products.

Question 19.
Enlist the steps involved in inbreeding of cattle. Suggest two disadvantages of this practice.
Answer:
The mating of closely related animals within the same breed for 4-6 generations is called inbreeding. The strategies for inbreeding are

1. Superior males and females of the same breed are identified and then mated.
2. The progeny obtained from such type of matings are evaluated and superior males and females among them are identified for further mating.
3. In case of cattle, more milk per lactation is the criteria for superior female for cow and buffalo. Whereas a superior male is the one who give rise to superior progeny.

When the inbreeding is repeated it is called upgrading. Inbreeding is advantageous in the introduction of beneficial genes without changing the original genetic composition. But, inbreeding has disadvantages also. Inbreeding may lead to the expression of harmful effects of the deleterious gene. This results in inbreeding depression as it brings harmful recessive genes together. It cause decrease fertility and hybrid vigour of, in cattle.

Question 20.
State the disadvantage of inbreeding among cattle. How it can be overcome?
Or
How does inbreeding depression set in? Mention the procedure you would suggest to reverse this.
Answer:
Inbreeding depression usually reduces fertility and even productivity. It sets in due to continued inbreeding especially close inbreeding.
When inbreeding depression takes place or happens, selected animals of the breeding population should be mated with the unrelated superior animals of the same breed. This will help to restore the fertility and yield.

Question 21.
Why interspecific crosses are rare in nature and intergeneric crosses almost unknown?
Answer:
In interspecific crosses, male and female animals of two different related species are mated. The resultant progeny may combine desirable features of both the parents are infertile. Thus are rare in nature.
The same applies to intergeneric crosses. It is the crossing of two different animals/plants of different genus. It is almost unknown in nature as the gametes show species specificity.

Question 22.
What is artificial insemination? Mention two ways in which it is useful in breeding of dairy animals.
Answer:
Artificial insemination is a method of improvement in animals by using controlled breeding methods. During this process, the semen collected from the selected superior quality male parent is injected into the reproductive tract of selected female parent by the breeder. Breeding of dairy animals by the artificial insemination methods is useful in following two main ways

1. The bull of superior quality can be made to inseminate with many cows so, as to produce a large number of offsprings with desired trait.
2. The offsprings produced by artificial insemination have higher yield as compared to the normal offspring.

Question 23.
What is meant by transgenic animals?
Answer:
Refer to text on page no. 280.

Question 24.
What is the utility of transgenic animals?
Answer:
Transgenic animals are used to obtain various products like CC-antitrypsin, haemoglobin, iron binding protein, lacteferrin, etc. In Japan, gynogenesis is being used to improve fish size.

Question 25.
What is apiculture? How is it important in our lives?
Answer:
Refer to text on page no. 280.

Question 26.
Briefly describe swarming in honeybees.
Answer:
During early summer, when the beehive becomes loaded with honey and overcrowded by bees, the queen leave the hive with some drones and workers to establish a new colony at some other new place. This process is called as swarming.

Question 27.
Why are beehives kept in a crop field during flowering period ? Name any two crop fields where this is practised.
Answer:
Bees, while collecting nectar from flowers, transfer the pollen grains. Beehives are kept in a crop field during flowering period to enhance the pollination of the crop, which increases the crop yield. Also, bees can easily collect huge amounts of nectar from .the flowers of the crop in a close reach without much foraging.
This in turn increases the production of honey, e.g. this technique is practised in apple and mustard fields.

Question 28.
Social life of honeybees.
Or
Write a note on queen bee.
Answer:
Honeybees are social and polymorphic insects. They are of three main types

1. Queen It is fertile female. It is diploid as it develops from a fertilised egg. It feeds on royal jelly. It has well-developed ovary for laying eggs.
2. Drone It is a fertile male. It is haploid as it develops from unfertilised egg by the process of parthenogenesis. It copulates with queen.
3. Worker It is a sterile female. It is diploid. They are workers of beehives.

Worker bees have some specific structure such as long proboscis to collect nectar pollen basket to collect pollen, wax secreting glands in abdomen to secrete wax and powerful sting for defence.

Question 29.
What is beeswax?
Answer:
Beeswax is a secretory product of hypodermal glands of workers bees abdomen. It is used in the industries for the manufacture of cosmetics, polishes, paints ointments and lubricants.

Differentiate between the following (for complete chapter)

Question 1.
Hybrids and Cybrids.
Answer:
Differences between hybrids and cybrids are as follows

Hybrids	Cybrids
When nuclear and cytoplasmic fusion occur, the product is known as hybrid.	When only cytoplasmic fusion occurs which may be followed by the loss of any one of the nucleus, it is known as cybrid.

Question 2.
Inbreeding and Outbreeding.
Answer:
Differences between inbreeding and outbreeding are as follows

Inbreeding	Outbreeding
Mating of closely related animals of the same breed is called inbreeding.	Mating of unrelated animals belonging to different breeds or different species is called outbreeding.
It Increases homozygosity by which the prepotency of inbreed line increases.	It increases heterozygosity which results in hybrid vigour.
It reduces genetic variance within lines.	It increases genetic variance within lines.

Question 3.
Explant and Callus.
Answer:
Differences between explant and callus are as follows

Explant	Callus
These are small pieces of plant part of tissues that are aseptically cut and used to propagate a plant in vitro.	It is an unorganised and undifferentiated mass of proliferative cells produced when explants are grown on artificial culture medium in vitro.
Explants are readily available from parent plants.	Callus is obtained from culturing of explant within 2-3 weeks.

Question 4.
Callus culture and Suspension culture.
Answer:
Differences between callus culture and suspension culture are as follows

Callus culture	Suspension culture
In this culture, cell division in explant forms a callus. Callus is an irregular unorganised and undifferentiated mass of actively dividing cells.	It consists of single cells and small groups of cells suspended in a liquid medium.
The culture is maintained in agar medium	The culture is maintained in liquid medium
The medium contains growth regulators the auxin such as 2,4-D and cytokinin like BAP.	The medium contains growth regulator auxin such as 2, 4-D only.
Callus is obtained within 2-3 weeks.	Suspension cultrue grow much’faster than callus culture.
It does not need to be agitated.	It must be constantly agitated at 100-250 rpm (revolutions per minute).

Question 5.
Somatic embryogenesis and Somatic hybridisation.
Answer:
Differences between somatic embryogenesis and somatic hybridisation are as follows

Somatic Embryogenesis	Somatic hybridisation
A Somatic Embryo (SE) is an embryo derived from a somatic cell, other than zygote.	Somatic hybrids are formed through the fusion of protoplasts of two plants belonging to different varieties, species and even genera.
Somatic embryos are obtained usually on culture of the somatic cells in vitro, this process is called somatic embryogenesis	The process through which somatic hybrids are formed is known as somatic hybridisation
It is induced by a relatively high concentration of auxin, like 2, 4-D.	The fused protoplasts are either cultured in liquid or semi-liquid agar medium plates.

Question 6.
Broilers and Layers.
Answer:
Differences between broilers and layers are as follows

Broilers	Layers
These are comprised of both male and females.	These are females only.
Broilers are reared for meat production.	Layers are reared for egg production.
These attain a body weight of 2.2-2.4 kg within 6 weeks, this is due to faster growth.	Layers attain a body weight of approximately 1.5-1.8 kg at sexual maturity (20-2 weeks).