Sure Shot Questions

Chapter – 01
Sexual Reproduction in Flowering Plants
 MCQ (c) microspore tetrads
(d) pollen grains.
1. Embryo sac is to ovule as _______ is to an anther.
7. From among the sets of terms given below, identify
(a) stamen (b) filament
those that are associated with the gynoecium.
(c) pollen grain (d) androecium
(a) Stigma, ovule, embryo sac, placenta
(b) Thalamus, pistil, style, ovule
(c) Ovule, ovary, embryo sac, tapetum
2. In a typical complete, bisexual and hypogynous
(d) Ovule, stamen, ovary, embryo sac
flower the arrangement of floral whorls on the
thalamus from the outermost to the innermost is
8. From the statements given below, choose the
(a) calyx, corolla, androecium and gynoecium
option that are true for a typical female
(b) calyx, corolla, gynoecium and androecium
gametophyte of a flowering plant.
(c) gynoecium, androecium, corolla and calyx
(i) It is 8-nucleate and 7-celled at maturity,
(d) androecium, gynoecium, corolla and calyx.
(ii) It is free-nuclear during the development,
(iii) It is situated inside the integument but outside
the nucellus. It has an egg apparatus situated at
3. A dicotyledonous plant bears flowers but never
the chalazal end.
produces fruits and seeds. The most probable cause
(a) (i) and (iv) (b) (ii) and (iii)
for the above situation is
(c) (i) and (ii) (d) (ii) and (iv)
(a) plant is dioecious and bears only pistillate
flowers
9. Choose the correct statement from the following,
(b) plant is dioecious and bears both pistillate and
(a) Cleistogamous flowers always exhibit autogamy,
staminate flowers
(b) Chasmogamous flowers always exhibit
(c) plant is monoecious
geitonogamy.
(d) plant is dioecious and bears only staminate
(c) Cleistogamous flowers exhibit both autogamy
flowers.
and geitonogamy.
(d) Chasmogamous flowers never exhibit autogamy.
4. Pollen grains are well preserved as fossils because
of presence of
10. A particular species of plant produces light, non-
sticky pollen in large numbers anad its stigmas are
(a) sporopollenin (b) cellulose
long and feathery. These modifications facilitate
(c) lignocellulose (d) pectocellulose.
pollination by
(a) insects (b) water
5. The outermost and innermost wall layers of
(c) wind (d) animals.
microsporangium in an anther are respectively
(a) endothecium and tapetum
11. In the figure of anatropous ovule given below,
(b) epidermis and endodermis
choose the correct option for the characteristic
(c) epidermis and middle layer
distribution of cells within the typical embryo sac.
(d) epidermis and tapetum.

6. During microsporogenesis, meiosis occurs in

(a) endothecium
(b) microspore mother cells

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 Numbe Number Numbe 17. The phenomenon observed in some plants wherein
r of of cells at r of parts of the sexual apparatus is used for forming
cells at micropyla nuclei embryos without fertilisation is called
chalaza r end left in
l end central (a) parthenocarpy
cell (b) apomixis
(a 3 2 3 (c) vegetative propagation
) (d) sexual reproduction.
(b 3 3 2
) 18. In a flower, if the megaspore mother cell forms
(c) 2 3 3 megaspores without undergoing meiosis and if one
(d 2 2 4 of the megaspores develops into an embryo sac, its
) nuclei would be

12. From among the situations given below, choose the (a) haploid
one that prevents both autogamy and (b) diploid
geitonogamy. (c) a few haploid and a few diploid
(a) Monoecious plant bearing unisexual flowers, (d) with varying ploidy.
(b) Dioecious plant bearing only male or female
flowers, 19. A group of compactly arranged homogeneous mass
(c) Monoecious plant with bisexual flowers, of cells occupying the centre of a typical
(d) Dioecious plant with bisexual flowers. microsporangium in an anther is

13. In a fertilised embryo sac, the haploid, diploid and (a) Sporogenous tissue
triploid structures are (b) Pollen sacs
(a) synergid, zygote and primary endosperm (c) Microspore tetrads
nucleus (d) Spores.
(b) synergid, antipodal and polar nuclei
(c) antipodal, synergid and primary endosperm 20. The figures of the developmental stage of a
nucleus microspore into a mature pollen grain are given
(d) synergid, polar nuclei and zygote. below. Choose the option showing the correct
labellings for (i), (ii), (iii) and (iv).
14. In an embryo sac, the cells that degenerate after [Term-I, 2021 – 22]
fertilisation are

(a) synergids and primary endosperm cell

(b) synergids and antipodals
(c) antipodals and primary endosperm cell
(d) egg and antipodals.

15. The structure of bilobed anther consists of

(a) 2 thecae, 2 sporangia
(b) 4 thecae, 4 sporangia
(c) 4 thecae, 2 sporangia
(d) 2 thecae, 4 sporangia.

16. In the embryos of a typical dicot and a grass, true

homologous structures are

(a) Coleorhiza and coleoptile

(b) Coleoptile and scutellum
(c) Cotyledons and scutellum
(d) Hypocotyl and radicle.
 Assertion & Reason

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21. Assertion (A) : Apomictic embryos are genetically very well preserved for thousands of years in soil
identical to the parent plant. and sediments.
Reason (R) : Apomixis is the production of seeds
without fertilisation, (a) What is the key advantage to the plant for
having such strong pollen grain walls?
(a) Both (A) and (R) are true and (R) is the correct
explanation of (A), a) It allows pollen to serve as a valuable fossil
(b) Both (A) and (R) are true and (R) is not the record for the study of ancient plants.
correct explanation of (A), b) It prevents the pollen tube from growing out
(c) (A) is true but (R) is false, before the pollen grain reaches the stigma of a
(d) (A) is false but (R) is true. [2022 – 23] compatible species.
c) It protects the vital genetic material in the pollen
22. Assertion: A typical dicotyledonous embryo consists grain.
of an embryonal axis and two cotyledons. d) It gives weight to the pollen grain, allowing it to
Reason: Embryos of monocotyledons possess only cling better to the body surfaces of insect
one cotyledon. pollinators.
(b) The number of germ pores in dicots and
23. Assertion: Pollen grain of angiosperm is considered monocots respectively are
as a male gametophyte.
Reason: Pollen grain consists of stigma, style, and a) Three and one b) Two and three
ovary. c) Three and two d) One and three

24. Assertion: Megaspore mother cell undergoes (c) One of the most resistant biological material
meiosis to produce four megaspores. present in the exine of pollen grain is
Reason: Megaspore mother cell and megaspore
both are haploid. a) Pectocellulose b) Sporopollenin
c) Suberin d) Cellulose.
25. Assertion: In a microsporangium, the tapetal cells
possess little cytoplasm and generally have a single (d) The exine possesses one or more thin places
prominent nucleus. known as
Reason: During microsporogenesis, the microspore
mother cells undergo mitotic divisions to produce a) Endothecium. b) Hilum
haploid microspore tetrads. c) Germ pores d) Raphe

26. Assertion: In angiosperms, endosperm (e) What is the function of germ pore?
development precedes embryo development. i. Emergence of radicle
Reason: This occurs to ensure to provide nutrition ii. Absorption of water for seed germination
to the developing embryo. iii. Initiation of pollen tube
iv. All of these
27. Assertion: Pollination by bats is known as
chiropterophily. a) Option (d) b) Option (b)
Reason: Pollination by birds is known as c) Option (a) d) Option (c)
ornithophily.
29. Read the text carefully and answer the questions:
 Case Study The pollen grains or microspores are the male
reproductive bodies of a flower and are contained
28. Read the text carefully and answer the questions: in the pollen sac or microsporangia. Each pollen
The pollen grains or microspores are the male grain consists of a single microscopic cell,
reproductive bodies of a flower and are contained possessing two coats: the exine and the intine. The
in the pollen sac or microsporangia. Each pollen exine of a pollen grain is made of chemically stable
grain consists of a single microscopic cell, material. Because of this, pollen grains are often
possessing two coats: the exine and the intine. The very well preserved for thousands of years in soil
exine of a pollen grain is made of chemically stable and sediments.
material. Because of this, pollen grains are often

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 (a) What is the key advantage to the plant for 33. Mention the reasons for difference in ploidy of a
having such strong pollen grain walls? zygote and a primary endosperm nucleus in an
angiosperm.
a) It allows pollen to serve as a valuable fossil
record for the study of ancient plants. 34. Hybrid seeds have to be produced year after year.
b) It prevents the pollen tube from growing out Explain.
before the pollen grain reaches the stigma of a
compatible species. 35. Draw a schematic transverse section of a mature
c) It protects the vital genetic material in the pollen anther of an angiosperm. Label its epidermis,
grain. middle layers, tapetum, endothecium, sporogenous
d) It gives weight to the pollen grain, allowing it to tissue and the connective.
cling better to the body surfaces of insect
pollinators. 36. Double fertilisation is reported in the plants of both,
castor and groundnut. However the mature seeds
(b) The number of germ pores in dicots and of groundnut are non-albuminous and castor are
monocots respectively are albuminous.
Explain the post fertilisation events that are
a) Three and one b) Two and three responsible for it.
c) Three and two d) One and three

(c) One of the most resistant biological material 37. With the help of neat well labelled diagram, explain
present in the exine of pollen grain is in short about a typical anatropous ovule.
Or
a) Pectocellulose b) Sporopollenin With a neat, labelled diagram, describe the parts of
c) Suberin d) Cellulose. typical angiospermic ovule.
Or
(d) The exine possesses one or more thin places Draw a well labelled diagram of a typical
known as anatropous ovule.

a) Endothecium. b) Hilum
c) Germ pores d) Raphe 38. Draw a neat labelled sketch of L.S of an
endospermous monocot seed.
(e) What is the function of germ pore?

i. Emergence of radicle 39. (a) Draw a L.S. of pistil showing pollen tube entering
ii. Absorption of water for seed germination into the embryo sac. Label the following:
iii. Initiation of pollen tube (i) Nucellus
iv. All of these (ii) Antipodals
(iii) Ssynergids
a) Option (d) b) Option (b) (iv) Micropyle
c) Option (a) d) Option (c)
(b) Write the functions of the following:
 Questions (i) Synergids (ii) Micropyle
30. Name the organic materials exine and intine of an
angiosperm pollen grain are made up of. Explain 40. Draw a labelled figure of an embryo of a grass.
the role of exine? Or
Draw L.S of an embryo of grass
31. Name the organic materials exine and intine of an
angiosperm pollen grain are made up of. Explain 41. Differentiate between Microsporogenesis and
the role of exine. Megasporogenesis. What type of cell division
occurs during these events? Name the structure
32. Draw a diagram of a matured microspore of an formed at the end of these two events.
angiosperm. Label its cellular components only.
42. Provide differences between Epicotyls and
Hypocotyls.
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 55. (i) Double fertilisation is an event unique to all
43. Differentiate between Integument and Testa. flowering plants. Explain the process,
(ii) Give a reason for the following:
44. Differentiate between Perisperm and Pericarp. (1) A seed of an orange has many embryos.
(2) Cashew is a false fruit but guava is a true fruit.
45. Differentiate between Perisperm and Endosperm
giving one example each 56. (a) Where does microsporogenesis occur in an
angiosperm? Describe the process of
46. Why does endosperm development precede microsporogenesis.
embryo development? (b) Draw a labeled diagram of the two celled male
gametophyte of an angiosperm. How is a three
47. Trace the development of a megaspore mother cell celled male gametophyte different from it? [2020]
to the formation of mature embryo sac in a flower
plant
57.
48. How many meiotic divisions are required to
produce 76 seeds in a guava fruit?

49. Mention the function of coleorhiza. [Delhi 2015C]

50. Differentiate between parthenogenesis and

parthenocarpy.

51. Mention advantages of apomictic seeds to farmers.

52. (a) How is apomixes different from parthenocarpy? These picture show the gynoecium of (A) Papaver
(b) Describe any two modes by which apomictic and (B) Michelia flowers. Write the difference in the
seeds can be produced. structure of their ovaries.

53. (a) Draw a labeled diagram of the sectional view of 58. State the function of filiform apparatus found in
microsporangium of an angiosperm. mature embryo sac of an angiosperm. [Foreign
(b) Explain the development of male gametophyte 2014]
in the microsporangium.
59. Where are the following structures present in a
54. (i) Explain the monosporic development of embryo male gametophyte of an angiosperm? Mention the
sac in the ovule of an angiosperm. function of each one of them.
(ii) Draw a diagram of the mature embryo sac of an (a) Germ pore
angiospermic ovule and label any four parts of it. (b) Sporopollenin
(c) Generative cell

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 Sure Shot Questions
Chapter – 02
Human Reproduction
 MCQ
6. Which one of the following is not a male accessory
gland?
1. Choose the incorrect statement from the
(a) Seminal vesicle
following,
(b) Ampulla
(a) In birds and mammals internal fertilisation
(c) Prostate
takes place,
(d) Bulbourethral gland
(b) Colostrum contains antibodies and nutrients,
(c) Polyspermy in mammals is prevented by the
7. The immature male germ cells undergo division to
chemical changes in the egg surface,
produce sperms by the process of
(d) In the human female, implantation occurs
spermatogenesis.
almost seven days after fertilisation.
Choose the correct one with reference to above,
(a) Spermatogonia have 46 chromosomes and
2. Identify the correct statement from the following,
always undergo meiotic cell division,
(a) High levels of estrogen triggers the ovulatory
(b) Primary spermatocytes divide by mitotic cell
surge,
division,
(b) Oogonial cells start to proliferate and give rise
(c) Secondary spermatocytes have 23
to functional ova in regular cycles from puberty
chromosomes and undergo second meiotic
onwards,
division,
(c) Sperms released from seminiferous tubules are
(d) Spermatozoa are transformed into spermatids.
highly motile,
(d) Progesterone level is high during the post-
8. Match between the following representing parts of
ovulatory phase of menstrual cycle.
the sperm and their functions and choose the
correct option.
3. Spot the odd one out from the following structures
with reference to the male reproductive system.
Column A Column B
(a) Rete testis
A. Head (i) Enzymes
(b) Epididymis
B. Middle piece (ii) Sperm motility
(c) Vasa efferentia
(d) Isthmus C. Acrosome (iii) Energy
D. Tail (iv) Genetic material
4. Seminal plasma, the fluid part of semen, is (a) A  (ii), B (iv),C (i), D (iii)
contributed by (b) A  (iv), B (iii),C (i), D (ii)
(i) Seminal vesicle (c) A  (iv), B (i),C (ii), D (iii)
(ii) Prostate (d) A  (ii), B (i),C (iii), D (iv)
(iii) Urethra
(iv) Bulbourethral gland
9. Which among the following has 23 chromosomes?
(a) (i) and (ii) (b) (i), (ii) and (iv) (a) Spermatogonia (b) Zygote
(c) (ii), (iii) and (iv) (d) (i) and (iv). (c) Secondary oocyte (d) Oogonia
5. Mature Graafian follicle is generally present in the 10. Match the following and choose the correct
ovary of a healthy human female around option.
(a) 5-8 day of menstrual cycle
A. Trophoblast (i) Embedding of
(b) 11-17 day of menstrual cycle
blastocysts in the
(c) 18-23 day of menstrual cycle
endometrium
(d) 24-28 day of menstrual cycle.
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 B. Cleavage (ii) Group of cells that [2020C]
would differentiate as (a) GH (b) FSH
embryo (c) LH (d) prolactin.
C. Inner cell mass (iii) Outer layer of
blastocysts attached to
the endometrium 18. The correct sequence of hormone secretion from
D. Implantation (iv) Mitotic division of beginning of menstruation is
zygote (a) FSH, progesterone, estrogen
(a) A  (ii), B (i),C (iii), D (iv) (b) Estrogen, FSH, progesterone
(b) A  (iii), B (iv),C (ii), D (i) (c) FSH, estrogen, progesterone
(d) Estrogen, progesterone, FSH.
(c) A  (iii), B (i),C (ii), D (iv)
(d) A  (ii), B (iv),C (iii), D (i)
19. Which of the following hormones are active during
11. Which of the following hormones is not secreted the ovulatory phase of menstrual cycle in a normal
by human placenta? human female?
(a) hCG (b) Estrogens (a) FSH and LH
(c) Progesterone (d) LH (b) LH and Estrogen
(c) FSH and Estrogen
12. Urethral meatus refers to the (d) Estrogen and Progesterone
(a) Urinogenital duct
(b) Opening of vas deferens into urethra
(c) External opening of the urinogenital duct 20. The specific site for fertilization in human female is
(d) Muscles surrounding the urinogenial duct.
(a) Infundibulum
13. Morula is a developmental stage (b) Uterus
(a) Between the zygote and blastocyst (c) Ampulla
(b) Between the blastocyst and gastrula (d) Ampullary isthmic junction.
(c) After the implantation
(d) Between implantation and parturition.
 Assertion Reason
14. The membranous cover of the ovum at ovulation is
(a) Corona radiata 21. Assertion: Parturition is induced by a complex
(b) Zona radiata neuro-endocrine mechanism.
(c) Zona pellucida Reason: At the end of gestation period, the maternal
(d) Chorion. pituitary releases prolactin which causes uterine
contractions,
(a) Both A and R are true and R is the correct
15. Penetration of the sperm in the ovum is followed explanation of A.
by [Term I, 2021 – 22] (b) Both A and R are true and R is not the correct
(a) Formation of first poalr body explanation of A.
(b) Completion of meiosis II
(c) First meiosis (c) A is true but R is false,
(d) Dissolution of zona pellucida. (d) A is false but R is true.

16. After spermiogenesis, the sperm head get 22. Assertion (A): The perimetrium of uterus exhibits
embedded in which of the following cells? strong uterine contractions during child birth.
[2020] Reason (R): Oxytocin released from maternal
(a) Leydig cells (b) Sertoli cells pituitary causes strong uterine contractions,
(c) Germinal epithelium (d) Seminal vesicle (a) Both Assertion (A) and Reason (R) are correct
statements, and Reason (R) is the correct
explanation of the Assertion (A),
17. The hormone that regulates the synthesis and
secretion of androgens in human males is

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 (b) Both Assertion (A) and Reason (R) are correct (d) A is false but R is true.
statements, but Reason (R) is not the correct
explanation of the Assertion (A),
(c) Assertion (A) is correct, but Reason (R) is incorrect 27. Assertion: The testes are situated outside the
statement, abdominal cavity within scrotum.
(d) Assertion (A) is incorrect, but Reason (R) is Reason: Scrotum helps to maintain temperature of
correct statement. [Term I, 2021 – 22] testes lower than the normal body temperature
necessary for spermatogenesis.
(a) Both A and R are true and R is the correct
23. Assertion: All copulations do not lead to fertilisation explanation of A.
and pregnancy. (b) Both A and R are true and R is not the correct
Reason: Fertilisation can only occur if the ovum and explanation of A.
sperms are transported simultaneously to the (c) A is true but R is false,
ampullary- isthmic junction. (d) A is false but R is true.
(a) Both A and R are true and R is the correct
explanation of A.
(b) Both A and R are true and R is not the correct
explanation of A.
 Case Study
(c) A is true but R is false,
(d) A is false but R is true. 28. To answer the questions, study the graphs below
for subject 1 and 2 showing different levels of
certain hormones.
24. Assertion: Progesterone is essential for
maintenance of the endometrium.
Reason: Endometrium is essential for implantation of
embryo.
(a) Both A and R are true and R is the correct
explanation of A.
(b) Both A and R are true and R is not the correct
explanation of A.
(c) A is true but R is false,
(d) A is false but R is true.

25. Assertion: The sex of the baby is determined

by the father and not by the mother.
Reason: 50% of sperms carry the sex chromosome X
while the other 50% carry the sex chromosome Y.
(a) Both A and R are true and R is the correct
explanation of A. (i) The peak observed in Subject 1 and 2 is due to
(b) Both A and R are true and R is not the correct
explanation of A. (a) estrogen
(c) A is true but R is false, (b) progesterone
(d) A is false but R is true. (c) luteinising hormone
(d) follicle stimulating hormone.

26. Assertion: The myometrium undergoes cyclical (ii) Subject 2 has higher level of hormone B, which is
changes during menstrual cycle.
Reason: The endometrium exhibits strong (a) estrogen
contractions during delivery of the baby. (b) progesterone
(a) Both A and R are true and R is the correct (c) luteinising hormone
explanation of A. (d) follicle stimulating hormone.
(b) Both A and R are true and R is not the correct
explanation of A.
(c) A is true but R is false,
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 (iii) If the peak of hormone A does not appear in the (a) Which structure passes through the prostate
study for subject 1, which of the following gland and carries sperms and secretion of seminal
statement is true? vesicle?
a) S b) R
(a) Peak of hormone B will be observed at a higher c) T d) P
point in the graph, (b) Assertion (A): Mucus present in the secretion of
(b) Peak of hormone B will be observed at a point bulbourethral gland decreases the number of
lower than what is given in the graph, sperms damaged during ejaculation.
(c) There will be no observed data for hormone B. Reason (B): Mucus lubricates the end of penis and
(d) The graph for hormone B will be a sharp rise lining of the urethra.
followed by a plateau. a) Both A and R are true and R is the correct
explanation of A.
(iv) Which structure in the ovary will remain b) Both A and R are true but R is not the
functional in subject 2? correct explanation of A.
c) A is true but R is false.
(a) Corpus luteum d) A is false but R is true.
(b) Tertiary follicle (c) Which of the following is correct for labelled
(c) Graafian follicle part P?
(d) Primary follicle a) P is rete testis which transports sperms to
outside.
(v) For subject 2 it is observed that the peak for b) P is epididymis which secretes fluid that
hormone B has reached the plateau stage. After nourish the sperms.
approximately how much time will the curve for c) P is rete testis which lies along inner side of
hormone B descend? each testis and stores the sperms.
d) P is epididymis that carry sperms and
(a) 28 days (b) 42 days secretion of seminal vesicles.
(c) 180 days (d) 280 days (d) Identify the correctly matched pair.
a) S - Seminal vesicle
(vi) Which of the following statements is true about b) Q - Vasa efferentia
the subjects? c) T - Cowper’s gland
(a) Subject 1 is pregnant. d) R - Ejaculatory duct
(b) Subject 2 is pregnant. (e) Which statement is incorrect for Q?
(c) Both subject 1 and 2 are pregnant a) It constitutes male sex accessory duct.
(d) Both subject 1 and 2 are not pregnant. b) It arises from rete testis.
[Term I, 2021 – 22] c) Q are only 2 in number.
d) It carries spermatozoa from epididymis to
ejaculatory duct.
29. Read the text carefully and answer the questions:  Questions
Human male reproductive system comprises of a
pair of testes, primary sex organs associated with
30. Write the location and functions of the following in
formation of gametes and production of sex
human testes:
hormone. Study the given figure of human male
(i) Sertoli cells
reproductive system and answer the following
(ii) Leydig cells
questions.
31. What are spermatogonia? How does it increase in
number?
32. In our society the women are often blamed for
giving birth to daughters. Can you explain why this
is not correct?
33. Explain the importance of syngamy and meiosis in
a sexual life cycle of an organism.

34. What is spermatogenesis? Briefly describe the

process of spermatogenesis.

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 OR 43. (i) Arrange the following hormones in sequence of
Give a schematic representation showing the their secretion in a pregnant woman.
events of spermatogenesis in human male. (ii) Mention their source and the function they
perform:
35. Name the hormones involved in regulation of hcG; LH; FSH; Relaxin.
spermatogenesis. OR *Explain the hormonal
control of spermatogenesis in humans. 44. With the help of diagram describe the
structure of a sperm.
36. Name the functions of the following: OR
(i) Corpus Luteum Describe the structure of Human sperm.
(ii) Endometrium OR
(iii) Acrosome Draw a diagram of human sperm. Label only those parts
(iv) Sperm tail along with their functions that assist the sperm to reach
(v) Fimbriae and gain the entry into the female gamete.

37. Write the specific location and the functions of 45. State from where do the signals for parturition
the following cell in human male : originate in human females.
(i) Leydig cells
(ii) Sertoli cells 46. Write the effect of the high concentration of LH on
(i) Primary spermatocyte Explain the role of any mature Graafian follicle.
two accessory glands in human reproductive
system. 47. Draw a well labelled diagram of male reproductive
system. OR
38. Where does the fertilisation occur in humans? Draw a labelled diagrammatic view of human male
Explain the events that occur during the process. reproductive system.
OR
Explain the events taking place at the time of 48. Draw a labelled diagram of a section through ovary.
fertilisation of an ovum in a human female. OR
Draw a sectional view of human ovary and label the
39. Trace the development of the zygote up to its different follicular stages, ovum and
implantation in the uterus. Corpus Luteum.

40. When and where are primary oocytes formed in a 49. Draw a labelled diagram of a Graafian follicle?
human female ? Trace the development of these
oocytes till ovulation (in menstrual cycle). How do 50. Construct a flow chart exibiting sequential events of
gonadotropin influence this developmental oogenesis.
process?
51. Differentiate between Spermatogenesis and
41. (i) Explain the menstrual phase in a human female. Oogenesis.
State the levels of ovarian and pituitary hormones
during this phase. 52. Differentiate between spermatogenesis and
(ii) Why is follicular phase in the menstrual cycle spermiogenesis.
also referred as proliferative phase ? Explain.
(iii) Explain the events that occur in a graafian 53. Mention the difference between spermiogenesis
follicle at the time of ovulation and thereafter. and spermiation.

42. (i) Differentiate between spermatogenesis and 54. Differentiate between Vas deferens and Vas
oogenesis on the basis of : efferens.
(a) Time of initiation of the process 55. Differentiate between Primary sex organs and
(b) Site of completion of the process Secondary sex organs.
(c) Nature of meiotic division undergone by
gamete mother cells 56. Why are the human testes located outside the
(ii) Name the hormones and state their role abdominal cavity? Name the pouch in which they
invovled in controlling spermatogenesis in humans. are present.

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57. Write the location and functions of the (i) helps it reaching to the ovum
following in human testes: (ii) providing energy for it to reach the ovum,
(a) Sertoli cells (b) Leydig’s cells (iii) helping it to gain entry into the ovum.
58. (a) Name the hormone that initiates spermato
genesis in humans. Describe the process of 59. (a) Explain the process of fertilisation in human,
spermatogenesis in sequence mentioning the (b) Name the embryonic stage that gets
ploidy of the cells at each step, implanted in human females. Explain the process
(b) Draw the diagram of a mature human sperm and of implantation.
label the parts that

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 Sure Shot Questions
Chapter – 03
Reproductive Health
 MCQ Soln. (a) : The national level approach towards
building a reproductively healthy society began
1. The method of directly injecting a sperm into ovum with 'family planning' programmes in 1951.
in assisted reproductive technology is called
(a) GIFT (b) ZIFT 6. Emergency contraceptives are effective if fused
(c) ICSI (d) ET. within
(a) 72 hrs of coitus
(b) 72 hrs of ovulation
2. Increased IMP and decreased MMR in a population (c) 72 hrs of menstruation
will (d) 72 hrs of implantation.
(a) cause rapid increase in growth rate
(b) result in decline in growth rate 7. Choose the right one among the statements given
(c) not cause significant change in growth rate below,
(d) result in an explosive population. (a) lUDs are generally Inserted by the user herself,
(b) lUDs increase phagocytosis reaction in the
3. Intensely lactating mothers do not generally uterus,
conceive due to the (c) lUDs suppress gametogenesis.
(a) suppression of gonadotropins (d) lUDs once inserted need not be replaced.
(b) hypersecretion of gonadotropins
(c) suppression of gametic transport 8. Following statements are given regarding MTP.
(d) suppression of fertilisation. Choose the correct options given below,
(i) MTPs are generally advised during first trimester,
4. Sterilisation techniques are generally fool proof (ii) MTPs are used as a contraceptive method,
methods of contraception with least side effects. (iii) MTPs are always surgical,
Yet, this is the last option for the couples because (iv) MTPs require the assistance of qualified medical
(i) It Is almost irreversible personnel,
(ii) of the misconception that it will reduce sexual (a) (ii) and (iii) (b) (i) and (iii)
urge/drive (c) (i) and (iv) (d) (i) and (ii)
(iii) it is a surgical procedure
(iv) of lack of sufficient facilities in many parts of the 9. From the sexually transmitted diseases mentioned
country. below, identify the one which does not specifically
Choose the correct option, affect the sex organs?
(a) (i) and (iii) only (b) (ii) and (iii) only (a) Syphilis
(c) (ii) and (iv) only (d) (i), (ii), (iii) and (iv) (c) Gonorrhea
(b) AIDS
5. A national level approach to build up a (d) Genital warts
reproductively healthy society was taken up in our
country in 10. Condoms are one of the most popular
(a) 1950s (b) 1960s contraceptives because of the following reasons,
(c) 1980s (d) 1990s. (a) These are effective barriers for insemination,
(b) They do not interfere with coital act.

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 (c) These help in reducing the risk of STDs, g the
(d) All of the above cervix
(D) Tubecto (iv Semen
11. Choose the correct statement regarding the ZIFT my ) contain
s no
procedure,
sperms
(a) Ova collected from a female donor are (a) (A)-(i),(B)-(ii),(C)-{iii).(D)-{iv)
transferred to the Fallopian tube to facilitate (b) (A)-(ii),(B)-(iii),(C)-(iv),(D)-(i)
zygote formation, (c) (A)-(iii),(B)-(iv),(C)-(ii),(D)-(i)
(b) Zygote is collected from a female donor and (d) (A)-(iv),(B)-(i),(C)-(iii),(D)-(ii)
transferred to the Fallopian tube,
(c) Zygote is collected from a female donor and 15. Listed below are all venereal diseases except
(a) Genital warts (b) Ascariasis
transferred to the uterus,
(c) Trichomoniasis (d) Hepatitis – B.
(d) Ova collected from a female donor and
transferred to the uterus. 16. An infertile couple was advised to undergo in vitro
fertilisation by the doctor. Out of the options given
12. The correct surgical procedure as a contraceptive below, select the correct stage for transfer to the
method is fallopian tube for successful results,
(a) Zygote only
(a) ovariectomy (b) hysterectomy
(b) Zygote or early embryo upto 8 blastomeres
(c) vasectomy (d) castration. (c) Embryos with more than 8 blastomeres
(d) Blastocyst Stage
13. Diaphragms are contraceptive devices used by the
females. Choose the correct option from the 17. A female undergoing IVF treatment has blocked
statements given below, fallopian tubes. The technique by which the
(i) They are introduced into the uterus, embryo with more than 8 blastomeres will be
transferred into the female for further
(ii) They are placed to cover the cervical region,
development is
(iii) They act as physical barriers for sperm entry, (a) ZIFT (b) GIFT
(iv) They act as spermicidal agents, (c) IUT (d) Al.
(a) (i) and (ii) (b) (i) and (iii)
(c) (ii) and (iii) (d) (iii) and (iv) 18. Given below are column A with a list of certain
Assisted Reproductive Technologies (ART) and in
14. Given below are four contraceptive methods and Column B 8the procedures followed during ART:
their modes of action. Select the correct match. Column A Column B
S.N Method S. Mode S.No. Name of S.No. Procedures
o. N of ART
o. action (A) GIFT (i) Transfer of
(A) Condom (i) Ovum ovum from a
not donor into
able to the fallopian
reach tube of
fallopia another
n tube female.
(B) Vasecto (ii) Preven (B) ICSI (ii) Transfer of
my ts seemen from
ovulati the donor
on into the
(C) Pill (iii Preven vagina of the
) ts female.
sperm (C) ZIFT (iii) Injecting
reachin sperms
directly

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 into the (d) (A) is false but (R) is true. [2021C]
ovum.
(D) IUI (iv) Transfer 22. Assertion (A); Lactational amenorrhea is the
of early natural method of contraception.
embryos Reason (R): It increases the phagocytosis of sperm,
into the (a) Both (A) and (R) are true and (R) is the correct
fallopian explanation of (A),
tube. (b) Both (A) and (R) are true and (R) is not the
Choose the option where ART correctly matches correct explanation of (A),
with the procedure. (c) (A) is true but (R) is false,
(a) (A)-(i),(B)-(ii).(C)-(iii),(D)-(iv) (d) (A) is false but (R) is true.
(b) (A)-(iv), (B)-(i), (C)-(ii), (D)-(iii)
(c) (A)-(iv),(B)-(iii),(C)-(i),(D)-(ii) 23. Assertion (A): Saheli, an oral contraceptive for
(d) (A)-(i),(B)-(iii).(C)-(iv).(D)-(ii) females, contains a steroidal preparation.
Reason (R): It is a “once a weak” pill with very few
 Assertion Reasoning side effects.
(a) Both (A) and (R) are true and (R) is the correct
explanation of (A),
19. Assertion (A): Determining the sex of an unborn (b) Both (A) and (R) are true and (R) is not the
child followed by MTP is an illegal practice. correct explanation of (A),
Reason (R): Amniocentesis is a practice to test the (c) (A) is true but (R) is false,
presence of genetic disorders also. (d) (A) is false but (R) is true.

(a) Both (A) and (R) are true and (R) is the correct 24. Assertion (A): Tubectomy is a sterilisation
explanation of (A). procedure advised for females as a terminal
(b) Both (A) and (R) true, but (R) is not the correct method.
explanation of (A). Reason (R) : In tubectomy, a small part of the
(c) (A) is true, but (R) is false. fallopian tube is removed or tied up blocking
(d) (A) is false, but (R) is true. gamete transport thereby preventing conception,
(a) Both (A) and (R) are true and (R) is the correct
20. Assertion (A): Reproductive and Child Health Care explanation of (A),
(RCH) programme was initiated in India in 1951 to (b) Both (A) and (R) are true and (R) is not the
attain total reproductive health as a social goal. correct explanation of (A),
Reason (R): Audio-visual and print media (c) (A) is true but (R) is false,
awareness was created among reproduction (d) (A) is false but (R) is true.
related aspects under the programme,
25. Assertion (A): Our laws permit legal adoption and it
(a) Both (A) and (R) are true and (R) is the correct is as yet, one of the best methods for childless
explanation of (A), couples looking for parenthood.
(b) Both (A) and (R) are true and (R) is not the Reason (R): Emotional, religious and social factors
correct explanation of (A), are also no deterrents in the legal adoption of
(c) (A) is true but (R) is false, orphaned and destitute children in India,
(d) (A) is false but (R) is true. (a) Both (A) and (R) are true and (R) is the correct
explanation of (A),
21. Assertion (A): Statutory ban on amniocentesis for (b) Both (A) and (R) are true and (R) is not the
sex-determination is to legally check increasing correct explanation of (A),
female feticide. (c) (A) is true but (R) is false.
Reason (R): In amniocentesis, some of the amniotic (d) (A) is false but (R) is true.
fluid that has the developing fetus is taken to
analyse the chromosomes in the fetal cells.
(a) Both (A) and (R) are true and (R) is the correct
 Case Study
explanation of (A).
(b) Both (A) and (R) are true and (R) is not the correct 26. The so-called test tube babies are produced by
explanation of (A). the technique of "in vitro fertilisation”. It is a form
(c) (A) is true but (R) is false.

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 of assisted reproductive technologies (ART). The and of husband (Y) is found to be 300 million/mL,
steps of ART include: the ART recommended to husband (X) and
husband (Y) respectively by the medical
1. Administration of gonadotropins or practitioner will be
Clomiphene Citrate to the woman.
(a) ICSI and ZIFT (b) ZIFT and ICSI
2. Aspiration of several ova (secondary oocytes) (c) IUT and IUI (d) GIFT and ZIFT.
by laparoscopy.
(v) Generally before the implantation of the
3. Collection of the sperm from the husband/ embryo the woman is administered progesterone
donor semen. in the procedure to make the

4. Incubation of ovum and the sperm together in (a) endometrium of the uterus receptive
special media and environment.\ (b) ampulla of the oviduct receptive
(c) infundibulum of the oviduct receptive
5. Fertilisation and early development of the (d) myometrium of the uterus receptive.
embryo in the culture plate.
(vi) The technique that would be used to implant
6. Implantation of the 8-celled embryos (or more) the embryo, in case the oviducts of the woman are
in the uterine cavity. blocked by an obstruction. [Term I, 2021 – 22]
Answer the given questions on the basis of
understanding of the above given case. (a) GIFT (b) IUT
(c) IUI (d) ICSI
(i) The reason for using the above technique is
I. There may be inadequate motility of 27. Read the text carefully and answer the questions:
spermatozoa. A technique known as amniocentesis is used to
II. There may be obstruction of the uterine tube. determine fetal abnormalities. This test is based on
III. There may be underdeveloped ovaries. the chromosomal pattern in amniotic fluid.
IV. There may be plug in the cervical canal. However, this technique is legally banned now –
Choose the correct option.

(a) I and III (b) III and IV

(c) I and II (d) II and IV

(ii) Gonadotropins in the above technique are

administered to the woman to stimulate

(a) Formation of ovarian follicles

(b) Growth of ovarian follicles
(c) Formation of corpus luteum
(d) Growth of corpus luteum. (a) Identify X and Y in the above given figure.
(b) What is the function of Z?
(iii) The ovum (secondary oocytes) are aspirated
using laparoscopy from (c) A pregnant woman wanted to know if her child
is suffering from jaundice. Can this be diagnosed
(a) primary follicle (b) secondary follicle by amniocentesis?
(c) graafian follicle (d) corpus luteum.
(d) Name a non - invasive technique of detecting
(iv) In the above case if the sperm count in each foetal disorder?
milliliter of husband (X) is less than 20 million/mL

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 Questions Do you agree? Give reasons in support of your
answer.
28. What actually is done in vasectomy?
40. Amniocentesis for sex determination is banned in
our country. Is this ban necessary? Comment.
29. Mention one positive and one negative application
41. Explain various natural and artificial methods to
of amniocentesis.
avoid sperm fertilising an ovum.

30. What is Assisted Reproductive Technology (ART)? 42. Give differences between vasectomy and
tubectomy.

31. A woman has certain queries as listed below, 43. (a) Explain the mode of action of 𝐶𝑢++ releasing
before starting with contraceptive pills. Answer 𝑙𝑈𝐷𝑠 as a good contraceptive. How is hormone
them: releasing 𝑙𝑈𝐷 different from it?
(b) Why is ′𝑆𝑎ℎ𝑒𝑙𝑖′ a preferred contraceptive by
women (any two reasons)? (2020)
32. Mention the role of ‘genetic mother’ in MOET.
44. (a) List any four characteristics of an ideal
contraceptive.
33. Our government has intentionally imposed strict (b) Name two intrauterine contraceptive devices
conditions for M.T.P. in our country. Justify giving a that affect the motility of sperms. (2016)
reason.
OR
Give one reason to justify statutory ban on 45. Name two hormones that are constituents of
amniocentesis. contraceptive pills. Why do they have high and
effective contraceptive value? Name a commonly
prescribed non-steroidal oral pill. (2016)
34. (i) List any four characteristics of an ideal
contraceptive. 46. Our government has intentionally imposed strict
(ii) Name two intra-uterine contraceptive devices conditions for MTP in our country. Justify giving a
that affect the motility of sperms. reason.

35. How do copper and hormone releasing IUD’s act as 47. (a) Name any two copper releasing 𝑙𝑈𝐷𝑠.
contraceptives? Explain. (b) Explain how do they act as effective
contraceptives in human female.
36. Write a note on Sexually Transmitted Disease.
Explain in brief giving one example. 48. A woman has certain queries as listed below,
before starting with contraceptive pills. Answer
them:
37. (i) Mention the problems that are taken care of by (a) What do contraceptive pills contain and how do
Reproduction and Child Health Care programme. they act as contraceptives?
(ii) What is amniocentesis and why there is a (b) What schedule should be followed for taking
statutory ban on it? these pills?

38. (a) lUDs are said to be effective contraceptives. 49. (a) List any four characteristics of an ideal
Name any two commonly used lUDs and write contraceptive.
their mode of actions, (b) Name two intrauterine contraceptive devices
(b) When is sterilisation advised to married that affect the motility of sperms.
couples? How is it carried out in a human male and
a female, respectively? Ans. (a) An ideal contraceptive must have the
following four characteristics:
39. Medically it is advised to all young mothers that It must be safe and user friendly,
breastfeeding is the best for their newborn babies.

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 It must be easily available, It must be reversible to produce functional gametes and should look for
with little or no side effects, an ART (Assisted Reproductive Technique). Name
It should not interfere with the sexual drive, desire the ART and the procedures involved that you can
or sexual act of the user, suggest to them to help them bear a child.
(b) CuT and Multiload 375 are two copper
releasing lUDs that affect the motility of the 54. A couple where both husband and wife are
sperms. producing functional gametes, but the wife is still
unable to conceive, is seeking medical aid.
50. Name and explain the surgical method advised to Describe any one method that you can suggest to
human males and females as a means of birth this couple to become happy parents.
control. Mention its one advantage and one
disadvantage. 55. Suggest and explain any three Assisted
(2014) Reproductive Technologies (ART) to an infertile
couple.
51. (a) 𝑙𝑈𝐷𝑠 are said to be effective contraceptives.
Name any two commonly used 𝑙𝑈𝐷𝑠 and write
their mode of actions.
(b) When is sterilisation advised to married 56. (a) List any two reasons other than physical and
couples? How is it carried out in a human male and congenital disorders for causing infertility in
a female, respectively? couples.
(b) Explain how IVF as a technique helped childless
52. Name two hormones that are constituents of couples in having children.
contraceptive pills. Why do they have high and (c) Compare GIFT and ICSI.
effective contraceptive value? Name a commonly
prescribed non-steroidal oral pill. [Al 2016]

53. After a brief medical examination, a healthy

couple came to know that both of them are unable

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 Sure Shot Questions
Chapter – 04
Principles of Inheritance and Variation
 MCQ distance between the two, i.e., two linked genes
show higher frequency of crossing over
1. All genes located on the same chromosome (recombination) if the distance between them is
(a) Form different groups depending upon their higher and lower frequency if the distance is small.
relative distance But distance between gene has a direct relationship
(b) Form one linkage group with percentage of recombination because with
(c) Will not from any linkage groups increase in distance between genes, percentage of
(d) Form interactive groups that affect the phenotype. recombination increases.

Soln. (b) : Linked genes are the genes which occur on 4. If a genetic disease is transferred from a
the same chromosome. A linkage group is a physical phenotypically normal but carrier female to only
association of linked genes which are normally some of the male progeny, the disease is
inherited together except for crossing over. (a) autosomal dominant (b) autosomal recessive (c)
sex-linked dominant (d) sex-linked recessive.
2. Conditions of a karyotype 2n  1 and 2n  2 are
called Soln. (d) : The sex linked recessive disease shows its
(a) aneuploidy (b) polyploidy transmission from unaffected carrier female to
(c) allopolyploidy (d) monosomy. some of the male progeny, e.g., haemophilia. The
heterozyous female (carrier) of haemophilia may
Soln. (a) : The chromosomal disorders are caused due transmit the disease to sons. The possibility of a
to lack or additions or abnormal arrangement of female becoming a haemophilic is extremely rare
one or more chromosomes. Failure of segregation because mother of such a female has to be at least
of chromatids during cell division cycle results in the carrier and the father should be haemophilic.
gain or loss of chromosome(s), is called aneuploidy.
For example, Down's syndrome results due to gain 5. In sickle cell anaemia glutamic acid is replaced by
of extra copy of chromosome 21. Similarly, Turner's valine.
syndrome results due to loss of an X chromosome Which one of the following triplets codes for valine?
in human females. (a) G G G (b) A A G
(c) G A A (d) G U G
3. Distance between the genes and percentage of
recombination shows Soln. (d): The sickle-cell anaemia is caused by the
(a) A direct relationship substitution of glutamic acid (Glu) by valine (Val) at
(b) An inverse relationship the sixth position of the beta globin chain of the
(c) A parallel relationship haemoglobin molecule. The substitution of amino
(d) No relationship acid in the globin protein results due to the single
base substitution at the sixth codon of the beta
Soln. (a): Linkage is the phenomenon of physical globin gene from GAG to GUG. The mutant
association of gene on a chromosome and haemoglobin molecule undergoes polymerization
recombination is the generation of non-parental under low oxygen tension causing the change in the
gene combinations. Strength of the linkage shape of the RBC from biconcave disc to elongated
between two genes is inversely proportional to the sickle like structure.

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6. Person having genotype l A l B would show the blood Soln. (c) ; Linkage will not result in variations among
group as AB. This is because of sibiings because linked genes occur on the same
(a) Pleiotropy chromosome and are transmitted together. In
(b) Co-dominance linkage there is a tendency to maintain the parental
(c) Segregation gene combinations except for occasional
(d) Incomplete dominance. crossovers.

Soln. (b) 11.Mendel's law of independent assortment holds

good for genes situated on the
7. ZZ/ZW type of sex determination is seen in (a) non-homologous chromosomes
(a) platypus (b) snails (b) homologous chromosomes
(c) cockroach (d) peacock. (c) extra nuclear genetic element
(d) same chromosome.
Soln. (d): ZZ/ZW type of sex determination is seen in
birds and some reptiles. Soln. (b) : According to the Mendel's law of
Independent Assortment, the pairs of "factors"
8. A cross between two tall plants resulted in offspring
segregate independently of each other when germ
having few dwarf plants. What would be the
cells are formed. Homologous chromosomes
genotypes of both the parents?
synapse during meiosis and then separate to
(a) TT and Tt (b) Tt and Tt
segregate independently Into different cells which
(c) TT and TT (d) Tt and tt
establishes the quantitative basis for segregation
Soln. (b) and independent assortment of hereditary factors

9. In a dihybrid cross, if you get 9:33:1 ratio it denotes 12.Occasionally, a single gene may express more than
that one effect. The phenomenon is called
(a) the alleles of two genes are interacting with each (a) Multiple allelism
other (b) Mosaicism
(b) it is a multigenic inheritance (c) Pleiotropy
(c) it is a case of multiple allelism (d) Polygeny.
(d) the alleles of two genes are segregating
Soln. (c)
independently.
13.In a certain taxon of insects some have 17
Soln. (d) : Cross involving two contrasting characters is
chromosomes and the others have 18
called dihybrid cross or a two factor cross. The two
chromosomes. The 17 and 18 chromosome-bearing
factors of each trait assort at random and
organisms are
independent of the factors of other traits at the
(a) males and females, respectively
time of meiosis (gametogenesis) and get randomly
(b) females and males, respectively
as well as independently rearranged in the offspring
(c) all males (d) all females.
producing both parental and new combinations of
traits. This explained the law of independent Soln. (a) : In certain insects XX - XO type of sex
assortment given by Mendel. determination is observed where females have
autosomes + 1 pair of sex chromosomes while
10.Which of the following will not result in variations
males have autosomes + 1 sex chromosome.
among siblings?
(a) Independent assortment of genes 14.The inheritance pattern of a gene over generations
(b) Crossing over among humans is studied by the pedigree analysis.
(c) Linkage Character studied in the pedigree analysis is
(d) Mutation equivalent to
(a) quantitative trait (b) Mendelian trait

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(c) polygenic trait (d) maternal trait. Soln. (c): If mother and father of a person with ‘O’
blood group have ‘A’ and ‘B’ blood group then both
Soln. (b) : Pedigree analysis is study of pedigree for the mother and father will be heterozygous for ‘A’ and
transmission of particular trait and finding the ‘B’ blood group respectively.
possibility of absence or presence of that trait in
homozygous or heterozygous state in a particular 17. How many types of gametes would be produced if
Individual. It indicates that Mendel's principles are the genotype of a parent is AaBB?
also applicable to human genetics with some [Term I, 2021 – 22]
(a) 1 (b) 2
modifications like quantitative inheritance, sex
(c) 3 (d) 4
linked characters and other linkages.
Ans. (b): A parent having genotype AaBB is
15. It is said that Mendel proposed that the factor
heterozygous for only character A. Thus,
controlling any character is discrete and
Total number of gametes = 2n = 21 = 2,
independent. His proposition was based on the
Where n = no. of heterozygous pair
(a) Results of F3 generation of a cross
So, the two types of gametes will be AB and aB.
(b) Observations that the offspring of a cross made
between the plants having two contrasting
18. In Antirrhinum, RR is phenotypically red flowers, rr
characters shows only one character without any is white and Rr is pink.
blending Select the correct phenotypic ratio in F1 generation
(c) Self pollination of F1 offsprings when a cross is performed between RR x Rr.
(d) Cross pollination of F1 generation with recessive [Term I, 2021 – 22]
parent. (a) 1 red : 2 pink : 1 white
(b) 2 pink : 1 white
Soln. (b): When plants having two contrasting (c) 2 red : 2 pink
characters are crossed, F1 generation shows (d) All pink
dominant phenotype and the recessive phenotype
Ans. (c): The cross between RR and Rr:
is not lost but appears in F2 generation. This
suggested that there is no blending of Mendelian
factors in F1 generation but they stay together and
only one of them is expressed. At the time of
formation of gametes, these two factors obviously
separate or segregate, otherwise recessive type will
not appear in F2 generation. The gametes which are
formed are always pure for a particular character.
That is why it is called as ‘principle of segregation’
or ‘law of purity of gametes’.

16. Mother and father of a person with 'O' blood group

have 'A' and 'B' blood group respectively. What
would be the genotype of both mother and father? 19. What would be the genotype of the parents if the
offspring have the phenotypes in 1 : 1 proportion?
(a) Mother is homozygous for 'A' blood group and
[Term I, 2021 – 22]
father is heterozygous for 'B'. (a) Aa x Aa (b) AA x AA
(b) Mother is heterozygous for 'A' blood group and (c) Aa x AA (d) Aa x aa
father is homozygous for 'B'.
(c) Both mother and father are heterozygous for 'A' Ans. (d): The genotype of parent will be
and 'B' blood group, respectively,
(d) Both mother and father are homozygous for 'A' and
'B' blood group, respectively.

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 16 plants are formed in which 9 are tall green, 3 are
tall yellow, 3 are dwarf green and 1 dwarf yellow.
So, the number of tall plants (9+3) out of 80 plants is
12
  80  60
16

Phenotypic ratio = 1 : 1 23.Select the pair – that is not correct.

(a) Pleiotropy : Sickle cell anaemia
20.Genotypic ratio of 1 : 2 : 1 is obtained in a cross (b) Linkage : Drosophila
between [Term I, 2021 – 22] (c) Incomplete dominance: Antirrhinum
(d) Co – dominance : ABO blood group.
(a) AB x AB (b) Ab x Ab
(c) Ab x ab (d) ab x ab.
Ans. None of the options is correct.
Ans. (b): The selfing between Ab results in In human beings, pleiotropy is exhibited by sickle cell
anemia in which genes causing this disorder alter
the type of haemoglobin and also change the form
of RBCs. Morgan defined linkage on basis of his
breeding experiments in fruit fly (Drosophila).
Inheritance of flower colour in snapdragon
Genotypic ratio – AA : Ab : bb (Antirrhinum) is an example of incomplete
1:2:1 dominance. ABO blood grouping is an example of
co-dominance.
21.Polydactyly (six-fingered hands) is a genetic
24.Which of the following combination of
condition due to a dominant allele (P) over
chromosome numbers represents the correct sex
recessive allele (p). If a six-fingered woman and a
determination pattern in honey bees?
five-fingered man have a five-fingered child, the
(a) Male 32, Female 16 (b) Male 16, Female 32
genotype of the parents and the child would be
(c) Male 31, Female 32 (d) Female 32, Male 31
[Term I, 2021 – 22]
Mother Father Child
Ans. (b): ln honey bees, haplo-diploid mechanism of
(a) PP pp Pp
sex determination is present, in which male or
(b) Pp pp pp
(c) Pp Pp pp drone is haploid having 16 chromosomes and
(d) pp PP Pp female or queen is diploid having 32 chromosomes.

Ans. (b): In polydactyly (six fingered hands), the allele  Assertion Reason
for Polydactyly (P) is dominant over recessive allele
(p) for five-fingered hands. Thus, the child with five 25. Assertion (A) : In a monohybrid cross between tall
fingered (pp) must have a mother with genotype plants and dwarf plants, the F2 generation showed
(Pp) and father with genotype (pp). tall and dwarf plants in the ratio of 3; 1.
Reason (R): There is no blending of traits/characters in
the Fj generation,
22.A cross is made between tall pea plants having
(a) Both (A) and (R) are true and (R) is the correct
green pods and dwarf pea plants having yellow
explanation of (A),
pods. In the F2 generation, out of 80 plants how
(b) Both (A) and (R) are true and (R) is not the correct
many are likely to be tall plants?
explanation of (A),
[Term I, 2021 – 22]
(c) (A) is true, but (R) is false,
(a) 15 (b) 20
(d) (A) is false, but (R) is true. [2023]
(c) 45 (d) 60
Ans. (a): In a monohybrid cross between tall and dwarf
Ans. (d): According to the dihybrid cross, if tall pea
plants, a 3 : 1 ratio is showed in F2 generation
plant with green pods (TTGG) is crossed with dwarf
suggest that contrasting characters of alleles do not
pea plant with yellow pods (ttgg), in F2 generation
show any blending.

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 29.Assertion: In humans, the gamete contributed by
26.Assertion (A): When white eyed, yellow bodied the male determines whether the child produced
Drosophila females were hybridized with red eyed, will be a male or a female.
brown – bodied males; and F1 progeny was Reason: Sex in humans is a polygenic trait depending
intercrossed, F2 ratio deviated from 9 : 3 : 3 : 1. upon a cumulative effect of some genes on X
Reason (R): When two genes in a dihybrid are on the chromosome and some on Y chromosome.
same chromosome, the proportion of parental gene (a) If both assertion and reason are true and reason is
combinations is much higher than the non – the correct explanation of assertion.
parental type. [2022 – 23] (b) If both assertion and reason are true but reason is
(a) Both (A) and (R) are true and (R) is the correct not the correct explanation of assertion.
explanation of (A). (c) If assertion is true but reason is false.
(b) Both (A) and (R) are true and (R) is not the correct (d) If both assertion and reason are false.
explanation of (A).
(c) (A) is true but (R) is false. Sol. (c)
(d) (A) is false but (R) is true.
30.Assertion: In pigeons, females are heterogametic
Ans. (a) and males are homogametic.
Reason: In pigeons, females have ZW sex
27.Assertion (A): when the two genes in dihybrid cross chromosomes and males have ZZ sex
are situated on the same chromosome, the chromosomes.
proportion of parental gene combinations is much (a) If both assertion and reason are true and reason is
higher than non – parental type. the correct explanation of assertion.
Reason (R): Higher parental gene combinations can be (b) If both assertion and reason are true but reason is
attributed to crossing over between two genes. not the correct explanation of assertion.
[Term I, 2021 – 22] (c) If assertion is true but reason is false.
(a) Both (A) and (R) are true and (R) is the correct (d) If both assertion and reason are false.
explanation of (A)
(b) Both (A) and (R) are true and (R) is not the Sol. (a)
correct explanation of (A)
(c) (A) is true but (R) is false 31.Assertion: When yellow bodied, white-eyed
(d) (A) is false but (R) is true Drosophila females were hybridised with brown
bodied, red-eyed males; the two genes segregate
Ans. (c): When the two genes are present on the same independently of each other.
chromosome, at the time of gamete formation Reason: The two genes are on the different
chromosomes and the proportion of parental gene
during meiosis, the tightly linked genes are unable
combinations is much higher than the non-parental
to separate because there is no crossing over and type.
the proportion of parental genotype is much higher (a) If both assertion and reason are true and reason is
than the non-parental type. the correct explanation of assertion.
(b) If both assertion and reason are true but reason is
(i) types of hereditary variations that can be seen with not the correct explanation of assertion.
lower microscope. (c) If assertion is true but reason is false.
(d) If both assertion and reason are false.
28.Assertion: Insects have homogametic females.
Sol. (d)
Reason: In insects, male shows XX sex chromosome
and female shows XY sex chromosome.
(a) If both assertion and reason are true and reason is
the correct explanation of assertion.
(b) If both assertion and reason are true but reason is
not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If both assertion and reason are false.
Sol. (c)

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 (e) Assertion (A): If a man with attached earlobe (ee)
and hairy pinna married a woman with attached
 Case Study earlobes (ee) than only 100% chances of sons to
have hairy pinna.
32. Read the text carefully and answer the questions: Reason (R): If a male with attached earlobe sparse hair
While studying inheritance of characters, a teacher on pinna married a female with attached earlobe
gave the example of inheritance of attached then all son have an attached earlobe.
earlobe and hypertrichosis of the ear to her a) Both A and R are true and R is the correct
students. A man with attached earlobes and explanation of A.
extensive hair on pinna married a woman having b) Both A and R are true but R is not the correct
free earlobes. The couple had four children, one explanation of A.
son with attached earlobes and hairy pinna, one c) A is true but R is false.
son with free earlobes and hairy pinna and two d) A is false but R is true.
daughters with attached earlobes. One of the
daughters married a man with free earlobes and Ans. (a). (a) Y linked trait
sparse hair on pinna. Teacher said if this couple Explanation: Y linked trait
would have sons there would be equal chances for
both having free or attached earlobes and sparse (b). (a) 100%
hair on pinnae. Explanation: If a man with attached earlobe (ee)
(a) Hypertrichosis of the ear is and hairy pinna married a woman with attached
a) Y linked trait earlobes (ee) than100% chances of sons to have
b) Autosomal dominant trait hairy pinna as hypertrichosis or hairy pinna is Y
c) X linked trait linked feature.
d) Autosomal recessive trait
(c). (d) All daughters have an attached earlobe.
(b) If a man with an attached earlobe and hairy pinna
Explanation: If a male with attached earlobe sparse
married a woman with an attached earlobe then
hair on pinna married a female with attached
what would
earlobe then all daughters have an attached
be the chances of son having hairy pinna?
earlobe.
a) 100% b) 75%
c) 50% d) 0%
(c) A male with attached earlobe, sparse hair on
pinna married a female with an attached earlobe.
Which of the following is correct regarding their
progenies?
a) 50% sons have attached earlobe with hairy pinna
and 50% sons have a free earlobe.
b) 50% daughters have an attached earlobe whereas
50% daughters have a free earlobe. (d). (c) recessive and dominant traits
c) All sons have a free earlobe with hairy pinna. Explanation: In humans, free earlobes is dominant
d) All daughters have an attached earlobe. over attached earlobes.
(d) Attached and free earlobe are respective example
of (e). (d) 0%
a) Dominant and dominant traits Explanation: If a female with attached earlobes (ee)
b) Recessive and recessive traits married a male with free lobe (EE) and sparse hair
c) Recessive and dominant traits on pinna then chance of any progeny to have
d) Dominant and recessive traits attached ear lobe is zero. It can be depicted as
(e) If a female with attached earlobe married a male follows:
homozygous for free earlobe sparse hair on pinna
then what would be the chances of daughter to
have attached earlobe?
a) 100% b) 75%
c) 25% d) 0%

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(f). (c) A is true but R is false.
Explanation: A is true but R is false. (b). When a man whose father was colourblind and
mother was normal (i.e., normal man XY) marries a
33.Read the text carefully and answer the questions: woman whose father was haemophilic and mother
Haemophilia is a sex linked disease which is also was normal (i.e., carrier haemophilic woman XhX),
known as bleeders disease as the patient will then 25% male progenies and 25%female progenies
continue to bleed even from a minor cut since he or carry the gene of haemophilia.
she does not possess the natural phenomenon of
blood clotting due to absence of anti - haemophilic
globulin or factor VIII and plasma thromboplastin
factor IX essential for it. As a result of continuous
bleeding the patient may die of blood loss. Colour
blindness is another type of sex-linked trait in which
the eye fails to distinguish red and green colours.
Vision is however, not affected and the colour blind
can, lead a normal life, reading, writing and driving
(distinguishing traffic lights by their position).
(a) If a haemophilic man marries a woman whose
father
was haemophilic and mother was normal then what
will
be the progenies?
(b) A man whose father was colourblind and mother
was
normal marries a woman whose father was
haemophilic
and mother was normal. What will be their progenies?
[Note: Percentage is from the total number of
progenies.
(c) Does haemophilia is a dominant disease.
(d) Anup is having colourblindness and is married to
Soni who is normal. What is the chance that their
son will have the disease?
Ans.
(a). When a haemophilic man (XhY) marries a
woman whose father was haemophilic and mother
was normal i.e., carrier woman (XXh), then 50%
daughters are carriers and 50% are haemophilic.
This can be explained as follows:

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 42.A teacher wants his or her students to find the
genotype of pea plants bearing purple coloured
flowers in their school garden. Name and explain
the cross that will make it possible.

43.Ina cross between a true-breeding red flowered and

a true-breeding white flowered snapdragon plant,
the F, plants produced pink flowers. Name and
explain the type of inheritance.

(c). No, Haemophilia is sex linked recessive 44. Explain the law of dominance, using a monohybrid
Mendelian disorder. cross.

(d). When Anup who is colourblind (XCY) marries 45.Define and design a test cross.
Soni who is normal (XX) then 0% chances that their
son will have colourblindness. 46.When a cross is made between tall plant with
yellow seed (TtYy) and tall plant with green seed
(Ttyy), what proportions of phenotype in the
offspring could be expected to be?
(i) Tall and green
(ii) Dwarf and green

47.Explain the mechanism of ‘sex determination’ in

birds. How does it differ from that of human
 Questions beings?
34. What is a Test Cross?
48.Give an example of an autosomal recessive trait in
35.A diploid organism is heterozygous for 4 loci, how humans. Explain its pattern of inheritance with the
many types of gametes can be produced? help of a cross.

36.Linkage or crossing-over of genes is alternative of 49.A tall pea plant bearing violet flowers is crossed
each other. Justify with the help of an example. with a tall pea plant bearing white flowers. In the 𝐹1
progeny, there were tall pea plants with white
flowers, tall pea plants with violet flowers, dwarf
37.What is point mutation? Give one example.
pea plants with violet flowers and dwarf pea plant
with white flowers. Work out the cross to show
38.A child has blood group O. If the father has blood how is it possible.
group A and mother blood group B, work out the
genotypes of the parents and the possible 50.(a) Write the scientific name of the organism
genotypes of other offspring? Thomas Hunt Morgan and his colleagues worked
with for their experiments. Explain the correlation
39.A single pea plant in your kitchen garden produces between linkage and recombination with respect to
pods with viable seeds, but the individual papaya genes as studied by them,
plant does not. Explain. (b) How did Sturtevant explain gene mapping while
working with Morgan? [NCERT, 2018]
40.In pea plant, the colour of the flower is either violet
or white, whereas human skin colour shows many 51.Compare in any three ways the choromosomal
gradations. Explain giving reason how it is possible. theory of inheritance as proposed by Sutton and
Bovery with that of experimental results on pea
41.Write the conclusions Mendel arrived at on plant presented by Mendel.
dominance of traits on the basis of monohybrid
crosses that he carried out in pea plants. Explain 52.(a) Explain linkage and recombination as put fouth
why a recessive allele is unable to express itself in a by T.H. Morgan based on his observation with
heterozygous state ? Drsophila melanogaster crossing experiment.

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(b) Write the basis on which Alfred Sturtevant 58.Name the type of cross that would help to find the
explained gene mapping. genotype of a pea plant bearing violet flowers.

53.Mendel published his work on inheritance of 59. Explain in brief about the chromosomal disorders.
characters in 1865, but it remained unrecognized OR
till 1900. Give three reasons for the delay in How does the chromosomal disorder differ from
accepting his work. Mendelian disorders ? Name any two chromosomal
aberration associated disorders. List the
54.A male honeybee has 16 chromosomes whereas its characteristics of the disorders mentioned above
female has 32 chromosomes. Give one reason. that help in their diagnosis.

55.How many chromosomes do drones of honeybee 60.(i) Write the scientific name of the organism
possess? Name the type of cell division involved in Thomas Hunt Morgan and his colleagues worked
the production of sperms by them. with for their experiments. Explain the correlation
between linkage and recombination with respect to
56.Identify and write the correct statement: genes as studied by them.
(a) Drosophila male has one X and one Y chromosome, (ii) How did Sturtevant explain gene mapping
(b) Drosophila male has two X chromosomes. while working with Morgan?

57.State the law of independent assortment. Using 61.A normal couple has a colour-blind child whereas a
Punnett square demonstrate the law of child suffering from thalassemia is born to normal
independent assortment in a dihybrid cross parents. Compare the patten of inheritance of
involving two heterozygous parents. these two trains in the said case. State the reasons
OR how is it possible ?
Work out a typical Mendelian dihybrid cross and state
the law that he derived from it. 62.Give the differences between Back Cross and Test
OR Cross.
Explain Mendel’s law of independent assortment by
taking a suitable example. How did Morgan show the 63.Distinguish between Co-dominance and Incomplete
deviation in inheritance pattern in Drosophila with Dominance.
respect to this law?

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 Sure Shot Questions
Chapter – 05
Molecular Basis of Inheritance
 MCQ
6. The human chromosome with the highest and
least number of genes in them are respectively
1. In a DNA strand that nucleotides are linked
(a) chromosome 21 and Y
together by
(b) chromosome 1 and X
(c) chromosome 1 and Y
(a) Glycosidic bonds
(d) chromosome X and Y.
(b) Phosphodiester bonds
(c) Peptide bonds
7. Who amongst the following scientists had no
(d) Hydrogen bonds.
contribution in the development of the double
helix model for the structure of DNA?
(a) Rosalind Franklin
2. The fact that a purine base always paired through
(b) Maurice Wilkins
hydrogen bonds with a pyrimidine base leads to,
(c) Erwin Chargaff
in the DNA double helix
(d) Meselson and Stahl
(a) the antiparallel nature
8. Which of the following steps in transcription is
(b) the semi-conservative nature
catalysed by RNA polymerase?
(c) uniform width throughout DNA
(d) uniform length in all DNA
(a) Initiation
(b) Elongation
(c) Termination
3. Which of the following statements is the most
(d) All of the above
appropriate for sickle cell anaemia?
9. Control of gene expression takes place at the level
(a) It cannot be treated with iron supplements,
of
(b) It is a molecular disease,
(a) DNA – replication
(c) It confers resistance to acquiring malaria,
(b) Transcription
(d) All of the above
(c) Translation
(d) None of the above.
4. The first genetic material could be
10. Which was the last human chromosome to be
completely sequenced?
(a) protein (b) carbohydrates
(a) Chromosome 1 (b) Chromosome 11
(c) DNA (d) RNA.
(c) Chromosome 21 (d) Chromosome X

11. Which of the following are the functions of RNA?

5. With regard to mature mRNA in eukaryotes
(a) It is a carrier of genetic information from DNA to
(a) Exons and introns do not appear in the mature
ribosomes synthesising polypeptides,
RNA
(b) It carries amino acids to ribosomes,
(b) Exons appear but introns do not appear in the
(c) It is a constituent component of ribosomes,
mature RNA
(d) All of the above
(c) Introns appear but exons do not appear in the
mature RNA
(d) Both exons and introns appear in the mature RNA.
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12. While analysing the DNA of an organism a total So, number of base pairs in euchromatin
number of 5386 nucleotides were found out of containing 2000 nucleosomes will be = 200 x 200 =
which the proportion of different bases were: 40,000 bp
Adenine = 29%, Guanine = 17%, Cytosine = 32%, The length of euchromatin = total no. of base
Thymine = 17%. Considering the 27. Chargaff's pairs x distance between two consecutive bp
rule it can be concluded that = 40,000 bp x 0.34 x 10-9 m/bp
= 13600 x 10-9 m
(a) it is a double stranded circular DNA
(b) it is single stranded DNA 18. If Meselson and Stahl’s experiment is continued
(c) it is a double stranded linear DNA for sixth generations in bacteria, the ratio of heavy
(d) no conclusion can be drawn. 15
N / 15 N : Hybrid 15N/ 14N : light
strands
14
13. The RNA polymerase holoenzyme transcribes N / 14 N containing DNA kin the sixth
(a) the promoter, structural gene and the generation would be [Term I, 2021 – 22]
terminator region
(b) the promoter and the terminator region (a) 1 : 1 : 1 (b) 0 : 1 : 7
(c) the structural gene and the terminator region (c) 0 : 1 : 15 (d) 0 : 1 : 31.
(d) the structural gene only.
19. Origin of replication of DNA in E.coli is shown
14. If the base sequence of a codon in mRNA is 5'- below. Identify the labelled parts (i), (ii), (iii) and
AUG-3', the sequence of tRNA pairing with it must (iv). [Term I, 2021 – 22]
be

(a) 5' - UAC - 3' (b) 5' - CAU - 3'

(c) 5'-AUG-3' (d) 5' - GUA - 3'.

15. The amino acid attaches to the tRNA at its

(a) 5’ – end (b) 3’ – end

(c) anticodon site (d) DHU loop.

16. Total number of nucleotide sequences of DNA (a) (i) – Discontinuous synthesis, (ii) – Continuous
that codes for a hormone is 1530. The proportion synthesis (iii) 3’ end (iv) 5’ end
of different bases in the sequence is found to be (b) (i) – Continuous synthesis, (ii) – Discontinuous
adenine = 34%, guanine = 19%, cytosine = 23%, synthesis (iii) 5’ end (iv) 3’ end
thymine = 19%. (c) (i) – Discontinuous synthesis, (ii) – Continuous
Applying Chargaff’s rule, what conclusion can be synthesis (iii) 5’ end (iv) 3’ end
drawn? (d) (i) – Continuous synthesis, (ii) – Discontinuous
synthesis (iii) 3’ end (iv) 5’ end
(a) It is a double stranded circular DNA.
(b) It is a single stranded DNA.
(c) It is a double stranded linear DNA. 20. Given below is a list of steps Meselson and Stahl
(d) It is a single stranded DNA coiled on histones. carried out in their experiment to prove that DNA
replication is semi – conservative. Select the
17. A stretch of an euchromatin has 200 nucleosomes. option that gives the correct sequence of steps
How many base pairs will there be in the stretch followed by them.
and what would be the length of the typical (i) Bacteria transferred to a N14 medium and sampled
euchromatin? every 20 minutes.
(a) 20,000 bp and 13,000 x 10-9m (ii) All bacteria contain hybrid DNA (N14 DNA and N15
(b) 10,000 bp and 10,000 x 10-9 m DNA).
(c) 40,000 bp and 13,600 x 10-9m (iii) Bacteria grown in N15 medium for many
(d) 40,000 bp and 13,900 x 10-9m generations.
(iv) All bacteria contain N15 DNA.
Ans. (c) : A typical nucleosome contains 200 bp of (v) Bacteria contain either all N14 DNA or all hybrid
DNA helix. DNA. [2023]
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(a) (ii)  (iv)  (iii)  (v)
(b) (i)  (ii)  (v)  (iv)  (iii) 27. Assertion: In transcription, the strand with 3’→5’
(c) (iii)  (iv)  (i)  (ii)  (v) polarity acts as the template strand.
(d) (iv)  (iii)  (ii)  (v)  (i) Reason: The RNA polymerase catalyses the
polymerisation in only one direction, i.e., 5’→3’.
21. A region of coding strand of DNA has the following
nucleotide sequence 5' - ATGCGGC - 3' The 28. Assertion: hnRNA is larger than mRNA.
sequence of bases on mRNA transcribed by this Reason: hnRNA has non-translating introns which are
would be [Term I, 2021 – 22] not required for translation.

(a) 5'- AUGCGGC - 3' (b) 3'- AUGCGGC - 3' 29. Assertion: In Griffith’s experiment, a mixture of
(c) 5'- TACGCCG - 3' (d) 3'- TACGCCG - 5' heat-killed virulent bacteria R and live non-
virulent bacteria S, lead to the death of mice.
22. Given below is a sequence of bases in mRNA of a Reason: ‘Transforming principle’ got transferred from
bacterial cell. Identify the amino acid that would heat-killed R strain to S strain and made it
be incorporated at codon position 3 and codon virulent.
position 5 during the process of its translation. 3'
AUCAGGUUUGUGAUGGUACGA 5'  Case Study
(a) Phenylalanine, Methionine
(b) Cysteine, Glycine 30. Read the text carefully and answer the questions:
(c) Alanine, Proline DNA replication is a complex multistep process
(d) Serine, Valine that requires enzymes, protein factors and metal
ions. DNA replication in eukaryotes occurs in the
 Assertion and Reasoning nucleus during the S - phase of the cell cycle. It is
semi discontinuous in eukaryotes. In prokaryotes,
replication takes place in the cytoplasm. DNA
Directions: In the following questions, a statement of
replication in bacteria occurs prior to fission.
assertion is followed by a statement of reason
Nucleoid or viral chromosome is a single molecule
Mark the correct choice as:
of nucleic acid, it may be linear of circular. The
(a) If both assertion and reason are true and reason is
nucleic acid in a virus is either DNA or RNA but
the correct explanation of assertion.
never both.
(b) If both assertion and reason are true but reason is
not the correct explanation of assertion.
(a) In viral DNA, how many origin of replication are
(c) If assertion is true but reason is false.
present?
(d) If both assertion and reason are false.
a) Multiple b) Twice
c) None of these d) Single
23. Assertion: Primary transcripts in eukaryotes are
non functional.
(b) Select the main enzyme involved in DNA
Reason: Methyl guanosine triphosphate is attached to
replication.
5' - end of hnRNA.
a) DNA ligase
b) DNA dependent DNA polymerase
24. Assertion: The genetic code is degenerate.
c) Helicase
Reason: Most amino acids are coded by more than one
d) Topoisomerase
codon.
(c) Read the given statement and select the option that
25. Assertion: R Frame shift mutations form the
correctly fill in the blanks. Enzyme___ (i)__ acts
genetic basis of proof that codon is a triplet.
over the Ori site and unwinds the two strands of
Reason: Insertion or deletion of one or two bases
DNA by
changes the reading frame from the point of
destroying ___(ii)___bonds,
insertion or deletion.
a) (i) - Unwindase, (ii) - Glycosidic
b) (i) - Helicase, (ii) - Glycosidic
26. Assertion: A single mRNA strand is capable of
c) (i) - Helicase, (ii) - Hydrogen
forming a number of different polypeptide chains.
d) (i) - Unwindase, (ii) – Phosphodiester
Reason: The mRNA strand has termination
codons.

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(d) DNA strand, built up of Okazaki fragments is called: Which of the above - given materials are required
a) Leading strand for transcription?
b) Complementary strand a) (1), (2), (3), (5) and (6)
c) Lagging strand b) All of these
d) Parental strand. c) (1), (2), (3) and (4)
d) (1), (2), (5) and (6)
(e) Select the incorrect statement about DNA
polymerase in eukaryotes. (e) What are regions of transcription unit in a DNA
a) When the RNA primer gets removed the gap is molecule?
filled by DNA polymerase in eukaryotes. a) Structural gene b) Promoter
b) Polymerase a is required for the initiation of c) All of these d) Terminator
replication.
c) Polymerase∈ helps in elongation of lagging (f) Control of gene expression takes place at the level
strand. of:
d) Polymerase δ is largest and main enzyme for a) Transcription b) DNA - replication
DNA replication in eukaryotes. c) None of these d) Translation

31. Read the text carefully and answer the questions:  Questions
The process of copying genetic information from 32. List two essential roles of ribosome during
the template strand of translation.
DNA into RNA is called transcription. It is OR
mediated by RNA polymerase. Transcription takes Mention the role of ribosome in peptide bond
place in the nucleus formation. How does ATP facilitate i?
of eukaryotic cells. In transcription, only a
segment of DNA and only one of the strands is 33. What is Euchromatin and Heterochromatin?
copied into RNA.
(a) Monocistronic structural genes are found in which 34. One of the salient features of the genetic code is
organisms? that it is nearly universal from bacteria to humans.
a) Viruses b) Prokaryotes Mention two exceptions to this rule. Why are some
c) Eukaryote d) Bacteria codes said to be degenerate?

(b) Which enzyme helps in tailing or polyadenylation? 35. Given below are sequences of nucleotides in a
a) All of these particular mRNA and amino acids coded by it :
b) Exonucleases 𝑈𝑈𝑈 − 𝐴𝑈𝐺 − 𝑈𝑈𝐶 − 𝐺𝐴𝐺 − 𝑈𝑈𝐴 − 𝐺𝑈𝐺
c) Poly - A polymerase − 𝑈𝐴𝐴
d) RNA polymerase I 𝑃ℎ𝑒 − 𝑀𝑒𝑡 − 𝑃ℎ𝑒 − 𝐺𝑙𝑢 − 𝐿𝑒𝑢 − 𝑉𝑎𝑙
Write the properties of the genetic code that can be
(c) Assertion (A): A single RNA polymerase in and cannot be correlated from the above given
prokaryotes synthesis all types of RNAs. data.
Reason (R): Prokaryotic RNA polymerase has sigma
(σ) factor. 36. Explain the two factors responsible for conferring
a) Both A and R are true and R is the correct stability to double helix structure of DNA.
explanation of A.
b) Both A and R are true but R is not the correct 37. Following the collision of two trains, a large
explanation of A. number of passengers are killed. A majority of
c) A is true but R is false. them are beyond recognition. Authorities want to
d) A is false but R is true. hand over the dead bodies to their relatives. Name
the modern scientific method and write the
(d) Read the given list of materials. procedure that would help in the identification of
i. RNA polymerase enzyme kinship.
ii. DNA template
iii. RNA primers 38. A segment of DNA molecules comprises of 546
iv. Okazaki segments nuelotides. How many cytosine necleotides would
v. Four types of ribonucleotides triphosphates be present in it if the number of adenine
vi. Divalent metal ions Mg2+ as a cofactor. necleotides is 96 ?
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 Describe the Hershey and Chase experiment. Write the
39. In the medium where, E. coli was growing, lactose conclusion drawn by the scientists after their
was added, which induced the lac operon. Then experiment. OR
why does lac operon shut down some time after How did Alfred Hershey and Martha Chase arrive at the
addition of lactose in the medium? conclusion that DNA is the genetic material?

40. How do Histones acquire positive charge ? 49. (i) State the ‘Central dogma’ as proposed by
Francis Crick. Are there any exceptions to it ?
41. (i) What precaution(s) would you recommend to a Support your answer with a reason and an
patient requiring repeated blood transfusion? example.
(ii) If the advise is not followed by the patient, there is (ii) Explain how the biochemical characterisation
an apprehension that the patient might contract a (nature) of ‘Transforming Principle’ was
disease that would destroy the immune system of determined, which was not defined from Griffith’s
his/her body. experiments.
Explain with the help of schematic diagram only how
the immune system would get affected and 50. (i) Describe the structure and function of a t-RNA
destroyed. molecule. Why is it referred to as an adapter
molecule?
42. (i) What do ‘Y and ‘B’ stand for in ‘YAC’ and ‘BAC’ (ii) Explain the process of splicing of hn-RNA in a
used in Human Genome Project (HGP). Mention eukaryotic cell.
their role in the project.
(ii) Write the percentage of the total human genome 51. (i) What is an operon?
that codes for proteins and the percentage of (ii) Explain how a polycistronic structural gene is
discovered genes whose functions are known as regulated by a common promoter and a
observed during HGP. combination of regulatory genes in a lac-operon.
(iii) Expand ‘SNPs’ identified by scientists in HGP.
52. (i) Describe the series of experiments of F. Griffith.
43. Describe the experiment that helped demonstrate Comment on the significance of the results
the semi-conservative mode of DNA replication. obtained.
(ii) State the contribution of Macleod, McCarty and
44. Explain the mechanism of translation that occurs in Avery.
the ribosomes in a prokaryote.
53. (i) Name the stage in the cell cycle where DNA
45. Name thee e that transcribes hnRNA in eukaryotes. replication occurs.
Explain the steps that the hnRNA undergoes before (ii) Explain the mechanism of DNA replication. Highlight
it is processed into mRNA. the role of enzymes in the process.
(iii) Why is DNA replication said to be semi-
46. Explain the mechanism of DNA replication with the conservative?
help of a replication fock. What role does the
enzyme DNA-ligase play in a DNA replication work? 54. Differentiate between a Cistron and an Exon.

47. Quote the characteristic features of Watson and 55. (a) A DNA segment has a total of 1000
Crick double helical structure. nucleotides, out of which 240 are adenine
OR containing nucleotides. How many pyrimidine
List the salient features of double helix structure of bases this DNA segment possesses?
DNA. (b)Draw a diagrammatic sketch of a portion of DNA
segment to support your answer.
48. Explain in brief, how Hershey-Chase experiment
gave an experimental proof for DNA being a 56. Describe the experiment where Matthew
genetic material? Provide suitable diagram as Meselson and Franklin Stahl used heavy isotope of
necessary. OR nitrogen.
How Hershey-Chase established that DNA is
transferred from virus to bacteria ? 57. (a) State the ‘central dogma’ as proposed by
OR Francis Crick. Are there any exceptions to it?

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 Support your answer with a reason and an
example, 59. Name the source of energy for the replication of
(b) Explain how the biochemical characterization DNA.
(nature) of 'Transforming Principle’ was
determined, which was not defined from Griffith’s 60. Why is RNA more reactive in comparison to DNA?
experiments.
61. Name the transcriptionally active region of
58. (a) Describe the series of experiments of F. chromatin in a nucleus.
Griffith. Comment on the significance of the results
obtained. Heat killed S bacteria
(b) State the contribution of MacLeod, McCarty and
Avery.

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 Sure Shot Questions
Chapter – 06
Evolution
 MCQ (c) Genetic drift
(d) Convergent evolution.
1. Which of the following is used as an atmospheric
pollution indicator?
(a) Lepidoptera (b) Lichens 7. (p q)2  p2  2 pq  q 2  1 represents an
(c) Lycopersicon (d) Lycopodium
equation used in
(a) Population genetics
2. The theory of spontaneous generation stated that
(b) Mendelian genetics
(a) life arose from living forms only
(c) Biometrics
(b) life can arise from both living and non-living
(d) Molecular genetics
(c) life can arise from non-living things only
(d) life arises spontaneously, neither from living
nor from the non-living.
8. Evolution of life shows that life forms had a trend
3. Animal husbandry and plant breeding programmes of moving from
are the examples of (a) Land to water
(a) reverse evolution (b) Dryland to wet land
(b) artificial section (c) Fresh water to sea water
(c) mutation (d) Water to land.
(d) natural selection.

9. Viviparity is considered to be more evolved

4. Palaentological evidences for evolution refer to the because
(a) Development of embryo (a) the young ones are left on their own
(b) Homologous organs (b) the young ones are protected by a thick shell
(c) Fossils (c) the young ones are protected inside the
(d) Analogous organs. mother's body and are looked after they are born
leading to more chances of survival
(d) the embryo takes a long time to develop.

5. The bones of forelimbs of whale, bat, cheetah and

man are similar in structure, because
(a) one organism has given rise to another 10. Fossils are generally found in
(b) they share a common ancestor (a) Sedimentary rocks
(c) they perform the same function (b) Igneous rocks
(d) they have biochemical similarities. (c) Metamorphic rocks
(d) Any type of rock.

6. Analogous organs arise due to

(a) Divergent evolution 11. For the MN-bond group system, the frequencies of
(b) Artificial selection M and N alleles are 0.7 and 0.3, respectively. The

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 expected frequency of MN – blood group bearing 16. Variations during mutations of meiotic
organisms is likely to be recombinations are
(a) 42% (b) 49% (a) random and directionless
(c) 9% (d) 58% (b) random and directional
(c) random and small
(d) random, small and directional.
12. Which type of selection in industrial melanism
observed in moth, Biston betularia?
(a) Stabilising (b) Directional 17. The theory of evolution supported by the
(c) Disruptive (d) Artificial experiment conducted by Louis Pasteur is
[2020]
(a) spontaneous generation theory
(b) Life comes only from pre – existing life
13. The most accepted line of descent in human (c) Abiogenesis of life
evolution is (d) Big bang theory.
(a) Australopithecus  Ramapithecus  Homo
sapiens  Homo habilis
18. Louis Pasteur demonstrated that
(b) Homo erectus  Homo habilis  Homo sapiens
[2020]
(c) Ramapithecus  Homo habilis  Homo erectus (a) Early life came from outer space
 Homo sapiens (b) Non – living chemicals produced living molecules
(d) Australopithecus  Ramapithecus  Homo (c) Life comes from pre – existing life
erectus  Homo habilis  Homo sapiens. (d) Life originated spontaneously.

19. Evolutionary convergence is development of a

14. Which of the following is an example for link (a) common set of functions in groups of different
species? ancestry
(a) Lobe fish (b) Dodo bird (b) dissimilar set of functions in closely related
groups
(c) Sea weed (d) Chimpanzee
(c) common set of structures in closely related
groups
(d) dissimilar set of functions in unrelated groups.
15. Match the scientists listed under Column ‘A’ with [2022 – 23]
ideas listed under Column ‘B’.

Column A Column B 20. Identify the option that gives the correct type of
A. Darwin (i) Abiogenesis evolution exhibited by the two animals shown,
B. Oparin (ii) Use and living in the same habitat in Australia.
disuse of [2023]
organs
C. Lamarck (iii) Continental
drift theory
D. Wagner (iv) Evolution by
natural
selection (a) convergent evolution
(a) A-(i); B-(iv); C-(ii); D-(iii) (b) Disruptive selection
(b) A-(iv); B-(i); C-(ii); D-(iii) (c) Divergent evolution
(d) Homologous ancestry
(c) A-(ii); B-(iv); C-(iii); D-(i)
(d) A-(iv); B-(iii); C-(ii); D-(i)

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 21. At which stage during evolution did human use b) Both A and R are true but R is not the correct
hides to protect their bodies and buried their explanation of A.
dead? c) A is true but R is false.
(a) Homo habilis (c) Java man d) A is false but R is true.
(b) Neanderthal man (d) Homo erectus

 Assertion Reasoning 26. Assertion (A): Man has opposable thumb in his
hand.
Reason (R): It occurred during evolution.
22. Assertion (A) : Homo sapiens have evolved from
a) Both A and R are true and R is the correct
chimpanzee-like ancestors.
explanation of A.
Reason (R) : There is no difference between the
b) Both A and R are true but R is not the correct
two in the amino acid sequence of the protein
explanation of A.
Cytochrome-C.
c) A is true but R is false.
a) Both A and R are true and R is the correct
d) A is false but R is true.
explanation of A
.b) Both A and R are true but R is not the correct
explanation of A.
27. Assertion: These biochemical similarities point to
c)A is true but R is false.
the same shared ancestry as structural Reason:
d)A is false but R is true.
Similarities in proteins and genes performing a
given function among diverse ancestry.
a) Assertion and reason both are correct
statements and reason is correct explanation for
23. Assertion (A) : Homo sapiens have evolved from
assertion.
chimpanzee-like ancestors.
b) Assertion and reason both are correct
Reason (R) : There is no difference between the
statements but reason is not correct explanation
two in the amino acid sequence of the protein
for assertion.
Cytochrome-C.
c)Assertion is correct statement but reason is
a) Both A and R are true and R is the correct
wrong statement.
explanation of A
d)Assertion is wrong statement but reason is
.b) Both A and R are true but R is not the correct
correct statement.
explanation of A.
c)A is true but R is false.
d)A is false but R is true.
28. Assertion (A): Cro-magnon man has more
intelligence than the man of present time.
Reason ®: He is regarded as most recent ancestor
24. Assertion (A): First time Darwin used the phrase
of today’s man.
survival of the fittest.
a). Both A and R are true and R is the correct
Reason (R): The survival of the fittest is the result
explanation of A.
of natural selection.
b) Both A and R are true but R is not the correct
a) Both A and R are true and R is the correct
explanation of A.
explanation of A.
c) A is true but R is false.
b) Both A and R are true but R is not the correct
d) A is false but R is true.
explanation of A.
c) A is true but R is false.
d) A is false but R is true.
 Case Study

25. Assertion (A): The peking man has the knowledge 29. Read the text carefully and answer the questions:
of fire. The essence of Darwinian theory about evolution
Reason (R): The tools made by them was very is natural selection. The rate of appearance of
simple. new forms is linked to the life cycle or the life
a) Both A and R are true and R is the correct span. Microbes that divide fast have the ability to
explanation of A multiply and become millions of individuals within

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 hours. A colony of bacteria (say A) growing on a (b) How natural selection is invariably connected
given medium has built in variation in terms of with speciation.
ability to utilize a feed component. A change in (c) Few bacteria have exposure to new conditions,
the medium composition would bring out only what is the probability of natural selection?
that part of the population (say B) that can survive (d) Is adaptive abilities inherited or not?
under the new conditions. In due course of time
this variant population outgrows the others and  Questions
appears as new species. This would happen within
days. For the same thing to happen in a fish or
fowl would take millions of years as life spans of 31. How is the study of fossils an evidence of
these animals are in years. Here we say that evolution of life forms which have taken place on
fitness of ‘B’ is better than that of ‘A’ under the the earth Explain giving two reasons.
new conditions. Nature selects for fitness. Fitness (2020)
is based upon characteristics which are inherited.
Hence there must be a genetic basis for getting
selected and evolve. Another way of saying the 32. Wings of birds and wings of butterflies contribute
same thing is that some organisms ‘are better to locomotion. Explain the type of evolution such
adapted to survive in a hostile environment. organs are a result of.
Adaptive ability is inherited.

(a) Life span is a factor of natural selection, justify. 33. Explain how natural selection operates in nature
(b) How natural selection is invariably connected by taking an example of white winged and dark
with speciation. winged moths of England.
(c) Few bacteria have exposure to new conditions,
what is the probability of natural selection?
(d) Is adaptive abilities inherited or not?
34. Write about the ancestry and evolution of bat,
horse and human on the basis of a comparative
30. Read the text carefully and answer the questions: study of their forelimbs. What are these limbs
The essence of Darwinian theory about evolution categorised as?
is natural selection. The rate of appearance of
new forms is linked to the life cycle or the life
span. Microbes that divide fast have the ability to 35. Analogous organs are a result of convergent
multiply and become millions of individuals within evolution. Justify with the help of suitable
hours. A colony of bacteria (say A) growing on a example for each.
given medium has built in variation in terms of
ability to utilize a feed component. A change in
the medium composition would bring out only 36. (a) Differentiate between analogous and
that part of the population (say B) that can survive homologous structures.
under the new conditions. In due course of time (b) Select and write analogous structures from the
this variant population outgrows the others and list given below:
appears as new species. This would happen within (i) Wings of butterfly and birds
days. For the same thing to happen in a fish or (ii) Vertebrate hearts
fowl would take millions of years as life spans of (i) Tendrils of Bougainvillea and Cucurbita
these animals are in years. Here we say that (ii) Tubers of sweet potato and potato
fitness of ‘B’ is better than that of ‘A’ under the
new conditions. Nature selects for fitness. Fitness 37. Differentiate between homology and analogy.
is based upon characteristics which are inherited. Give one example of each. (2016)
Hence there must be a genetic basis for getting
selected and evolve. Another way of saying the 38. Differentiate between divergent and convergent
same thing is that some organisms ‘are better evolution. Give one example of each.
adapted to survive in a hostile environment.
Adaptive ability is inherited. 39. Explain convergent evolution with the help of two
examples.
(a) Life span is a factor of natural selection, justify.
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40. What are analogous structures? How are they 50. Differentiate between homology and analogy. Give
different from homologous structures? Provide one example of each.
one example for each. 51. (a) Describe Hardy-Weinberg Principle.
. (b) List any four factors which affect genetic
equilibrium.
41. How did industrialisation play a role in natural (c) Describe founder effect.
selection of light and dark coloured moth in
England? 52. Industrial melanism in England after 1850 is an
excellent example of Natural selection. Explain
42. How does the study of fossils support evolution? how? [2023]
Explain.
53. Giving three reasons, write how Hardy-Weinberg
43. (a) How did Darwin explain adaptive radiation? equilibrium can be affected.
(b) Give another example exhibiting adaptive
radiation. 54. (a) How does the Hardy-Weinberg equation
explain genetic equilibrium?
44. Explain adaptive radiation with the help of a (b) Describe how this equilibrium is disturbed that
suitable example. may lead to founder effect.

45. What is adaptive radiation? When can adaptive 55. Analogous organs are a result of convergent
radiation be referred to as convergent evolution? evolution. Justify with the help of suitable example for
Give an example. each.

46. Explain the interpretation of Charles Darwin when 56. How does the process of natural selection
he observed a variety of small black birds on affect Hardy-Weinberg equilibrium? Explain. List the
Galapagos islands. other four factors that disturb the equilibrium.

47. (a) Explain adaptive radiation with the help of a 57. (a) Rearrange the following in the correct order of
suitable example. their appearance on earth between two million
(b) Cite an example where more than one adaptive years and 40,000 years back. Neanderthals,
radiation have occurred in an isolated Australopithecus, Homo erectus and Homo habilis.
geographical area. Name the type of a evolution (b) Which one of the above
your example depict and state why it is so named. (i) had the largest brain size
(ii) ate fruits?
48. . Hardy-Weinberg principle is stated in the
following algebraic equation: 58. Charles Darwin during his famous sea voyage
p2 + 2pq + q2 = l around the world in a ship (H.M.S. Beagle),
(a) State what do 'p' and 'q' denote in the concluded that there has been gradual evolution of
equation. life.
(b) State Hardy-Weinberg principle as indicated in Answer the following questions:
the equation. (a) What is his theory known as? Explain the salient
(c) What would you interpret if the value of 1 in features of his theory,
the equation gets deviated? (b) Name a scientist who arrived at a similar
conclusion as that of Charles Darwin.
[2019]
49. + 2pq + = 1. Explain the algebraic equation on the 59. Write the characteristics of Ramapithecus,
basis of Hardy Weinberg's principle. Dryopithecus and Neanderthal man.

60. Mention any three characteristics of Neanderthal

man that lived in near East and Central Asia.

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 Sure Shot Questions
Chapter – 07
Human Health and Diseases
6. The genes causing cancer are
 MCQ (a) Structural genes
(b) Expressor genes
1. The term 'Health' Is defined in many ways. The (c) Oncogenes
most accurate definition of the health would be (d) Regulatory genes.
(a) health is the state of body and mind in a balanced
condition
(b) health is the reflection of a smiling face 7. In malignant tumors, the cells proliferate, grow
(c) health is a state of complete physical, mental and rapidly and move to other parts of the body to
social well-being form new tumors. This stage of disease is called
(d) health is the symbol of economic prosperity. (a) metagenesis (b) metastasis
(c) teratogenesis (d) mitosis.

2. The organisms which cause disease in plants and

animals are called 8. When an apparently healthy person is diagnosed
(a) pathogens (b) vectors as unhealthy by a psychiatrist, the reason could be
(c) insects (d) worms. that
(a) the patient was not efficient at his work
(b) the patient was not economically prosperous
3. The chemical test that is used for diagnosis of (c) the patient shows behavioural and social malad
typhoid is justment
(a) ELISA Test (b) ESR Test (d) he does not take interest in sports.
(c) PCR Test (d) Widal test.

9. Which of the following are the reason(s) for

4. The sporozoites that cause infection, when a rheumatoid arthritis? Choose the correct option.
female Anopheles mosquito bites a person, are
formed in (i) The ability to differentiate pathogens or foreign
(a) liver of the person (b) RBCs of mosquito molecules from self cells increases.
(c) salivary glands of mosquito (ii) Body attacks self cells.
(d) intestine of mosquito. (iii) More antibodies are produced in the body.
(iv)The ability to differentiate pathogens or foreign
5. The disease chikungunya is transmitted by molecules from self cells is lost.
(a) House flies (a) (i) and (ii) (b) (ii) and (iv)
(b) Aedes mosquitoes
(c) Cockroach (c) (iii) and (iv) (d) (i) and (iii)
(d) Female Anopheles.

10. 'Smack' is a drug obtained from the

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 (a) More prone to malaria
(a) latex of Papaver somniferum (b) More prone to typhoid
(b) leaves of Cannabis saliva (c) Less prone to malaria
(c) flowers of Datura (d) Less prone to typhoid.
(d) fruits of Erythroxylum coca.

17. Select the pathogen mismatched with the

11. The substance produced by a cell in viral infection symptoms of disease caused by it from the list
that can protect other cells from further infection given below: [2023]
is (a) Entamoeba histolytica: Constipation, abdominal
pain.
(a) serotonin (b) colostrum
(b) Epidermophytoon: Dry scaly lesions on nail.
(c) interferon (d) histamine. (c) Wuchereria bancrofti: Chronic inflammation of
lymphatic vessels of lower limb.
(d) Haemophilus influenzae: Blockage of the intestinal
passage.
12. Transplantation of tissues/organs to save certain
patients often fails due to rejection of such
tissues/organs by the patient. Which type of
immune response is responsible for such 18.Interferons are most effective in making non-
rejections? infected cells resistant against the spread of which
(a) Auto-immune response of the following diseases in humans?
(b) Humoral immune response [2022 – 23]
(a) Ascariasis (b) Ringworm
(c) Physiological immune response
(c) Amoebiasis (d) AIDS
(d) Cell-mediated immune response

19.Select the options which is/are incorrect

13. Which of the following is not a lymphoid tissue?
statement(s) with respect to T – lymphocytes in
the human body.
(a) Spleen (b) Tonsils
(c) Pancreas (d) Thymus (i) They are a type of white blood cells.
(ii) They are produced in bone marrow.
(iii) They remain active at all times in the body.
(iv)They mature in the bone marrow.
14. Which of the following glands is large sized at (a) (i) and (iv) only (b) (iii) only
birth but reduces in size with ageing? (c) (iv) only (d) (iii) and (iv) only
(a) Pineal (b) Pituitary [2023]
(c) Thymus (d) Thyroid

20.The decrease in the T-lymphocytes count in human

blood will result in
15. One of the following is not the causal organism for
ringworm. (a) decrease in antigens
(a) Microsporum (b) decrease in antibodies
(b) Trichophyton (c) increase in antibodies
(d) increase in antigens.
(c) Epidermophyton
[2023]
(d) Macrosporum
21.The principle of vaccination is based on the
property of
(a) specificity
16. A person with sickle cell anaemia is

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(b) diversity
(c) memory
(d) discrimination between self and non-self.
26. Assertion: Alcoholics may show deficiency
 Assertion- Reasoning symptoms of Wemicke’s and Korsakoffs
syndromes.
Reason: Alcohol acts as depressant.
22. Assertion: Breast-feeding is advised by the doctor
as it is essential for the new borns.
Reason: Colostrum secreted by the mother during
initial days of lactation has abundant antibodies
27.Assertion: Cancer cells are virtually immortal until
containing IgE and IgG.
the body in which they reside dies.
(a) Both A and R are true and R is the correct
Reason: Cancer is caused by damage to genes
explanation of A.
regulating the cell division cycle.
(b) Both A and R are true and R is not the correct
explanation of A.
(c) A is true but R is false,
(d) A is false but R is true.
28.Assertion: Benign tumour are called neoplastic
cells.
Reason: Malignant tumour remain in place to form
a compact mass by a process known as metastasis.
Directions: In the following questions, a statement of
assertion is followed by a statement of reason
Mark the correct choice as:
(a) If both assertion and reason are true and reason is
the correct explanation of assertion.  Case Study
(b) If both assertion and reason are true but reason is
not the correct explanation of assertion. 29. Read the text carefully and answer the questions:
(c) If assertion is true but reason is false. Riya studies in II standard in a government school.
(d) If both assertion and reason are false. She belongs to a backward family and her parents
did not get her properly vaccinated according to
23.Assertion: All immunoglobin molecules have a immunization programme. Once while playing in
basic structure composed of four polypeptide school playground she fell down due to weakness
chains. and developed high fever, headache and stiffness
Reason: The polypeptide chains consists of two in her neck. Identify the illness she could be
identical heavy and light chain connected by suffering from and answer the following questions.
disulphide bonds.
(a) The microbe responsible for Riyas illness could be
a) Vibrio cholerae
b) Mycobacterium
24.Assertion: Inspite of exposure to large number of c) Enterovirus
infectious agents, humans are resistive to d) Plasmodium
diseases.Reason: Humans are able to defend
against most of the foreign agents due to the (b) Which vaccine, if administered earlier, would have
ability to fight disease causing organisms. saved Riya from the illness she unfortunately
contracted?
a) MMR vaccine b) Salk vaccine
c) BCG vaccine d) Varicella vaccine
25.Assertion: Cocaine has a potent stimulating action
on central nervous system, producing a sense of (c) The disease that Riya has contracted spreads
euphoria and increased energy. through
Reason: Injecting the microbes intentionally during a) Faecal oral route
immunisation or infectious organisms gaining b) Direct contact with the infected person.
access into body during natural infection induces c) Bite of an infected mosquito
active immunity. d) Bite of an infected dog

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 response in the human body. How do these cells
(d) Riya can spread her illness to other children respond when a pathogen enters the body?
through
a) Coughing and sneezing in open 36. How does a vaccine for a particular disease
b) Her faeces immunise the body against that disease?
c) Direct contact
d) Vectors 37. A patient showed symptoms of constipation,
abdominal pain and stools with excess mucous
(e) Assertion (A): Polio produces inflammation of the and blood clots. Name the disease and its
nervous system. pathogen. Where do these pathogens live in the
Reason (R): Stiffness of the neck, paralysis of victim’s body? Name the mechanical carrier that
particular skeletal muscle is an important symptom transmits the parasite.
of polio.
a) Both A and R are true and R is the correct 38. Write the source and the effect on the human
explanation of A. body of the following drugs:
b) Both A and R are true but R is not the correct (i) Morphine
explanation of A. (ii) Cocaine
c) A is true but R is false. (iii) Marijuana
d) A is false but R is true.
39. (i) Name the source plant of heroin drug. How is it
obtained from the plant?
30. Read the text carefully and answer the questions: (ii) Write the effects of heroin on the human body.
Siddharth is a chain smoker, he got into this habit
in early adolescent due to peer pressure and 40. Principle of vaccination is based on the property
gradually got addicted in this habit. It is now 20 of “memory” of the immune system. Taking one
yrs., he is into the habit of smoking since few suitable example, justify the statement.
months he is experiencing pain in chest, shortness
of breathing, wheezing and chronic cough with 41. (a) It is generally observed that the children who
phlegm. He sought advice of medical practitioner had suffered from chicken-pox in their childhood
who diagnosed him with lung cancer. may not contract the same disease in their
adulthood. Explain giving reasons the basis of
(a) Enumerate the two properties of cancer cells. such an immunity in an individual. Name this kind
(b) How is lung cancer diagnosed? of immunity,
(c) What do you mean by carcinogen? Give some (b) What are interferons? Mention their role.
examples. [Al 2016]
(d) Differentiate between two different types of 42. Name the causative organism of the disease
tumours. amoebiasis. List three symptoms of the disease.

 Questions 43. Name the pathogen responsible for typhoid.

31. Compare the symptoms of ascariasis, amoebiasis What are the symptoms of typhoid?
and elephantiasis. OR
Name the causative agent of the typhoid in humans.
32. What is Innate Immunity? What are the barriers in Name the test administered to confirm the disease.
it? What is cytokine barrier? How does the pathogen gain an entry into the human
body? Write the diagnostic symptoms and mention
33. What makes some viruses cause cancer in humans the body organs that get affected in severe cases.
? How does benign tumour turn malignant? How
does the latter harm the human body? 44. List the symptoms of Ascariasis. How a healthy
person acquires this infection?
34. How are cancerous cells different from normal
45. Name the parasite that causes filariasis in human.
cells?
Mention its two diagnostic symptoms. How is this
disease transmitted to others?
35. Name the different types of cells that are
responsible for producing the acquired immune

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46. Name the plant source of ganja. How does it (i) Mention one symptom to diagnose the sickness.
affect the body of the abuser? (ii) What caused the sickness?
(iii) How could she recover by herself after some
47. Name an opioid drug and its source plant. How time?
does the drug affect the human body?
54. Highlight the structural importance of an antibody
48. Name the cells that act as HIV factory in human molecule with a diagram. Name the four types of
when infected by HIV. Explain the events that antibodies found to give a humoral immune
occur in the infected cells. response, mentioning the functions of two of them
you have studied.
49. Cancer is one of the most dreaded diseases of 55. (a) Differentiate between active and passive
humans. Explain ‘Contact inhibition’ and immunity.
‘Metastasis’ with respect to disease. Name the (b) Comment on the role of vaccination and
groups of genes which have been identified in the immuzation in keeping human population
normal cells that could lead to cancer and how healthy.
they do so? Name any two techniques which are
useful to detect cancers of internal organs. Why 56. Differentiate between Innate Immunity and
are cancer patients often given alpha interferon Acquired Immunity.
as part of the treatment?
57. A person is suffering from a high – grade fever.
50. Name any two organisms that are responsible for Which symptoms will help to identify if he/she is
causing ring worm in humans. Mention two suffering from typhoid, pneumonia or malaria?
diagnostic symptoms. Name the specific parts of
the human body where these organisms thrive 58. Distinguish between Malignant tumour and Benign
and explain why? tumour.
OR
51. (a) Explain the roles of (i) primary, and (ii) Differentiate between benign tumour and malignant
secondary lymphoid organs that are responsible tumour.
for developing defence to combat the action of
pathogens/foreign antigens which enter our body. 59. (a) What precaution(s) would you recommend to a
(b) Doctors generally advise not to undergo surgery of patient requiring repeated blood transfusion?
tonsils. Why? (b) If the advise is not followed by the patient, there is
[Term II, 2021 – 22] an apprehension that the patient might contract a
52. ‘Prevention is better than cure’ is an apt slogan to disease that would destroy the immune system of
safeguard adolescents from drug abuse. List any his/her body. Explain with the help of schematic
six steps that could be taken in this regard? diagram only how the immune system would get
53. During a school trip to ‘Rohtang Pass’, one of your affected and destroyed.
classmate suddenly developed ‘altitude sickness’.
But, she recovered after sometime.

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 Sure Shot Questions
Chapter – 08
Microbes in Human Welfare
(ii) Cyclosporin A (B) Removal of clots
from blood vessels
 MCQ
(iii) Streptokinase (C) Lowering of blood
1. The vitamin whose content increases following
cholesterol
the conversion of milk into curd by lactic acid
(iv) Lipase (D) Immuno-
bacteria is suppressive agent
(a) vitamin C (b) vitamin D Choose the correct match.
(c) vitamin B12 (d) vitamin E.
(a) i  ( B),ii (C ),iii ( A),iv ( D)
2. Wastewater treatment generates a large quantity (b) i  ( D),ii ( B),iii ( A),iv (C)
of sludge, which can be treated by (c) i  ( D),ii ( A),iii ( B),iv (C)
(a) Anaerobic digesters
(d) i  (C ),ii ( D),iii ( B),iv ( A)
(b) Floc
(c) Chemicals
(d) Oxidation pond.
5. The primary treatment of wastewater involves the
removal of
(a) dissolved impurities
3. Match the following list of bacteria and their
(b) stable particles
commercially important products.
(c) toxic substances
Bacterium Product (d) harmful bacteria.
(i) Aspergillus niger (A) Lactic acid
(ii) Acetobacter aceti (B) Butyric acid
(iii) Clostridium (C) Acetic acid
butylicum 6. BOD of wastewater is estimated by measuring the
(iv) Lactobacillus (D) Citric acid amount of
Choose the correct match. (a) total organic matter
(b) biodegradable organic matter
(a) i  (B),ii (C),iii (D),iv (A) (c) oxygen evolution
(b) i  (B),ii ( D),iii (C),iv (A) (d) oxygen consumption.
(c) i  ( D),ii (C),iii ( B),iv (A)
(d) i  ( D),ii ( A),iii (C),iv ( B)
7. Which one of the following alcoholic drinks is
produced without distillation?
(a) Wine (b) Whisky
4. Match the following list of bioactive substances
(c) Rum (d) Brandy
and their roles.

Bioactive Role
substance 8. The technology of biogas production from cow
(i) Statin (A) Removal of oil dung was developed in India largely due to the
stains efforts of

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 (a) Gas Authority of India (d) a fungus that releases a lot of gases during its
(b) Oil and Natural Gas Commission metabolic activities.
(c) Indian Agricultural Research Institute and 14. The residue left after methane production from
Khadi & Village Industries Commission cattle dung is
(d) Indian Oil Corporation. (a) Burnt
(b) Buried in land fills
(c) Used as manure
9. The free-living fungus Trichoderma can be used (d) Used in civil construction.
for
(a) killing insects
(b) biological control of plant diseases 15. Methanogens do not produce
(c) controlling butterfly caterpillars (a) oxygen (b) methane
(d) producing antibiotics. (c) hydrogen sulphide (d) carbon dioxide

10. What would happen if oxygen availability to 16. Activated sludge should have the ability to settle
activated sludge floes is reduced? quickly so that it can
(a) It will slow down the rate of degradation of (a) be rapidly pumped back from sedimentation
organic matter, tank to aeration tank
(b) The center of floes will become anoxic, which (b) absorb pathogenic bacteria present in
would cause death of bacteria and eventually wastewater while sinking to the bottom of the
breakage of floes. settling tank
(c) Flocs would increase in size as anaerobic (c) be discarded and anaerobically digested
bacteria would grow around flocs. (d) absorb colloidal organic matter.
(d) Protozoa would grow in large numbers.

17. Match the items in column ‘A’ and column ‘B’ and
11. Mycorrhiza does not help the host plant in choose correct answer.
(a) enhancing its phosphorus uptake capacity
(b) increasing its tolerance to drought Column A Column B
(i) Lady bird (A) Methanobacterium
(c) enhancing its resistance to root pathogens
(ii) Mycorrhiza (B) Trichoderma
(d) increasing its resistance to insects.
(iii) Biological (C) Aphids
control
(iv) Biogas (D) Glomus
12. Which one of the following is not a nitrogen – The correct answer is
fixing organism?
(a) (i)  B,(ii)  D,(iii)  C,(iv)  A
(a) Anabaena (b) Nostoc
(c) Azotobacter (d) Pseudomonas (b) (i)  C,(ii)  D,(iii)  B,(iv)  A
(c) (i)  D,(ii)  A,(iii)  B,(iv)  C
(d) (i)  C,(ii)  B,(iii)  A,(iv)  D
13. Big holes in Swiss cheese are made by a
(a) a machine
(b) a bacterium that produces methane gas 18. Large holes in “Swiss Cheese” are due to
(c) a bacterium producing a large amount of [2020]
carbon dioxide (a) Propionibacterium shermanii
(b) Saccharomyces cerevisiae

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 (c) Penicillium chrysogenum (a) Both assertion and reason are true, and reason
(d) Acetobacter aceti. is the correct explanation of assertion,
(b) Both assertion and reason are true, but reason
is not the correct explanation of assertion,
(c) Assertion is true but reason is false, (d) Both
19. The bioactive molecule used as an assertion and reason are false. [2020 – 21]
immunosuppressive agent during organ
transplant is [2020]
Directions: In the following questions, a
(a) tetracyclin (b) cyclosporin A statement of assertion is followed by a statement
(c) statin (d) streptomycin. of reason Mark the correct choice as:

(a) If both assertion and reason are true and

reason is the correct explanation of assertion.
20. Which of the following water samples in the table (b) If both assertion and reason are true but
given below, will have a higher concentration of reason is not the correct explanation of assertion.
organic matter? [2022 – 23] (c) If assertion is true but reason is false.
(d) If both assertion and reason are false.
Level of Pollution Value of BOD
(a) High High 24. Assertion: Toddy becomes unpalatable after 24
(b) Low Low hours.
(c) Low High Reason: The fermentation of toddy is continued
(d) High Low by naturally occurring yeasts.

25. Assertion: The use of fertilizers greatly enhances

21. Which one of the following fixes the atmospheric crop productivity.
nitrogen but is not an autotroph? Reason: Irrigation is very important in increasing
[2023] crop productivity.
(a) Oscillatoria (b) Rhizobium
(c) Anabaena (d) Nostoc

26. Assertion: Bio fertilizers are preferred to chemical

fertilizers.
22. Some cyanobacteria in aquatic and terrestrial Reason: Chemical fertilizers are generally more
environment that enrich the soil by fixing expensive and hazardous to the environment.
atmospheric nitrogen are [2020C]
(a) Rhizobium and Azotobacter
(b) Azospirillum and Glomus
(c) Anabaena and Nostoc 27. Assertion: Leguminous plants are best preferred
(d) Azospirillum and Azotobacter in rotation of crops.
Reason: They have root nodules, which have
nitrogen-fixing bacteria Clostridium.

 Assertion Reasoning
23. Assertion: Releasing dragonflies in areas where 28. Assertion: Disadvantages of synthetic pesticides
there is an outbreak of malarial diseases can be can be overcome by the use of natural or
an environment friendly method of control. biopesticides.
Reason: Dragonflies are dominant species-and will Reason: Biopesticides are harmless agents which
not allow mosquitoes to reproduce, are used to control weeds and pest without
causing any damage.

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 (b) Dragonfly nymphs selectively eat mosquito
29. Assertion: Biogas is used as fuel for cooking and larvae
lighting. (c) They help to decrease the probability of
Reason: It is considered as eco-friendly and diseases spread by vectors
pollution free source of energy. (d) Dragonfly do not cause any harm to
beneficial species.

(iv) The most effective stages in the life cycle of

 Case study dragonfly that eradicate mosquitoes are

(a) Larvae and adult

30. Read the following and answer any four questions
(b) Caterpillar and adult
from 4(i) to 4(v) given below;
(c) Nymph and adult
Ecological Indicators
(d) Pupa and adult.
The presence of dragon flies can reveal changes
(v) Assertion: Releasing dragonflies in areas
in the water ecosystems more quickly than
where there is an outbreak of malarial
studying other animals or plants. In fact, from
diseases can be an environment friendly
the nymph to the adult stage, the dragonfly has
method of control.
a significant, positive ecological impact.
Reason: Dragonflies are dominant species-
Dragonfly eggs are laid and hatched in or near
and will not allow mosquitoes to reproduce,
water, so their lives impact both water and land
ecosystems. Once hatched, dragonfly nymphs
(a) Both assertion and reason are true, and reason is
can breathe underwater which enables them to
the correct explanation of assertion,
eat mosquito larvae, other aquatic insects and
(b) Both assertion and reason are true, but reason is
worms, and even small aquatic vertebrates like
not the correct explanation of assertion,
tadpoles and small fish and in the air. Adult
(c) Assertion is true but reason is false,
dragonflies capture and eat adult mosquitoes.
(d) Both assertion and reason are false.
Community wide mosquito control programs
that spray insecticides to kill adult mosquitoes
also kill dragonflies. 31. Read the text carefully and answer the questions:

We use microbes or products which are derived from

(i) The approach to biological control includes
them every day. A common example is the production
(a) Import and release of an insert pest to a new
of curd from
area to provide hosts for natural enemies
milk. Micro - organisms such as Lactobacillus and
(b) Import and release of natural enemies from
others commonly called lactic acid bacteria (LAB)
the native home of an alien insect pest that
grow in milk and
has invaded a new area
convert it to curd. The dough, which is used for
(c) Preservation of natural enemies (predators
making foods such as dosa and idli is also fermented
and parasitoids) that are already established
by bacteria. A number of traditional drinks and foods
in an area
are also made by fermentation by the microbes.
(d) Use of insecticides to reduce alien insect
‘Toddy’, a traditional drink
pests to establish new equilibrium position.
of some parts of southern India is made by fermenting
sap from palms. The ‘Roquefort cheese’ is ripened by
(ii) Two diseases less likely to occur in a region with
growing
plenty of dragonflies are_____
specific fungi on them, which gives them a particular
flavour. Different varieties of cheese are known by
(a) Yellow fever and amoebic dysentery
their characteristic
(b) Malaria and yellow fever
texture, flavour and taste, the specificity coming from
(c) Anthrax and typhoid
the microbes used.
(d) Cholera and typhoid
(a) Which of the following organisms is used in the
production of beverages?
(iii) Dragonflies indicate positive ecological impact
a) Aspergillus niger
as
b) Clostridium butylicum
(a) The presence of dragonflies indicates
c) Penicillium notatum
polluted water
d) Saccharomyces cerevisiae
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 37. Find out the name of the microbes from
(b) Microbes are present in which Cyclosporine A (an immunosuppressive drug)
a) Soil and Statins (blood cholesterol lowering agents) are
b) Polluted water obtained.
c) All of these OR
d) Thermal vents Name the source of cyclosporin-A. How does this
bioactive molecule function in our body?
(c) Saccharomyces cerevisiae is used primarily for
a) Baking b) Bleaching 38. Name the bacterium responsible for the large
c) Biofuel d) None of these holes seen in ‘Swiss Cheese’. What are these holes
due to?
(d) The large holes in ’Swiss cheese’ are due to
a) Production of a large amount of CO2 39. How does mycorrhiza act as bio fertiliser ?
b) None of these Explain. Name a genus of a fungus that forms a
c) Due to the presence of water mycorrhizal association with the plants.
d) Production of O2
(e) Assertion (A): Lactic acid bacteria (LAB) grow in 40. Name the enzyme produced by Streptococcus
milk and convert it to curd. bacterium. Explain its importance in medical
Reason (R): It produces acids that coagulate and science.
partially digest the milk proteins.
41. Mention two advantages of adding blue-green
a) Both A and R are true and R is the correct algae to paddy fields.
explanation of A.
b) Both A and R are true but R is not the correct 42. Why is Rhizobium categorised as a symbiotic
explanation of A. bacterium ? How does it act as a bio fertiliser ?
c) A is true but R is false.
d) A is false but R is true. 43. Give the bionomials of two types of yeast and the
commercial bioactive products they help to
 Question produce.
32. State the medicinal value and the bioactive
molecules produced by Penicillium notatum, 44. Write the binomials of two fungi and mention the
Monascus purpureus and Trichoderma products or bioactive molecules they help to
polysporum. produce.

33. State the medicinal value and the bioactive 45. Name the bacterium responsible for the large
molecules produced by Streptococcus, Monascus holes seen in ‘Swiss Cheese’. What are these holes
and Trichoderma. due to?

34. (a) Why are the fruit juices bought from market 46. “Growing spirullina on a large scale is beneficial
clearer as compared to those made at home? both environmentally and nutritionally for
(b) Name the bioactive molecules produced humans.” Justify.
by Trichoderma polysporum and Monascus
purpureus. 47. Name a free-living and a symbiotic bacterium
that serve as biofertiliser. Why are they so called?
35. Secondary treatment of the sewage is also called
biological treatment. Justify this statement and 48. Mention a product of human welfare obtained
explain the process. with the help of each one of the following
microbes:
36. (a) Write the scientific name of methanogen (a) LAB
bacteria. Where are these bacteria generally (b) Saccharomyces cerevisiae
found? Explain their role in biogas production. (c) Propionibacterium shermanii
(b) Name the components of biogas. (d) Aspergillus niger

49. What is Biological Oxygen Demand?

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50. Determination of Biological Oxygen Demand 57. What are ‘flocs’, formed during secondary
(BOD) can help in suggesting the quality of water treatment of sewage?
body. Explain.
58. Write any two places where methanogens can be
51. Mention the importance of microbes found.
Streptococcus, Trichoderma and Monascus in
medical sciences. 59. Explain the process of secondary treatment given to
the primary effluent up to the point it shows
52. Why do farmers prefer biofertilizers to chemical significant change in the level of biological oxygen
fertilizers these days? Explain. How do anabaena demand (BOD) in it. [Al 2015]
and mycorrhiza act as biofertilizers?
60. (i) Give an example of a genus of virus used as
53. Given below is a list of six micro-organisms. State narrow spectrum insecticidal biocontrol agent,
their usefulness to humans. (ii) How does its use serve as an aid in overall integrated
(i) Nucleopolyhedrovirus pest management programme?
(ii) Saccharomyces cerevisiae [2023]
(iii) Monascus purpureus 61. What is STP? Explain the treatment process in brief.
(iv) Trichoderma polysporum OR
(v) Penicillium notatum How is activated sludge formed during sewage
(vi) Propionibacterium sharmanii treatment? This sludge can be used as inoculums or
as a source of biogas. Explain.
54. Give examples to prove that microbes release OR
gases during metabolism. Explain the process of sewage water treatment before it
can be discharged into natural water bodies. Why is
55. (i) How do organic farmers control pests? Give this treatment essential?
two examples. OR
(ii) State the difference in their approach from
that of conventional pest control methods. Name the category of microbes occurring naturally in
sewage and making it less polluted during the
56. What is IPM? Explain the mechanism of Bt in the treatment. Explain different steps involved in
cotton. secondary treatment of sewage

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 Sure Shot Questions
Chapter – 09
Biotechnology: Principles and Processes
(b) cutting of DNA at specific position only
 MCQ (c) prevention of the multiplication of bacteriophage
in bacteria
1. Rising of dough is due to (d) all of the above.

(a) Multiplication of yeast

(b) Production of CO2 6. Which of the following is not required in the
(c) Emulsification preparation of a recombinant DNA molecule?
(d) Hydrolysis of wheat flour starch into sugars.
(a) Restriction endonuclease
(b) DNA ligase
2. An enzyme catalysing the removal of nucleotides (c) DNA fragments
from the ends of DNA is (d) E.coli

(a) endonuclease (b) exonuclease

(c) DNA ligase (d) Hind II. 7. In agarose gel electrophoresis, DNA molecules are
separated on the basis of their

3. The transfer of genetic material from one (a) Charge only

bacterium to another through the mediation of a (b) Size only
vector like virus is termed as (c) Charge to size ratio
(d) All of the above.
(a) transduction (b) conjugation
(c) transformation (d) translation.
8. The most important feature in a plasmid to be
used as a vector is
4. Which of the given statements is correct in the (a) origin of replication (ori)
context of observing DNA separated by agarose gel (b) presence of a selectable marker
electrophoresis? (c) presence of sites for restriction endonuclease
(a) DNA can be seen in visible light, (d) its size.
(b) DNA can be seen without staining in visible light,
(c) Ethidium bromide stained DNA can be seen in
visible light, 9. While isolating DNA from bacteria, which of the
(d) Ethidium bromide stained DNA can be seen under following enzymes is not used?
exposure to UV light. (a) Lysozyme
(b) Ribonuclease
(c) Deoxyribonuclease
5. 'Restriction' in restriction enzyme refers to (d) Protease
(a) cleaving of phosphodiester bond in DNA by the
enzyme
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10.Which of the following has popularised the PCR (c) Extension of primer end on the template DNA
(polymerase chain reactions)? (d) All of the above

(a) Easy availability of DNA template

(b) Availability of synthetic primers 16. A bacterial cell was transformed with a
(c) Availability of cheap deoxyribonucleotides recombinant DNA that was generated using a
(d) Availability of 'thermostable' DNA polymerase human gene. However, the transformed cells did
not produce the desired protein. Reasons could be
(a) human gene may have intron which bacteria
11.An antibiotic resistance gene in a vector usually cannot process
helps in the selection of (b) amino acid codons for humans and bacteria are
(a) competent cells (b) transformed cells different
(c) recombinant cells (d) none of the above. (c) human protein is formed but degraded by bacteria
(d) all of the above.

12. Significance of 'heat shock' method in bacterial

transformation is to facilitate 17. Which of the following should be chosen for best
(a) binding of DNA to the cell wall yield if one were to produce a recombinant protein
(b) uptake of DNA through membrane transport in large amounts?
proteins (a) Laboratory flask of largest capacity
(c) uptake of DNA through transient pores in the (b) A stirred-tank bioreactor without in-lets and out-
bacterial cell wall lets
(d) expression of antibiotic resistance gene. (c) A continuous culture system
(d) Any of the above

13.The role of DNA ligase in the construction of a

recombinant DNA molecule is 18. Who among the following was awarded the Nobel
(a) formation of phosphodiester bond between two Prize for the development of PCR technique?
DNA fragments (a) Herbert Boyer
(b) formation of hydrogen bonds between sticky ends (b) Har Gobind Khorana
of DNA fragments (c) Kary Mullis
(c) ligation of all purine and pyrimidine bases (d) Arthur Kornberg
(d) none of the above.

19. Which of the following statements does not hold

14. Which of the following is not a source of true for restriction enzyme?
restriction endonuclease? (a) It recognises a palindromic nucleotide sequence,
(a) Haemophilus influenzae (b) It is an endonuclease,
(b) Escherichia coli (c) It is isolated from viruses,
(c) Entamoeba coli (d) It produces the same kind of sticky ends in
(d) Bacillus amyloliquifaciens different DNA molecules.

20.In biotechnology experiment, ‘molecular scissors’

15.Which of the following steps are catalysed by Taq used are [2020C]
polymerase in a PCR reaction? (a) plasmid (b) restriction enzymes
(a) Denaturation of template DNA (c) vectors (d) sigma factor.
(b) Annealing of primers to template DNA

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 24.The given schematic illustration shows three steps
21.The given figure shows the structure of a plasmid. ‘P’, ‘Q’ and ‘R’ of the polymerase chain reaction.

A foreign DNA was ligated at BamH1. The

transformants were then grown in a medium
containing antibiotic tetracycline and ampicillin.
Choose the correct observation for the growth of Which of the following statements are correct with
bacterial colonies from the given table. reference to the illustration given above?
[2022 – 23] (i) Step ‘P’ is showing denaturation at low
Medium with Medium with temperature.
tetracycline ampicillin (ii) Step ‘Q’ is a denaturation of DNA strand at high
(a) Growth No growth temperature, followed by annealing.
(b) No growth Growth (iii) Step ‘R’ is an extension of DNA in presence of
(c) No growth No growth thermostable DNA polymerase.
(d) Growth Growth (iv)Step ‘Q’ is extension with two sets of primers.

(a) (i) and (iii) only

22. Given below is the restriction site of a restriction (b) (ii) and (iii) only
endonuclease Pst – I and the cleavage sites on a (c) (ii) only
DNA molecule. (d) (i) only

5' C  T  G  C  A  G 3'

3' G  A  C  G  T  C '5'  Assertion Reason


Choose the option that gives the correct resultant
fragments by the action of the enzyme Pst – I. 25. Assertion: E coli having pBR322 with DNA insert at
Bam HI site cannot grow in medium containing
tetracycline.
Reason: Recognition site for Bam HI is present in tet’’
region of pBR322.
(a) Both assertion and reason are true, and reason is
the correct explanation of assertion,
(b) Both assertion and reason are true, but reason is
not the correct explanation of assertion,
(c) Assertion is true but reason is false,
(d) Both assertion and reason are false.
[2020 – 21]

23. Introduction of an alien DNA into a plant host cell 26. Assertion (A): Synthetic oligo-nucleotide polymers
is achieved by making them are used during annealing in a PCR.
(a) competent with bivalent ions Reason (R): The primers bind to the double stranded
(b) using microinjections DNA at their complementary regions,
(c) using gene gun
(d) using lysozymes and chitinase. (a) Both (A) and (R) are true and (R) is the correct
explanation of (A),
(b) Both (A) and (R) true, but (R) is not the correct
explanation of (A),
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 (c) (A) is true, but (R) is false, (d) (A) is false, but (R) is DNA. Complementary DNA (cDNA) is synthesized on
true. RNA template (usually mRNA) with the help of
reverse transcriptase. Synthetic DNA (sDNA) is
Directions: In the following questions, a statement of synthesized on DNA template or without a template.
assertion is followed by a statement of reason Random DNA are small fragments formed by
Mark the correct choice as: breaking a chromosome of an organism in the
presence of restriction endonucleases.
(a) If both assertion and reason are true and reason is
the correct explanation of assertion.
(b) If both assertion and reason are true but reason is
not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If both assertion and reason are false.

27. Assertion: To diagnose presence of a specific DNA

segment in a mixture, complementary pairing
between nucleotides is exploited.
Reason: DNA probes having radioactive isotopes help
(a) Reverse transcriptase enzyme was discovered by
to detect DNA by autoradiography.
a) Paul Berg
b) Arber and Nathan
28. Assertion: Agrobacterium tumefaciens is popular
c) Cohen and Boyer
in genetic engineering because this bacterium is
d) Temin and Baltimore
associated with the stems of all cereal and pulse
crops.
(b) What would happen if DNA formed by reverse
Reason: A gene incorporated in the bacterial
transcriptase is not treated with the alkali?
chromosomal genome gets automatically
transferred to the crops with which the bacterium
a) C DNA will not be digested
is associated.
b) Hydrogen bonds will not form between base pairs
c) M RNA will not be formed.
29. Assertion: Cry gene expressing crop is resistant to
d) M RNA will not be digested
a group of insects.
Reason: Cry proteins produced from Bacillus
(c) An enzyme that helps in the formation of double -
thuringiensis are toxic to larvae of certain insects.
stranded cDNA is
30. Assertion: To cure SCID, the first clinical gene for
a) DNA polymerase
ADA therapy was given.
b) Helicase
Reason: Using retroviral vector the normal gene was
c) Ligase
delivered into the patient's cells.
d) DNA synthetase
31. Assertion: A crop expressing a cry gene is usually
(d) DNA polymerase can be obtained from
resistant to a group of insects.
Reason: Cry proteins produced from Bacillus
a) Retrovirus
thuringiensis are toxic to larvae of certain insects.
b) Thermus aquaticus
c) Agrobacterium
d) Tobacco mosaic virus
 Case study
(e) DNA synthesised without a template is referred to
32. Read the text carefully and answer the questions: as
The DNA, which is transferred from one organism into a) Random DNA
another by joining it with the vehicle DNA is called b) Z - DNA
passenger or foreign DNA. Generally, three types of c) Complementary DNA
passenger DNAs are used. These are complementary d) Synthetic DNA
DNA (cDNA), synthetic DNA (sDNA) and random

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33. Read the text carefully and answer the questions: does restriction endonuclease act on the DNA
Cloning Read the text carefully and answer the molecule?
questions: Cloning vectors are DNA molecules into
which foreign DNA can be inserted. Typically, 43. Why do lepidoplerans die when they feed on Bt
scientists adapt naturally occurring structures that cotton plant ? Explain how does it happen.
can replicate independent of chromosomal DNA.
For example, plasmids are circular, double -
stranded DNA molecules that can be found in
several numbers within a single bacterial cell. 44. During a fire in an auditorium a large number of
Observe the given diagram and answer the assembled guests got burnt beyond recognition.
questions that follow Suggest and describe a modern technique that
can help hand over the dead to their relatives.

45. Suggest and describe a technique to obtain

multiple copies of a gene of interest in vitro.

46. What are the important steps of recombinant

DNA technology?

(a) What does BR stand for in pBR322. 47. How are the following used in biotechnology:
(b) What is the function of rop gene? (i) Plasmid DNA
(c) What is the role of parts labelled a, d and b. (ii) Recognition sequence
(d) Antibiotic resistance genes are commonly used (iii) Gel electrophoresis
markers.
Why? 48. Distinguish between endonuclease and
 Questions exonucleases.
34. State the role of DNA ligase in biotechnology.
49. Non-viral and non-vector methods are sometimes
35. Why is ‘Plasmid’ an important tool in used to transfer genes or alien DNA into a plant
biotechnology experiments? cell. Explain one such method used in genetic
engineering.
36. Why is it not possible for an alien DNA to become
part of a chromosome anywhere along its length 50. Name any two natural cloning vectors. Give
and replicate normally? reasons that make them act as cloning vectors.
Write the two characteristics the engineered
37. Explain the work carried out by Cohen and Boyer vectors are made to possess.
that contributed immensely in biotechnology.
51. (a) Write the palindromic nucleotide sequence
38. Write the role of ‘Ori’ and ‘restriction’ site in a 𝐸𝑐𝑜𝑅𝐼 recognises.
cloning vector 𝑝𝐵𝑅322. (b) Draw the vector DNA and a foreign DNA showing
the sites where 𝐸𝑐𝑜𝑅𝐼 has acted to form the sticky
39. How is the action of normal endonuclease ends.
enzymes different from that of restriction endo- (c) Name the enzymes that help in forming
nuclease? recombinant DNA.
52. Name and describe the technique that helps in
40. Explain the process of gel-electrophoresis separating the DNA fragments formed by the use
technique. of restriction endonuclease.

41. Describe the formation of recombinant DNA by 53. Draw pBR322 cloning vector. Label ′𝑜𝑟𝑖′, ′𝑟𝑜𝑝′
the action of 𝐸𝑐𝑜𝑅𝐼. and any one antibiotic resistance site on it and
state their functions.
42. Illustrate the recognition sequence of EcoRI and
mention what such sequences are called? How 54. Causative agents of HIV-AIDS and COVID-19
belong to the same group of viruses. To diagnose
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 and amplify the genetic material for further study 58. A cell free method of amplifying DNA first
of COVID-19 virus, ′𝑅𝑇 − 𝑃𝐶𝑅′ test is carried out. developed in the mid 1980's revolutionized the
(a) What does ′𝑅𝑇 − 𝑃𝐶𝑅′ stand for? field of biotechnology. Name the method and
(b) Explain the various steps of PCR technique. explain the basic steps of the technique involved.
59. Name the enzymes that are used for the isolation
of DNA from bacterial and fungal cells for
55. Write the two components of the first artificial recombinant DNA technology.
recombinant DNA molecule constructed by Cohen
and Boyer. 60. 'Insertional inactivation’ is a method to detect
56. What is EcoRI? How does EcoRI differ from an recombinant DNA. Explain the method.
exonuclease?
61. (a) Describe the different steps in one complete
57. Explain palindromic nucleotide sequence with the cycle of PCR.
help of a suitable example. (b) State the purpose of such an amplified DNA
sequence.

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 Sure Shot Questions
Chapter – 10
Biotechnology and its Applications
 MCQ 7. The site of production of ADA in the body is

1. Bt cotton is not (a) erythrocytes (b) lymphocytes

(a) a GM plant (c) blood plasma (d) osteocytes.
(b) insect resistant
(c) a bacterial gene expressing system 8. A protoxin is
(d) resistant to all pesticides. (a) A primitive toxin
(b) A denatured toxin
2. C-peptide of human insulin is (c) Toxin produced by protozoa
(a) a part of mature insulin molecule (d) Inactive toxin.
(b) responsible for formation of disulphide bridges
(c) removed during maturation of pro-insulin to
insulin 9. Pathophysiology is the
(d) responsible for its biological activity. (a) study of physiology of pathogen
(b) study of normal physiology of host
(c) study of altered physiology of host
3. GEAC stands for (d) none of the above.
(a) Genome Engineering Action Committee
(b) Ground Environment Action Committee
(c) Genetic Engineering Approval Committee 10. The trigger for activation of toxin of Bacillus
(d) Genetic and Environment Approval committee. thuringiensis is

4.   1 antitrypsin is (a) acidic pH of stomach

(a) An antacid (b) high temperature
(b) An enzyme (c) alkaline pH of gut
(c) Used to treat arthritis (d) mechanical action in the insect gut.
(d) Used to treat emphysema.
(e) 11. Golden rice is
(a) a variety of rice grown along the yellow river in
5. A probe which is a molecule used to locate specific China
sequences in a mixture of DNA or RNA molecules (b) long stored rice having yellow colour tint
could be (c) a transgenic rice having gene for  -carotene
(d) wild variety of rice with yellow coloured grains.
(a) A single stranded RNA
(b) A single stranded DNA 12. In RNAi, genes are silenced using
(c) Either RNA or DNA
(d) Can be ssDNA but not ssRNA. (a) ssDNA (b) dsDNA
(c) dsRNA (d) ssRNA.

6. Choose the correct option regarding retrovirus. 13. The first clinical gene therapy was done for the
(a) An RNA virus that can synthesise DNA during treatment of
infection. (a) AIDS
(b) A DNA virus that can synthesise RNA during (b) Cancer
infection. (c) Cystic fibrosis
(c) A ssDNA virus (d) SCID (Severe Combined Immuno Deficiency
(d) A dsRNA virus resulting form deficiency of ADA).

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14. ADA is an enzyme which is deficient in a genetic Reason: A gene incorporated in the bacterial
disorder SCID. What is the full form of ADA? chromosomal genome gets automatically
transferred to the crops with which the bacterium
(a) Adenosine deoxyaminase is associated.
(b) Adenosine deaminase
(c) Aspartate deaminase 20. Assertion: Cry gene expressing crop is resistant to a
(d) Arginine deaminase group of insects.
Reason: Cry proteins produced from Bacillus
thuringiensis are toxic to larvae of certain insects.
15. ‘cry genes’ that code for insecticidal toxins are
present in [2020C] 21. Assertion: To cure SCID, the first clinical gene for
ADA therapy was given.
(a) Cotton bollworms Reason: Using retroviral vector the normal gene
(b) Nematodes was delivered into the patient's cells.
(c) Corn borer
(d) Bacillus thurigiensis. 22. Assertion: A crop expressing a cry gene is usually
resistant to a group of insects.
Reason: Cry proteins produced from Bacillus
16. Which one of the following is not the product of thuringiensis are toxic to larvae of certain insects.
transgenic experiments?
23. Assertion: Hirudin is a protein that prevents blood
(a) Pest resistant crop variety clotting.
(b) High nutritional value in grains Reason: The gene encoding Hirudin is transferred
(c) Production of insulin by rDNA technique into Brassica napus, where hirudin accumulated in
(d) Drought resistant crops the seeds.

24. Assertion: The RNAi can be introduced in an

17. (a) What is biopiracy? organism by insertion of gene encoding
(b) State the initiative taken by the Indian parliament complementary RNA only.
against it. Reason: These are no methods by which in vitro
synthesised complementary RNA can be inserted
in an organism to induce RNAi (RNA interference).
 Assertion Reason:
Directions: In the following questions, a  Case Study
statement of assertion is followed by a statement
of reason Mark the correct choice as: 25. Read the text carefully and answer the questions:
(a) If both assertion and reason are true and Transgenic cows have extra gene or genes inserted
reason is the correct explanation of assertion. into their DNA. Firstly the genes for the desired
(b) If both assertion and reason are true but product is identified and sequenced. Then a gene
reason is not the correct explanation of assertion. construct containing this desired gene is
(c) If assertion is true but reason is false. introduced into female cow cells by transfection.
(d) If both assertion and reason are false. Transgenic bovine cells are selected and fused with
bovine oocytes that have had all of their
18. Assertion: To diagnose presence of a specific DNA chromosomes removed. Once fused with the
segment in a mixture, complementary pairing oocyte, the transgenic cells chromosomes are
between nucleotides is exploited. reprogrammed to direct development into an
Reason: DNA probes having radioactive isotopes embryo which can be implanted into a recipient
help to detect DNA by autoradiography. cow. The resulting transgenic cow only expresses
the transgene in her milk. This is because the
19. Assertion: Agrobacterium tumefaciens is popular in expression of the transgene is controlled by a
genetic engineering because this bacterium is promoter - specific to lactating mammary cells.
associated with the stems of all cereal and pulse The first transgenic cow was ‘Rosie’.
crops.

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(a) The gene construct with desired gene is introduced 28. What is insecticidal protein?
into female cow cells by
a) Transformation b) Transduction 29. Why does the Bt. toxin not kill the bacterium that
c) Transplantation d) Transfection produces it, but kills the insect that ingests it ?

(b) Production of transgenic cow fulfill the objective of 30. How is mammalian insulin synthesised?
a) Increased milk production
b) All of these 31. Explain how Eli Lily an American company,
c) Molecular farming produced insulin by recombinant DNA technology?
d) Increased meat production OR
How did Ely Lily synthesise the human insulin ?
(c) The name of first transgenic cow is Mention one difference between this insulin and
one produced by the human pancreas.
a) Tracy b) ANDI
c) Dolly d) Rosie 32. How ‘Rosie’ is considered different from a normal
cow? Explain.
(d) Transgenic cow is produced through the
implantation of containing transgene into recipient 33. A corn farmer has perennial problem of corn-borer
cow. infestation in his crop. Being environmentally
a) Both ova and embryo conscious he does want to spray insecticides.
b) Ova Suggest solution based on your knowledge of
c) Embryo biotechnology. Write the steps to be carried out to
d) Mammary cell achieve it.

(e) Assertion (A): Transgenes only express in the 34. How have transgenic animals proved to be
mammary glands of transgenic cow. beneficial in:
Reason (R): Transgenes are present in chromosomes of (i) Production of biological products
every cell in transgenic cow. (ii) Chemical safety testing?
a) Both A and R are true and R is the correct
explanation of A. 35. What is gene therapy? Illustrate using the example
b) Both A and R are true but R is not the correct of Adenosine Deminase (ADA) deficiency.
explanation of A. OR
c) A is true but R is false. Mention the cause and the body system
d) A is false but R is true. affected by ADA deficiency in humans. Name
the vectors used for transferring ADA-DNA into
26. Read the text carefully and answer the questions: the recipient cell in humans. Name the
Ryan is suffered from Adenosine Deaminase recipient cell.
deficiency is a hereditary disease. His parents
consulted a doctor. The doctor prescribed 36. What are Cry proteins? Name organisms that
treatment through gene therapy? produce it. How has man exploited this protein to
(a) What is gene therapy? his benefit?
(b) What is the function of adenosine Deaminase OR
enzyme? How is Bt cotton made to attain resistance
(c) In which year the first clinical gene therapy was against the bollworm.
given? OR
(d) Which tissue is obtained from the ADA patient for How is the Bt Cotton plant created as a GM
genetherapy? plant ? How it protects against the bollworm
infestation ?
 Questions OR
Why certain cotton plants are called Bt Cotton
27. Why is the genetically engineered insulin by plants ? Explain how the Bt Cotton is resistant
American company Eli Lilly preferred to the one to the pests ?
produced by conventional methods? Expalin. OR
Name the genes responsible for making Bt
Cotton plants resistant to bollworm attack.
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 How do such plants attain the resistance (c) How are the two polypeptides of a
against the bollworm attack? Explain. functional insulin chemically held together?

37. What is bio-piracy? State the initiative taken by

the Indian Parliament towards it. 46. (a) Mention the cause of ADA deficiency in
humans.
38. Name the most commonly used bioreactor in (b) How is gene therapy carried out to treat the
biotechnology labs. Mention the most essential patients suffering from this disease.?
components this bioreactor have so as to provide (c) State the possibility of a permanent cure of
the optimum conditions to the culture medium, this disease.
resulting in production of large volume of desired
product. 47. (a) Write the difference between proinsulin and
mature insulin.
39. When Bacillus thuringiensis enters a certain (b) How did American company Eli Lilly produce
insect's body, the insect gets killed, but itself human insulin using rDNA technique?
remain unaffected. Explain how it is possible?
(2020) 48. Two children, A and B aged 4 and 5 years
respectively visited a hospital with a similar
40. Cotton bollworms enjoy feeding on cotton plants genetic disorder. The girl A was provided enzyme
but get killed when feed on Bt cotton plant. Justify replacement therapy and was advised to revisit
the statement. periodically for further treatment. The girl, B was,
however, given a therapy that did not require
41. Why do lepidopterans die when they feed on Bt revisit for further treatment.
cotton plant? Explain how does it happen. (a) Name the ailments the two girls were suffering
from.
42. What is GMO? List any five possible advantages of (b) Why did the treatment provided to girl A
a GMO to a farmer. required repeated visits?
(c) How was the girl B cured permanently?
43. One of the major contribution of biotechnology is
to develop pest-resistant varieties of cotton plants. 49. Explain the various steps involved in the
Explain how it has been made possible. production of artificial insulin.

44. Describe any three potential applications of 50. Explain enzyme- replacement therapy to treat
genetically modified plants. adenosine deaminase deficiency. Mention two
disadvantages of this procedure.
45. Insulin in the human body is secreted by pancreas
as prohormone/proinsulin. The schematic 51. Recombinant DN A-technology is of great
polypetide structure of proinsulin is given below. importance in the field of medicine. With the help
This proinsulin needs to undergo processing before of a flow chart, show how this technology has
it becomes functional in the body. Answer the been used in preparing genetically engineered
questions that follow: human insulin.

52. Flow chart showing preparation of genetically

engineered human insulin is as follows:

53. What is biopiracy?

54. List any four ways by which GMOs have been

(a) State the change the proinsulin undergoes useful for enhanced crop output. [Delhi 2019]
at the time of its processing to become
functional. 55. Mention the cause of ADA deficiency
(b) Name the technique the American in humans. How has genetic engineering helped
company Eli Lilly used for the commercial patients suffering from it?
production of human insulin.

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56. Mention two objectives of setting up GEAC by our
Government.
57. (a) Name the insect that attacks cotton crops and
causes lot of damage to the crop. How has Bt
cotton plant overcome this problem and saved
the crop. Explain,
(b) Write the role of gene cryl Ab. [2020]

58. Insects in the Lepidopetran group lay eggs on

maize crops. The larvae on hatching feed on Insect gut pH was recorded as 10, 8 and 6
maize leaf and tender cob. In order to arrest the respectively for Species I, II and III respectively.
spread of three such Lepidopteran pests, Bt maize (a) Evaluate the efficacy of the Bt crop on the feeding
crops were introduced in an experimental field. habits of the three species of stem borer and
A study was carried out to see which of the three suggest which species is least susceptible to Bt
species of lepidopteran pests was most toxin.
susceptible to Bt genes and its product.
The lepidopteran pests were allowed to feed on (b) Which species is most susceptible to Bt – maize?
the same Bt-maize crops grown on 5 fields (A-E). Explain why?
The graph below shows the leaf area damaged by
these three pests after feeding on maize leaves
Using the given information, suggest why similar
for five days.
effect was not seen in the three insect species?

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 Sure Shot Questions
Chapter – 11
Organisms and Populations
MCQ 7. Which of the following forest plants controls the
light conditions at the ground?
1. Autecology is the (a) Lianas and climbers
(a) relation of a population to its environment (b) Shurbs
(b) relation of an individual to its environment (c) Tall trees
(c) relation of a community to its environment (d) Herbs
(d) relation of a biome to its environment.
8. What will happen to a well growing herbaceous
2. Biosphere is plant in the forest if it is transplanted outside the
(a) a component in the ecosystem forest in a park?
(b) composed of the plants present in the soil (a) It will grow normally,
(c) life in the outer space (b) It will grow well because it is planted in the
(d) composed of all living organisms present on same locality,
earth which interact with the physical environment. (c) It may not survive because of change in its
microclimate,
3. Ecological niche is (d) It grows very well because the plant gets more
(a) the surface area of the ocean sunlight.
(b) an ecologically adapted zone
(c) the physical position and functional role of a 9. If a population of 50 Paramecium present in a pool
species within the community increases to 150 after an hour, what would be the
(d) formed of all plants and animals living at the growth rate of population?
bottom of a lake.
(a) 50 per hour
(b) 200 per hour
4. According to Allen's Rule, the mammals from colder (c) 5 per hour
climates have (d) 100 per hour
(a) shorter ears and longer limbs
(b) longer ears and shorter limbs 10. What would be the percent growth or birth rate per
(c) longer ears and longer limbs individual per hour for the same population
(d) shorter ears and shorter limbs. mentioned in the previous question (Question 10)?
(a) 100 (b) 200
(c) 50 (d) 150
5. Salt concentration (salinity) of the sea measured in
parts per thousand is
(a) 10 – 5 (b) 30 – 70 11. A population has more young individuals compared
(c) 0 – 5 (d) 30 – 35 to the older individuals. What would be the status
of the population after some years?

6. Formation of tropical forests needs mean annual (a) It will decline.

temperature and mean annual precipitation as (b) It will stabilize.
(a) 18-25°C and 150-400 cm (c) It will increase.
(b) 5-15°C and 50-100 cm (d) It will first decline and then stabilize.
(c) 30-50°C and 100-150 cm
(d) 5-15°C and 100-200 cm. 12. What parameters are used for tiger census in our
country’s national parks and sanctuaries?

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(a) Pug marks only (b) dN/dt = rN
(b) Pug marks and faecal pellets (c) dN/dt = r N(K-N/K)
(c) Faecal pellets only (d) dN/dt = rN(K-rN/K)
(d) Actual head counts

13. Which of the following would necessarily decrease 19. Sea anemone gets attached to the surface of the
the density of a population in a given habitat? hermit crab. The kind of population interaction
exhibited in this case is
(a) Natality > mortality (a) amensalism
(b) Immigration > emigration (b) commensalism
(c) Mortality and emigration (c) mutualism
(d) Natality and immigration (d) parasitism.

14. A protozoan reproduces by binary fission. What will

be the number of protozoans in its population after 20. Important attributes belonging to population but
six generations? not to an individual are
(a) 128 (b) 24 (i) Birth rate and death rate
(c) 64 (d) 32 (ii) Male and female
(iii) Birth and death
Soln. (c): (iv)Sex – ratio.
Select the correct option from the given options.
(a) (i) only (b) (ii) only
By binary fission, an individual protozoan will divide
(c) (ii) and (iii) (d) (i) and (iv)
in two. In this way after six generations their
number will be 64.
Assertion Reasoning
15. In 2005, for each of the 14 million people present in
a country, 0.028 were born and 0.008 died during 21. Given is the age pyramid of population in one of
the year. Using exponential equation, the number the states in India as per 2011 census. It depicts
of people present in 2015 is predicted as the male population on the left hand side, female
(a) 25 millions (b) 17 millions population on the right hand side, newborns
(c) 20 millions (d) 18 millions. towards the base and gradually increasing age
groups as we move from base to the top, with the
16. Lichens are the associations of oldest population at the top. Study this pyramid
and comment upon the appropriateness of the
(a) Bacteria and fungus Assertion and the Reason. [2022 – 23]
(b) Algae and bacterium
(c) Fungus and algae
(d) Fungus and virus.

17. Which one of the following organisms reproduces

sexually only once in its life time?
(a) Banana plant (b) Mango
(c) Tomato (d) Eucalyptus Assertion (A): It is a stable population.
Reason (R): The pre-reproductive and reproductive
individuals are almost in equal numbers and the
18. Swathi was growing a bacterial colony in a culture post reproductive individuals are relatively fewer,
flask under ideal laboratory conditions where the (a) Both (A) and (R) are true and (R) is the correct
resources are replenished. Which of the following explanation of (A),
equations will represent the growth in this case? (b) Both (A) and (R) are true and (R) is not the
(Where population size is N, birth rate is b, death correct explanation of (A),
rate is d, unit time period is t, and carrying capacity (c) (A) is true but (R) is false,
is K). (d) (A) is false but (R) is true.
(a) dN/dt=KN

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22. Assertion (A): The Monarch butterfly is highly start spreading fast because the invaded land does
distasteful to the predators. not have the natural predators.
Reason (R): The butterfly has a very rough skin
which is not palatable, Case Study
(a) Both (A) and (R) are true and (R) is the correct
explanation of (A), 28. Read the following passage and answer any four
(b) Both (A) and (R) are true and (R) is not the questions from (i) to (v):
correct explanation of (A), Acacia plants are particularly common in drier
(c) (A) is true, but (R) is false, tropical and subtropical environments in the world.
(d) (A) is false, but (R) is true. The swollen thorn acacias, which form obligate
mutualisms with Pseudomyrmex, a species of ants,
are restricted to the New World. Swollen thorn
Directions: In the following questions, a statement acacias show several characteristics related to their
of assertion is followed by a statement of reason obligate association with ants, including enlarged
Mark the correct choice as: thorns with a soft, easily excavated pith; year-round
(a) If both assertion and reason are true and reason leaf production; enlarged foliar nectaries; and
is the correct explanation of assertion. leaflet tips modified into concentrated food sources
(b) If both assertion and reason are true but reason called Beltian bodies. The thorns provide living
is not the correct explanation of assertion. space, while the foliar nectaries provide a source of
(c) If assertion is true but reason is false. sugar and liquid. Beltian bodies are a source of oils
(d) If both assertion and reason are false. and protein. Resident ants vigorously guard these
resources against encroachment by nearly all
23. Assertion: Prolonged intraspecific competition comers, including other plants.
causes an increase in the size of the niche of a
population. (i) The association between the genus of Acacia
Reason: In such a population, use of a new type of and Pseudomyrmex species of ants depict
resource will increase through the generations. population interactions, known as:

24. Assertion: The community of an ecotone commonly (a) Competition (b) Amensalism
contains the organisms of each of the overlapping (c) Mutualism (d) Predation
communities and in addition the organisms which
are restricted to the ecotone. (ii) In exchange for food and shelter, ants protect
Reason: The tendency for increased variety and Acacias from the attacks of
density at community junctions is known as the
edge effect. (a) fungi (b) bacteria
(c) herbivore (d) carnivores
25. Assertion: Daphnia populations in a water body, at
different seasons of a year showed marked (iii) The above interaction suggest that the
variations in their body morphology. relationship between the two species is an example
Reason: Cyclomorphosis in some organisms is of:
influenced by the variations in temperatures (a) Competitive release
prevailing in their water bodies at different seasons. (b) Competitive exclusion
(c) Co – evolution
26. Assertion: Species are groups of potentially (d) Resource partitioning
interbreeding natural populations which are
isolated from other such groups. (iv) The removal of resident ants from the Acacias
Reason: Distinctive morphological characters are will lead to:
displayed due to reproductive isolation. I. Reduced growth of Acacias
II. Increased growth of Acacias
27. Assertion: The prickly pear cactus introduced into III. Reduced population of ant species
Australia in early 1920s caused havoc by spreading IV. Increased population of ant species
rapidly into millions of hectares of land range. Choose the correct alternative from the above
Reason: When certain exotic species are introduced statements:
into a geographical area, they become invasive and (a) Only I is true (b) I and III are true

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 (c) III and IV are true (d) I and IV are true 31. If a marine fish is placed in the fresh water
(v) Given below is a graphical representation of aquarium, will the fish be able to survive? Why or
ants and the Acacia shoots with abundance of why not?
herbivorous insects:
32. Explain the birth rate and death rate in the
population with the help of an example. What is
age pyramid?
OR
What is age pyramid?

33. Name important defence mechanisms in the plant

The conclusion drawn from the above data is: against herbivory.
(a) Acacia shoots will have higher rates of growth
with resident ant species. 34. ome organisms suspend their metabolic activities
(b) Acacia shoots will have neutral effect on to survive in unfavourable conditions. Explain with
growth with without resident ants species. the help of any four examples.
(c) Acacia shoots will have higher rates of growth
without resident ant species. 35. How does Monarch butterfly defend itself from the
(d) Growth of Acacia shoots is independent of predators? Explain.
resident ant species.
36. Explain brood parasitism with the help of an
29. Read the text carefully and answer the questions: example.
During teaching about various environmental
factors, a teacher draws a figure that depicts 37. Why the plants that inhabit a desert are not found
history strategies for three plant species (X, Y and in a mangrove? Give reasons.
Z) along 3 axes - the strength of competition with
other organisms, level of disturbance in the habitat 38. How do the following organisms pull through the
and level of environmental stress in the habitat. adverse environmental conditions?
Species X grows in habitats where competition (a) Fungi
among species is high but disturbance and stress (b) Zooplankton
are low. Species Y grows in habitats with high (c) Bear
environmental stress but with low intraspecies (d) Snails
competition. Species Z grows in highly disturbed
habitats with low environmental stress. 39. Explain with the help of figure, the three different
types of age pyramids represented by a human
population.

40. Mention the special adaptation evolved in

parasites and why?

41. How do kangaroo, rats and desert plants adapt

(a) Discribes the features regarding plant type X? themselves to survive in their extreme habitat?
Explain.
(b) What is the reason for environmental stress?
(c) Y type of plants grow under which condition and
42. An orchid plant is growing on the branch of mango
what kind of seed it’s produces?
(d) Plant growth rate is low in area of high stress tree. How do you describe this interaction
and high disturbance. Justify. between the orchid and a mango tree ?

43. (i) What is “population” according to you as

biology student ?
 Questions (ii) “The size of a population for any species is not a
30. Explain in short the adaptive mechanism of static parameter. “Justify the statement with
suspension. Justify your answer using an example. specific reference to fluctuation in the population
density of a region in a given period of time.

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44. (i) Name the two growth models that represent Study the schematic representation given above
population growth and draw the respective growth and answer the following questions.
curves they represent. (a) Identify A in it.
(ii) State the basis for the difference in the shape of (b) Identify B in it.
these curves. (c) When population density at time t is N as shown
(iii) Which one of the curves represent the human above, write the population density at time t +1 in
population growth at present ? Do you think such a the form of an equation using appropriate symbols.
curve is sustainable? Give reason in support of your
answer. 53. Study the age pyramids A', 'B' and 'C of the human
population given below and answer the questions
45. What would be the best method to measure the that follow:
total population density of the number of fishes in
river and why?

46. (a) How will you measure population density of

fish in a lake ?
(b) In a pond, there are 100 frogs. 20 more were (a) Identify pyramids 'B' and 'C’.
born in a year. Calculate the birth rate of this (b) Write the basis on which the above pyramids
population. are plotted.
47. Differentiate between parasitism and competition,
giving one example of each. State the common 54. Study the graph given below and answer the
characteristic they share. questions that folk)w.

48. Name the interaction that exists between Cuscuta

and shoe – flower plant.

49. Name the type of interaction seen between fig

and wasps.
(a) Write the status of food and space in the curves
50. Write a short note on: A and B.
(i) Adaptations of desert plants and animals. (b) In the absence of predators, which one of the
(ii) Adaptations of plants to the water scarcity. two curves would appropriately depict the prey
(iii) Behavioural adaptations in animals. population?
(iv) Importance of light to plants. (c) Time has been shown on X-axis and there is a
(v) Effect of temperature or water scarcity and the parallel dotted line above it. Give the significance of
adaptations of animals. this dotted line.

51. The population of a metro city experiences 55. Draw and explain expanding age pyramids of
fluctuations in its population density over a period human population. Why is it so called?
of time.
(a) When does the population in a metro city tend 56. (a) Write the importance of measuring the size of
to increase? a population in a habitat or an ecosystem,
(b) When does the population in a metro city tend (b) Explain with the help of an example how the
to decline? percentage cover is a more meaningful measure of
(c) If N is the population density at time 't', write population size than more numbers.
the population density at time 't + 1'.
57.
52.

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 A forest hardly has any carnivores. Census of (b) Parasites are host specific and tend to coevolve.
herbivorous mammals was taken and plotted as a How would the parasite respond if the host evolve a
graph shown above. Identify the curve that will certain mechanism to resist or reject the parasite?
explain the population growth of herbivores. Give
reason to your answer. 59. Mention the special adaptations evolved in
parasites and why?
58. (a) Write how parasites have evolved with 60. Describe the mutual relationship between fig tree
adaptation to co-exist with their host in an and wasp and comment on the phenomenon that
ecosystem. operates in their relationship.

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 Sure Shot Questions
Chapter – 12
Ecosystem
6. Which of the following ecosystems is most
 MCQ productive in terms of net primary production?
(a) Deserts (b) Tropical rainforests
1. Decomposers like fungi and bacteria are (c) Oceans (d) Esturies

(i) Autotrophs
(ii) Heterotrophs 7. Pyramid of numbers is
(iii) Saprotrophs (a) Always upright
(iv) Chemo – autotrophs. (b) Always inverted
(c) Either upright or inverted
Choose the correct answer. (d) Neither upright nor inverted.
(a) (i) and (iii) (b) (i) and (iv)
(c) (ii) and (iii) (d) (i) and (ii) 8. Approximately how much of the solar energy that
falls on the leaves of a plant is converted to
chemical energy by photosynthesis?
2. The process of mineralisation by microorganisms
helps in the release of (a) Less than 1% (b) 2-10%
(c) 30% (d) 50%
(a) inorganic nutrients from humus
(b) both organic and inorganic nutrients from detritus 9. Among the following, where do you think the
(c) organic nutrients from humus process of decomposition would be the fastest?
(d) inorganic nutrients from detritus and formation of
humus. (a) Tropical rainforest
(b) Antarctic
(c) Dry arid region
3. Productivity is the rate of production of biomass (d) Alpine region
expressed in terms of
3
(i) (kcalm ) yr 1 10. Given below is a diagram of an ecological pyramid
of numbers. Choose the correct food chain from
(ii) g 2 yr 1 the list of food chain given, that represent the
(iii) g 1 yr 1 given pyramid.
[2023]
(iv) (kcalm2 ) yr 1

(a) (ii) (b) (iii)

(c) (ii) and (iv) (d) (i) and (iii)
(a) Grass  Goat  Fox  Tiger
4. An inverted pyramid of biomass can be found in (b) Mice  Cat  Hyena  Cheetah
which ecosystem? (c) Grass  Rabbit  Fox  Flea
(a) Forest (b) Marine (d) Grass  Insects  Sparrow  Snake
(c) Grassland (d) Tundra
11. During the process of ecological succession,
5. Which of the following is not a producer? the changes that take p ace in communities are
(a) Spirogyra (b) Agaricus (a) orderly and sequential
(c) Volvox (d) Nostoc (b) random

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(c) very quick (b) Prevention of soil erosion
(d) not influenced by the physical environment. (c) Pollutant absorption and reduction of the threat of
global warming
12. Among the following biogeochemical cycles, (d) All of the above
which one does not have losses due to respiration?
(a) Phosphorus (b) Nitrogen 20. The primary productive in an ecosystem is
(c) Sulphur (d) All of the above expressed as [2023]
(a) gm2 yr 1 (b) gm2 yr
13. The sequence of communities of primary
succession in water is (c) K cal m2 yr 1 (d) K cal m2
(a) phytoplankton, sedges, free-floating
hydrophytes, rooted hydrophytes, grasses and 21. Which of the following food chains is the major
trees conduit for energy flow in terrestrial and aquatic
(b) phytoplankton, free-floating hydrophytes, ecosystems respectively? [2022 – 23]
rooted hydrophytes, sedges, grasses and trees Terrestrial Aquatic
(c) free-floating hydrophytes, sedges, ecosystem ecosystem
phytoplankton, rooted hydrophytes, grasses and (a) Grazing Grazing
trees (b) Detritus Detritus
(d) phytoplankton, rooted submerged (c) Detritus Grazing
hydrophytes, floating hydrophytes, reed swamp,
(d) Grazing Detritus
sedges, meadow
22. In the illustration given below of a simplified
14. The reservoir for the gaseous type of
food web on an island, the arrows indicate the
biogeochemical cycle exists in
direction of energy flow and the Roman
(a) stratosphere (b) atmosphere
numbers indicate species within the food web.
(c) ionosphere (d) lithosphere.

15. If the carbon atoms fixed by producers already

have passed through three species, the trophic level
of the last species would be
(a) Scavenger
(b) Tertiary producer
(c) Tertiary consumer
(d) Secondary consumer.
At which trophic level or levels does the species VIII
16. Which of the following types of ecosystem is function?
expected in an area where evaporation exceeds (a) 2nd and 3rd consumer
precipitation, and mean annual rainfall is below 100 (b) 1st consumer
mm? (c) Producer
(a) Grassland (b) Shurbby forest (d) 3rd and 4th consumer
(c) Desert (d) Mangrove
 Assertion Reason
17. The zone at the edge of a lake or ocean which
is alternatively exposed to air and immersed in 23. Assertion (A): Decomposition process is slower if
water is called detritus is rich in lignin and cutin.
(a) pelagic zone (b) benthic zone Reason (R): Decomposition is largely an oxygen-
(c) lentic zone (d) littoral zone. requiring process,
(a) Both (A) and (R) are true and (R) is the correct
18. Edaphic factor refers to explanation of (A),
(a) water (b) soil (b) Both (A) and (R) true, but (R) is not the correct
(c) relative humidity (d) altitude. explanation of (A),
(c) (A) is true, but (R) is false,
19. Which of the following is an ecosystem service (d) (A) is false, but (R) is true.
provided by a natural ecosystem?
(a) Cycling of nutrients
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24. Assertion (A): Land occupying 30 percent of a) Both A and R are true and R is the correct
the earth’s surface and its productivity is more than explanation of A.
three times as compared to oceans. b) Both A and R are true but R is not the correct
Reason (R): Oceans, despite occupying about 70 explanation of A.
percent of the surface but their productivity are c) A is true but R is false.
only 55 billion tons. d) A is false but R is true.
a) Both A and R are true and R is the correct
explanation of A. 29. Assertion (A): The Global ecosystem is divided
b) Both A and R are true but R is not the correct into two basic categories: terrestrial and aquatic.
explanation of A. Reason (R): Both terrestrial and aquatic ecosystems
c) A is true but R is false. are different from each other in their basic aspects.
d) A is false but R is true. a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the correct
25. Assertion (A): An ecosystem can be visualized as explanation of A.
a functional unit of nature. c) A is true but R is false.
Reason (R): Living organisms interact among d) A is false but R is true.
themselves and also with the surrounding physical
environment in the ecosystem.  Case Study
a) Both A and R are true and R is the correct
explanation of A.
30. Two blood samples of suspects ‘A’ and ‘B’ were sent
b) Both A and R are true but R is not the correct
to the Forensic Department along with sample ‘C’
explanation of A.
from the crime scene. The Forensic Department
c) A is true but R is false.
was assigned the responsibility of running the
d) A is false but R is true.
samples and matching the samples of the suspects
with that of the sample from the scene of the crime
and thereby identifying the culprit.
26. Assertion (A): An ecosystem is an interaction
between biotic and abiotic components.
Reason (R): A.G. Tansley coined the term
ecosystem.
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the correct
explanation of A.
c) A is true but R is false.
d) A is false but R is true.

27. Assertion (A): At present we have a large number

of communities in the world.
Reason (R): They are formed as such we have now.
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the correct (a): In genetic fingerprinting, the ‘probe’ refers to –
explanation of A.
c) A is true but R is false. 1. A radioactively labelled double stranded RNA
d) A is false but R is true. molecule.
2. A radioactively labelled double stranded DNA
molecule.
28. Assertion (A): An aquatic ecosystem is fairly a 3. A radioactively labelled single stranded DNA
self - sustainable unit. molecule.
Reason (R): An aquatic ecosystem exhibits 4. A radioactively labelled single stranded RNA
productivity, decomposition, and energy flow molecule.
only.

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(b): What does ‘minisatellite’ and ‘microsatellite’ 3. Growth hormone
mean in relation to DNA Fingerprinting? 4. None of the above

(c): How does polymorphism arise in a population? (d): Construction of recombinant DNA involves:

(d): State the steps involved in DNA Fingerprinting in a 1. cleaving and joining of DNA segments with
sequential manner. endonuclease
2. cleaving DNA segments with endonuclease and re-
31. When you insert a piece of alien DNA into a cloning joining with ligase
vector and transfer it into a bacterial, plant, or 3. cleaving and re-joining DNA segments with ligase
animal cell, the alien DNA gets multiplied. In 4. cleaving DNA segments with ligase and re-joining
almost all recombinant technologies, the ultimate with endonuclease
aim is to produce a desirable protein. Hence, there
is a need for the recombinant DNA to be (e): Any DNA molecule that has the ability to replicate
expressed. The foreign gene gets expressed under in an appropriate host cell, to which the desired
appropriate conditions. The expression of foreign gene are integrated for cloning:
genes in host cells involves understanding many
technical details. After having cloned the gene of 1. Plasmid
interest and having optimised the conditions to 2. Linker
induce the expression of the target protein, one 3. Vector
has to consider producing it on a large scale. Can 4. adapter
you think of any reason why there is a need for
large-scale production? If any protein encoding
gene is expressed in a heterologous host, it is  Questions
called a recombinant protein. The cells harbouring
cloned genes of interest may be grown on a small
32. (a) Taking an example of a small pond, explain how
scale in the laboratory. The cultures may be used
for extracting the desired protein and then the four components of an ecosystem function as a
purifying it by using different separation unit.
techniques. (b) Name the type of food chain that exists in a pond.

33. Write the equation that helps in deriving the net

(a): Which of the following should be chosen for the
primary productivity of an ecosystem.
best yield if one were to produce a recombinant
protein in large amounts?
34. Write the relationship between productivity, gross
1. A continuous culture system
primary productivity, net primary productivity and
2. A stirred-tank bioreactor without in-lets and out-
secondary productivity.
lets
3. Laboratory flask of the largest capacity
35. How would you differentiate between gross
4. None of the above
primary productivity from net primary productivity
and secondary productivity of an ecosystem.
(b): The process of separation and purification of
expressed protein before marketing is called
36. (a) What is primary productivity? Why does it vary
in different types of ecosystems?
1. upstream processing
(b) State the relation between gross and net primary
2. downstream processing productivity.
3. bioprocessing
4. postproduction processing
37. How is humus formed? Mention any three
characteristics of humus.
(c): Genetically engineered bacteria are used for the
production of:
38. Why is earthworm considered a farmer's friend?
1. Thyroxine Explain humification and mineralisation occurring
2. Human insulin in a decomposition cycle.

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 energy that is available to the first and third trophic
39. How does a detritivore differ from a decomposer? levels.
Explain with an example each.
51. "In a food chain, a trophic level represents a
40. How is detritus decomposed step-by-step by functional level, not a species". Explain.
different agents and made available as nutrients to
the plants? Explain. 52. (a) The pyramid of energy is always upright'.
Explain.
41. "Man can be a primary as well as a secondary (b) Explain with the help of labelled diagrams, the
consumer." Justify this statement. difference between an upright pyramid of biomass
and an inverted pyramid of biomass.
42. What is a detritus food chain made up of? How do
they meet their energy and nutritional 53. (a) What is a trophic level in an ecosystem? What
requirements? is 'standing crop' with reference to it?
(b) Explain the role of the 'first trophic level' in an
43. State what does standing crop of a trophic level ecosystem.
represent. (c) How is the detritus food chain connected with the
grazing food chain in a natural ecosystem?
44. Justify the importance of decomposers in an
ecosystem. 54. "It is often said that the pyramid of energy is
always upright. On the other hand, the pyramid of
45. "It is possible that a species may occupy more than biomass can be both upright and inverted." Explain
one trophic level in an ecosystem at the same with the help of examples and sketches.
time". Explain with the help of one example.
55. (a) With suitable examples, explain the energy flow
46. Construct labelled grazing and detritus food chain through different trophic levels. What does each
with minimum 3 trophic levels each. bar in this pyramid represent?
(b) Write any two limitations of ecological pyramids.
47. (a)How many primary producers do you think will
be needed to support six tertiary consumers In a 56. How is ‘stratification’ represented in a forest
grassland ecosystem? ecosystem?
(b) Draw a grassland pyramid to substantiate your
answer. 57. What does ‘R’ represent in the given equation for
productivity in an ecosystem?
48. Why the pyramid of energy is always upright? GPP – R = NPP.
Explain.
58. “Man can be primary as well as secondary
49. Construct a pyramid of numbers considering a big consumer”. Justify this statement.
banyan tree supporting a population of insects,
small birds and their predators. 59. (a) What is a trophic level in an ecosystem? What
is ‘standing crop’ with reference to it?
50. (a) Name an ideal pyramid existing in an (b) Explain the role of the 'first trophic level’ in an
ecosystem. Construct it upto its three trophic ecosystem,
levels along with their names. (c) How is the detritus food chain connected with the
(b) The sun provides 1,000,000 J of sunlight (solar grazing food chain in a natural ecosystem?
energy) to an ecosystem. Write the amount of

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 Sure Shot Questions
Chapter – 13
Biodiversity and Conservation
 MCQ (b) i  D, ii  C, iii  A,iv B
(c) i  C, ii  A, iii  B,iv D
1. Which of the following countries has the highest (d) i  C, ii  A, iii  D,iv B
biodiversity?
(a) Brazil (b) South Africa
(c) Russia (d) India
7. What is common to the following plants:
Nepenthes, Psilotum, Rauwolfia and Aconitum?
2. Which of the following is not a cause for loss of (a) All are ornamental plants.
biodiversity?
(b) All are phylogenic link species.
(a) Destruction of habitat
(c) All are prone to over exploitation.
(b) Invasion by alien species
(d) All are exclusively present in the Eastern
(c) Keeping animals in zoological parks
Himalayas.
(d) Over-exploitation of natural resources

3. Which of the following is not an invasive alien

species in the Indian context? 8. The one-horned rhinoceros is specific to which of
(a) Lantana (b) Cynodon the following sanctuary?
(c) Parthenium (d) Eichhornia (a) Bhitar Kanika (b) Bandipur
(c) Kaziranga (d) Corbett park.
4. Where among the following will you find pitcher
plant?
(a) Rainforest of North – East India 9. Amongst the animal groups given below, which
(b) Sunderbans one has the highest percentage of endangered
(c) Thar Desert species?
(d) Western Ghats (a) Insects (b) Mammals
(c) Amphibian (d) Reptiles

5. Which one of the following is not a feature of

biodiversity hotspots? 10. Which one of the following is an endangered plant
(a) Large number of species species of India?
(b) Abundance of endemic species (a) Rauwolfia serpentina
(c) Mostly located in the po ar regions (b) Santalum album (Sandalwood)
(d) Mostly located in the tropics (c) Cycas beddonei
(d) All of the above
6. Match the animals given in column A with their
location in column B.

Column A Column B 11. What is common to Lantana, Eichhomia and

(i) Dodo A. Africa African catfish?
(ii) Quagga B. Russia (a) All are endangered species of India,
(iii) Thylacine C. Mauritius (b) All are keystone species,
(iv) Stellar’s sea cow D. Australia (c) All are mammals found in India,
Choose the correct match from the following. (d) All the species are neither threatened nor
indigenous species of India.
(a) i  A, ii  C, iii  B,iv D

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12. The extinction of passenger pigeon was due to 19. Which of the below mentioned regions exhibit less
(a) increased number of predatory birds seasonal variations?
(b) over exploitation by humans (a) Tropics (b) Temperates
(c) non-availability of the food (c) Alpines (d) Both (a) and (b)
(d) bird flu virus infection.
Soln. (a) : There are no unfavourable seasons in
tropics. Continued favourable environment has helped
tropical organisms to gain more niche specialisation
13. Which of the following statements is correct? and increased diversity. Hence, tropics exhibit lesser
(a) Parthenium is an endemic species of our seasonal variations.
country,
(b) African catfish is not a threat to indigenous 20. The historic convention on Biological Diversity held
catfishes. in Rio de Janeiro in 1992 is known as
(c) Steller's sea cow is an extinct animal, (a) CITES Convention
(d) Lantana Is popularly known as carrot grass. (b) The Earth Summit
(c) G – 16 Summit
(d) MAB Programme.
14. Among the ecosystem mentioned below, where Soln. (b) : Earth Summit at Rio de Janeiro (1992), Brazil,
can one find maximum biodiversity? promoted Convention on Biological Diversity (CBD)
(a) Mangroves (b) Desert which was signed by 152 nations. Its recommendations
(c) Coral reefs (d) Alpine meadows came into effect on 29th Dec. 1993. India became a
party to this Convention on Biological Diversity in May,
1994.
15. Species – area relationship is represented on a log
21. What is common to the techniques (i) in
scale as [2020]
v/frofertilisation, (ii) Cryopreservation and (iii)
(a) Hyperbola
tissue culture?
(b) Rectangular hyperbola
(a) All are in situ conservation methods,
(c) Linear inverted.
(b) All are ex situ conservation methods,
(c) All require ultra modern equipment and large
16. Which of the following forests is known as the space,
'lungs of the planet earth'? (d) All are methods of conservation of extinct
(a) Taiga forest (b) Tundra forest organisms.
(c) Amazon rainforest
Soln. (b): Ex situ method is conservation of those
(d) Rainforests of North East India
organisms, whose species may become extinct or
decline heavily in number (due to variety of reasons) in
their natural habitat. This includes seed banks,
17. The active chemical drug reserpine is obtained cryopreservation, tissue culture, in vitro fertilisation,
from etc.
(a) Datura (b) Rauwolfia
(c) Atropa (d) Papaver.  Assertion Reason:
Soln. (b) : Reserpine is an indole alkaloid molecule that
22. Assertion: A community with more species is more
has been used as an antihypertensive drug, i.e., drug to
stable than that with less species.
lower blood pressure. It can be isolated from the dried
Reason: More the number of species, lesser the
roots of Rauwoifia serpentina (Sarpagandha).
variation in the total biomass production year after
18. Which of the following group exhibit more species year,
diversity? (a) Both assertion and reason are true, and reason
(a) Gymnosperms (b) Algae is the correct explanation of assertion,
(c) Bryophytes (d) Fungi (b) Both assertion and reason are true, but reason
is not the correct explanation of assertion,
Soln. (d) (c) Assertion is true but reason is false, (d) Both
assertion and reason are false. [2020 – 21]

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 Directions: In the following questions, a statement of  Case Study
assertion is followed by a statement of reason Mark
the correct choice as:
29. Read the text carefully and answer the questions:
(a) If both assertion and reason are true and reason is
For many decades, ecologists believed that
the correct explanation of assertion.
communities with more species, generally, tend to be
(b) If both assertion and reason are true but reason is
more stable than those with
not the correct explanation of assertion.
less species are less stable. On a log scale, the
(c) If assertion is true but reason is false.
relationship becomes linear. A stable community
(d) If both assertion and reason are false.
should not show too much variation in productivity
from year to year; it must be either resistant or
23. Assertion: A sanctuary is formed for the
resilient to occasional disturbances (natural or man -
conservation of animals only.
made), and it must also be resistant to invasions by
Reason: Restricted human activities are allowed in
alien species. It is necessary to conserve biodiversity.
sanctuaries.
They can be grouped into three categories: narrowly
utilitarian,
broadly utilitarian, and ethical. The broadly utilitarian
24. Assertion: In case, a species becomes extinct, the argument says that biodiversity plays a major role in
plant and animal species associated within an many ecosystem services that nature provides.
obligatory way also become extinct.
Reason: When a host fish species becomes extinct, (a) Therivet popper hypothesis used by
its unique assemblage of parasites also become a) Edward Wilson
extinct. b) Paul Ehrlich
c) Odrum
d) Tilman

25. Assertion: Tropical latitudes have greater biological (b) Increased diversity contributed to higher
diversity than temperate latitudes. productivity.
Reason: Tropical regions remain relatively a) Tilman
undisturbed for millions of years. b) Paul Ehrlich
c) Edward Wilson
d) Odrum
26. Assertion: The species diversity present in a given
(c) The organisation responsible for maintaining Red
community or habitat is referred to as alpha
Data Book is
diversity.
a) IBWL b) IUCN
Reason: Alpha diversity is usually expressed by
c) WWF d) CITES
species richness and species evenness in that
community habitat.
(d) Amazon rainforests are considered as ‘lungs of the
planet’ as they contribute of the total oxygen in the
earth’s atmosphere.
27. Assertion: Decrease in species diversity occurs as a) 15% b) 20%
we ascend a high mountain. c) 30% d) 10%
Reason: Decrease in species diversity occurs with
increase in altitude due to rise in temperature. (e) Assertion (A): The ethical argument for conserving
biodiversity relates to what we owe to millions of
plant, animal and microbe species with whom we
28. Assertion: The presently occurring species share this planet.
Reason (R):we need to realise that every species do
extinction is different from the earlier mass
extinction. not have intrinsic value
Reason: Present species extinction is due to natural a) Both A and R are true and R is the correct
explanation of A.
causes, whereas the earlier extinction was due to
manmade causes. b) Both A and R are true but R is not the correct
explanation of A.
c) A is true but R is false.

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 d) A is false but R is true. a) (a) - insects, (b) - mollusces
30. Read the text carefully and answer the questions: b) (a) - mollusces, (b) - crustaceans
In our biosphere immense diversity exists not only c) (a) - crustaceans, (b) - insect
at the species level but at all levels of biological d) (a) - other group animal, (b) - insect
organisation ranging from macromolecules within
cells to biomes. The most important of them are
genetic diversity a single species might show high  Questions
diversity at the genetic level over its distributional
range. Species diversity, Ecological diversity. 31. Explain the hypothesis postulated by Stanford
According to IUCN (2004), the total number of ecologist Paul Ehrlich.
plant and animal species described so far is slightly
more than 1.5 million. More than 70 percent of all 32. How is biodiversity important for functioning of an
the species recorded are animals, Although India ecosystem?
has only 2.4 percent of the world’s land area, its
share of the global species diversity is an 33. Since the origin of life on the earth, there
impressive 8.1 percent. were five episodes of mass extinction of
species. How is ‘sixth extinction’ presently in
(a) The Western Ghats have a greater diversity than progress, different from previous episodes?
the Eastern Ghats. Who is responsible for ‘Sixth Extinction’? List
a) Birds species any four points that can help to overcome this
b) All of these disaster.
c) Amphibian species
d) Reptile species 34. Give three hypotheses for explaining why
tropics show greatest levels of species
(b) India has more than: richness.
a) 50,000 genetically different strains of rice
b) None of these 35. What are sacred groves? What is their role in
c) Both 50,000 genetically different strains of rice conservation?
and 1,000 varieties of mango OR
d) 1,000 varieties of mango The sacred groves of Aravalli hills and Ooty
botanical garden both aim at biodiversity
(c) The term biodiversity is popularised by conservation. How do they differ in their
a) Edward Wilson approach?
b) Paul Ehrlich
c) Tilman 36. Suggest two practices giving one example of
d) Odum each, that help protect rare or threatened
species.
(d) A single species might show high diversity at the
genetic level over its distributional range. What kind of 37. Analyse the effect of ‘Alien species invasion’
diversity does it represent? on the biodiversity of a given area. Provide two
a) Species diversity examples.
b) Ecological diversity 38. List six advantages of “ex-situ’” approach to
c) None of these conservation of bidoversity.
d) Genetic diversity
39. Explain any two most important levels of
(e) Identify (a) and (b) in the figure given below biological organisation showing biodiversity
showing major taxa of invertebrates. with the help of an example each.

40. Quote six basic reasons why should we value

the biodiversity existing on earth?
OR
Biodiversity must be conserved as it plays an
important role in many ecosystem services
that nature provides. Explain any two services
of ecosystem.
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 41. With the suitable graph, explain the species 52. ′𝐼𝑛 − 𝑠𝑖𝑡𝑢′ conservation can help
area relationship given by Alexander von endangered/ threatened species. Justify the
Humboldt. statement.
(i) Why should we conserve biodiversity ? How
can we do it ? 53. Many plant and animal species are on the
(ii) Explain the importance of biodiversity hot- verge of their extinction because of loss of
spots and sacred groves. forest land by indiscriminate use by the
humans. As a biology student what method
42. How did Dr. David Tilman relate would you suggest along with its advantages
experimentally, the stability of a community that can protect such threatened species from
and its species richness? Explain. getting extinct?

43. What are the consequences of loss of 54. Compare narrowly utilitarian and broadly
biodiversity in a region? Explain. utilitarian approaches to conserve biodiversity,
with the help of suitable examples.
44. List four causes of biodiversity loss.
55. There is a great concern all over the world to
45. Alien species invasion has been a threat to conserve biodiversity for maintaining
biodiversity. Justify with the help of a suitable ecological balance in nature. Explain giving
example. List any other three causes three reasons. Write different ways that have
responsible for such a loss. helped in increasing tiger population in our
country.
46. Name and describe any three causes of
biodiversity losses. 56. Many plant and animal species are on the
verge of their extinction because of loss of
47. Since the origin of life on Earth, there were forest land by indiscriminate use by the
five episodes of mass extinction of species. humans. As a biology student what method
(a) How is the 'Sixth Extinction', presently in would you suggest along with its advantages
progress, different from the previous that can protect such threatened species from
episodes? getting extinct?
(b) Who is mainly responsible for the 'Sixth [Delhi 2015]
Extinction'? 57. Tigers inhabit forests. Over the past many
(c) List any four points that can help to decades the tiger population was on the
overcome this disaster. decline in our country. A project ‘Save Tiger’
was launched in 1973 to conserve this precious
48. Explain giving three reasons, why tropics show species. It is heartening to see in the last
greatest levels of species diversity? couple of decades that there has been a
gradual increase in the tiger population in our
49. (a) Enlist two criteria that are used to identify country.
a region for maximum protection as Answer the questions:
'Biodiversity hotspot'. (a) Mention one major cause responsible for
(b) Name any two "hotspot" regions in our the decline in tiger population,
country. (b) Write one main effort of the biodiversity
conservationists that must have helped in the
50. (a) Explain the concept of endemism. increase in tiger population.
(b) Name four regions in and around our (c) State how it is possible to count the number
country that are considered hotspots. of tigers in a forest area.

51. Explain any three ways other than zoological

parks, botanical gardens and wildlife 58. Identify ‘a’ and ‘b’ in the figure given below
sanctuaries by which threatened species of representing proportionate number of major
plants and animals are being conserved 'ex- vertebrate taxa. [Delhi 2014]
situ'.

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 (i) Which of the two graphs depicts tropical
region and temperate regions respectively?
(ii) Which of the two region (X) or (Y) will show
high biological diversity and why?

60. “Biodiversity plays a major role in many

ecosystem services that nature provides.”

(a) Describe any two broadly utilitarian

59. The graphs (X) and (Y) below depict the diurnal arguments to justify the given statement,
variations in the solar radiations in the month (b) State one ethical reason of conserving
of June (Summer) and in December (Winters): biodiversity.

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