Page 144 How do organisms Reproduce Chap 8

CHAPTER 8
How do organisms Reproduce

1. PRODUCTION 4. Fragmentation
Reproduction is the process by which organisms The body of a multicellular organism breaks into two
produce young ones of their own kind. Organisms or more fragments and each one grows into a new
reproduce for the continuation and perpetuation of individual (Spirogyra).
race.
5. Regeneration
1. Reproduction is essential because it brings
continuation of life, preservation of species, The process of getting back a full organism from the
replacement of dead individuals in the population. cut parts of an organism (Hydra and Planarian).
It also introduces variations in the offspring and
plays a key role in evolution.
1.2 Vegetative Propagation
2. Reproduction is the means of transmission of The process of growing new plants from vegetative
hereditary material. parts - root, stem or leaf.
• During reproduction the hereditary material The plants produced by vegetative propagation
(DNA) is copied and passed on to next are genetically similar to the parent plant, hence they
generation through gametes. do not produce new varieties and lose vigour when
• The copied DNA is similar, but no identical to grown repeatedly.
parent DNA due to introduction of variations Vegetative propagation may be Natural or Artificial.
during the copying of the DNA. 1. Natural vegetative propagation occurs by roots
• Variations introduced in the DNA at the time (sweet potato, Dahlia, Asparagus, etc.), by stem
of reproduction may be useful, harmful or (ginger, potato, onion, turmeric, etc.), by leaves
neutral. (Bryophyllum, Begonia, etc.) and by bulbils
(Agave, Oxalis, Dioscorea, etc.).
1.1 Modes of Reproduction used by Single Organ- 2. Artificial vegetative propagation is carried out by
isms-Asexual Reproduction stem cutting (rose, sugarcane, lemon, etc.), root
cutting
1. Fission
Tissue culture or micro-propagation is a technique
A unicellular organism may divide into two (Binary of propagating plants by culturing cells or tissues
fission - Amoeba, Paramecium, Leishmania and from growing tips of a plant in a culture medium
bacteria) or more (multiple fission - Plasmodium) (orchids, gladioli, Chrysanthemum, etc.).
identical daughter organisms under favourable and
unfavourable environmental conditions respectively.
2. SEXUAL REPRODUCTION
2. Budding Sexual Reproduction is a mode of reproduction in
The new organism arises as an outgrowth on parent which two parents are involved to give rise to a new
organism (yeast, Hydra). individual. Sexual mode of reproduction in organisms
is evolved to generate more variations the population
3. Spore Formation which ensures the survival of the species.
Fungi such as Rhizopus (bread mould) Mucor,
Penicillium, Aspergillus, etc. form tiny structures 2.1 Sexual Reproduction in Flowering Plants
called spores which give rise to new individuals. Sexual reproduction in flowering plants (angiosperms)
takes place with the help of flowers which contain the
Page 145 How do organisms Reproduce Chap 8

reproductive organs. gamete), associated ducts (vas efferents, epididymis

1. Stamens (male) and carpels (female) are the and vas deferens), accessory reproductive organs
reproductive organs of a flower. (penis and urethra) and accessory reproductive glands
2. Flowers may be uni-sexual having either stamen (seminal vesicles, a pair of Cowper’s glands and a
or carpels (papaya, watermelon, etc.) or bisexual prostate gland).
having both stamens and carpels (Hibiscus, 1. Urethra is a common tube for meant to expel
mustard, etc.). urine and sperm out of the body.
The process of reproduction in plants takes place by: 2. Penis is a muscular and erectile copulatory organ
of man.
1. Pollination
3. Semen is a mixture or mature sperm and secretions
Pollination, which is the process of transfer of pollen of various accessory glands.
from anther to the stigma of flower. It may be Self-
pollination (if pollen grains transfer from the anther 3.3 The Female Reproductive System
to the stigma of the same flower or of another flower The female reproductive system in human beings
of the same plant) or Cross-pollination (if the pollen consists of a pair of ovaries which produce ova (female
grains transfer from the anther of one flower to the gamete), a pair of fallopian tubes and accessory
stigma of another flower of another plant but of the reproductive organs (uterus, vagina and vulva).
same species).
1. Uterus is a pear-shaped, highly muscular hollow
2. Fertilisation structure where development of foetus occurs.
2. Vagina is a short and wide muscular tube which
Fertilisation, which is the fusion of male and female
receives sperm during intercourse or mating and
gametes to form zygote. In angiosperms, double
acts as birth canal during child birth.
fertilisation occurs in which one male gamete fuses
with egg to form zygote and other male gamete fuses 3. Vulva is the external genitalia of human female. It
with two polar nuclei to form endosperm. consists of labia majora, labia minora and clitoris.
1. Fertilisation
2.2 Post-fertilisation Changes
Fertilisation is the fusion of male and female gametes.
Post-fertilisation changes involve development of
In human beings, fertilisation is internal. During
zygote into an embryo within the ovule, development
copulation (mating), sperm are deposited in the
of ovule into seed and development of ovary into fruit.
vagina. They travel to the fallopian tube where the
On getting favourable environmental conditions, seed fusion of sperm and ovum takes place.
germinates to form a small seedling which finally
grows into a plant. 2. Implantation
Implantation is the process of attachment of blastocyst
3. REPRODUCTION IN HUMAN BEINGS (embryo) in the uterine wall.

Human beings are uni-sexual. They show sexual 3. Gestation Period

dimorphism (males and females are visibly different Gestation period is the time period of development of
from each other). embryo in the mother’s uterus. In humans, it lasts for
about 280 days or 40 weeks or 9 months.
3.1 Puberty
Puberty is the age at which reproductive organs 4. Birth of a Child is Called Parturition.
become functional. Generally, boys attain puberty at
the age of 13-14 years, whereas girls reach puberty 3.4 When Egg is Not Fertilised
at the age of 10-12 years. The male sex hormone The endometrium of uterus erodes and the unfertilised
testosterone secreted from the testes and the female ovum comes out of vagina in the form of blood flow
sex hormones estrogen and progesterone secreted from called menstruation or menstrual flow.
ovary start puberty in boys and girls respectively.
3.5 Menstrual Cycle or Menstruation
3.2 The Male Reproductive System
Menstruation usually occurs 14 days after ovulation
The Male Reproductive System in human beings and usually lasts for 3-5 days. If the ovum does not
consists of a pair of testes which produce sperm (male
Page 146 How do organisms Reproduce Chap 8

get fertilised, the menstrual cycle is repeated again OBJECTIVE QUESTIONS

after every 28 days.
1. Menarche is the first menstruation in a girl after
attaining puberty at 10-12 years of age. Menopause 1. Cessation of menstrual cycle in the human female is
is the permanent stoppage of menstruation in a known as
woman which occurs at the age of about 45 years. (a) ovulation (b) puberty
3.6 Reproductive Health (c) menopause (d) maturation
Sol :
Reproductive Health refers to total well-being in
all aspects of reproduction which includes physical,
2. The reproductive life of a woman lasts from hacreemn
emotional, social and behavioural well-being of an
to spauoemen
individual.
(a) reproductive life a woman lasts from menarche to
3.7 Sexually Transmitted Diseases (STD) or Vene- menopause.
real Diseases (b) reproductive life a woman lasts from menarche to
Sexually transmitted diseases (STD) or venereal menopause.
diseases spread by sexual contact with infected (c) reproductive life a woman lasts from chenmare to
persons. These are caused by bacteria, viruses and pausemeno.
protozoans. Common STDs are Gonorrhoea (by the (d) reproductive life a woman lasts from chenmare to
bacterium, Neisseria gonorrhoea, mainly in females), usemenopa.
Syphilis (by the bacterium Treponema pallidum), Sol :
Genital Herpes (by a virus Herpes simplex) Genital
Warts (by human papillomavirus : HPU and Acquired
3. Lower narrow end of uterus is called as
Immune Deficiency Syndrome : AIDS by HIV (Human
Immunodeficiency Virus). (a) urethra (b) cervix
(c) clitoris (d) vulva
3.8 The Family Planning Programme Sol :
The family planning programme is being run by
the government to create awareness in the mass to 4. Other than spirogyra, fragmentation also occurs in
maintain a balance between home economy and size of (a) amoeba (b) hydra
the family including nutrition of the child and of the (c) planaria (d) none of the above
pregnant woman. Sol :

3.9 Contraception
5. Which of the following cell is formed as a product of
Contraception is the avoidance of pregnancy by fertilization?
preventing the fertilisation of ovum. The methods (a) embryo (b) gamete
of contraception include Withdrawal technique,
Barrier methods (Condom - Nirodh, Diaphragm), (c) zygote (d) fruit
Sol :
the Intra-uterine Contraceptive Device : IUCD (Loop
or Coper - T), Chemical methods (Spermicide, Oral
Contraceptives : OCs or Birth Control Pills), and 1. In the list of organisms given below, those that
Surgical methods (Vasectomy in males and Tubectomy reproduce by the asexual method are
in a females). (i) Banana
(ii) Dog
For solutions download NODIA app. (iii) Yeast
(iv) Amoeba
(a) (ii) and (iv) (b) (i), (iii) and (iv)
(c) (i) and (iv) (d) (ii), (iii) and (iv)
Sol : Delhi 2013

For solutions download NODIA app.

Page 147 How do organisms Reproduce Chap 8

2. In a flower, the parts that produce male and female (c) they reproduce only sexually
gametes (germ cells) are (d) they are all multicellular
(a) stamen and anther Sol :
(b) filament and stigma
(c) anther and ovary 8. In Spirogyra, asexual reproduction takes place by
(a) breaking up of filaments into smaller bits
(d) stamen and style
Sol : (b) division of a cell into two cells
(c) division of a cell into many cells
3. Which of the following is the correct sequence of (d) formation of young cells from older cells
events of sexual reproduction in a flower? Sol :
(a) pollination, fertilisation, seedling, embryo
(b) seedling, embryo, fertilisation, pollination 9. The ability of a cell to divide into several cells during
(c) pollination, fertilisation, embryo, seedling reproduction in Plasmodium is called
(a) budding (b) reduction division
(d) embryo, seedling, pollination, fertilisation.
Sol : (c) binary fission (d) multiple fission
Sol : OD 2017

4. Offspring formed by asexual method of reproduction

have greater similarity among themselves because 10. The correct sequence of reproductive stages seen in
(i) asexual reproduction involves only one parent flowering plants is
(ii) asexual reproduction does not involve gametes (a) gametes, zygote, embryo, seedling
(iii) asexual reproduction occurs before sexual (b) zygote, gametes, embryo, seedling
reproduction (c) seedling, embryo, zygote, gametes
(iv) asexual reproduction occurs after sexual
(d) gametes, embryo, zygote, seedling
reproduction Sol : Foreign 2012
(a) (i) and (ii) (b) (i) and (iii)
(c) (ii) and (iv) (d) (iii) and (iv) 11. The number of chromosomes in parents and offsprings
Sol : of a particular species remains constant due to
(a) doubling of chromosomes after zygote formation
5. Characters transmitted from parents to offspring are
(b) halving of chromosomes during gamete formation
present in
(c) doubling of chromosomes after gamete formation
(a) cytoplasm (b) ribosome
(d) halving of chromosomes after gamete formation
(c) golgi bodies (d) genes Sol :
Sol :

12. In Rhizopus, tubular thread-like structures bearing

6. Characters that are transmitted from parents to
sporangia at their tips are called
offspring during reproduction show
(a) filaments (b) hyphae
(a) only similarities with parents
(c) rhizoids (d) roots
(b) only vairations with parents Sol :
(c) both similarities and variations with parents
(d) neither similarities nor variations 13. Vegetative propagation refers to formation of new
Sol : plants from
(a) stem, roots and flowers
7. A feature of reproduction that is common to Amoeba,
(b) stem, roots and leaves
Spirogyra and yeast is that
(c) stem, flowers and fruits
(a) they reproduce asexually
(d) stem, leaves and flowers
(b) they are all unicellular Sol :
Page 148 How do organisms Reproduce Chap 8

14. Factors responsible for the rapid spread of bread 19. In following diagram the parts A, B and C are
mould on slices of bread are sequentially
(i) large number of spores
(ii) availability of moisture and nutrients in bread
(iii) presence of tubular branched hyphae
(iv) formation of round shaped sporangia
(a) (i) and (iii) (b) (ii) and (iv)
(c) (i) and (ii) (d) (iii) and (iv)
Sol :
(a) cotyledon, plumule and radicle
15. Length of pollen tube depends on the distance between (b) plumule, radicle and cotyledon
(a) pollen grain and upper surface of stigma (c) plumule, cotyledon and radicle
(b) pollen grain on upper surface of stigma and ovule (d) radicle, cotyledon and plumule
Sol : Foreign 2013
(c) pollen grain in anther and upper surface of stigma
(d) upper surface of stigma and lower part of style
20. Offspring formed as a result of sexual reproduction
exhibits more variations because
16. Which of the following statements are true for flowers?
(a) sexual reproduction is a lengthy process
(i) Flowers are always bisexual
(ii) They are the sexual reproductive organs (b) genetic material comes from two parents of the
same species
(iii) They are produced in all groups of plants
(iv) After fertilisation they give rise to fruits (c) genetic material comes from two parents of
different species
(a) (i) and (iv) (b) (ii) and (iii)
(d) genetic material comes from many parents
(c) (i) and (iii) (d) (ii) and (iv) Sol :
Sol : Delhi 2016

21. Reproduction is essential for living organisms in order

17. Which among the following statements are true for
to
unisexual flowers?
(a) keep the individual organism alive
(i) They possess both stamen and pistil
(ii) They possess either stamen or pistil (b) fulfil their energy requirement
(iii) They exhibit cross pollination (c) maintain growth
(iv) Unisexually flowers possessing only stamens (d) continue the species generation after generation
cannot produce fruits Sol :
(a) (i) and (iv) (b) (ii), (iii) and (iv)
(c) (iii) and (iv) (d) (i), (iii) and (iv) 22. During adolescence, several changes occur in the
Sol : human body. Mark one change associated with
maturation in boys
18. Which among the following statements are true for (a) loss of milk teeth
sexual reproduction in flowering plants? (b) increase in height
(i) It requires two types of gametes (c) cracking of voice
(ii) Fertilisation is a compulsory event (d) weight gain
(iii) It always results in formation of zygote Sol : OD 2012

(iv) Offsprings formed are clones

(a) (i) and (iv) 23. In human females, an event that reflects onset of
(b) (i), (ii) and (iv) reproductive phase is
(c) (i), (ii) and (iii) (a) growth of body

(d) (i), (iii) and (iv) (b) change in hair pattern

Page 149 How do organisms Reproduce Chap 8

(c) change in voice A B C D

(d) menstruation (a) q s p r
Sol :
(b) p q, s, r,
24. In human males, the testes lie in the scrotum, because (c) r s, p, q
it helps in the (d) r q s p
(a) process of mating Sol :
(b) formation of sperm
(c) easy transfer of gametes 29. Match the column I to column II and select the correct
answer using the codes given below:
(d) all the above
Sol : Foreign 2014
Column I Column II
(A) Amoeba (p) Budding
25. Which among the following is not the function of
testes at puberty? (B) Hydra (q) Regeneration
(a) formation of germ cells (C) Planaria (r) Fission
(b) secretion of testosterone (D) Rhizopus (s) Fragmentation
(c) development of placenta
(E) Spirogyra (t) Spore formation
(d) secretion of estrogen
(a) (i) and (ii) (b) (ii) and (iii)
A B C D E
(c) (iii) and (iv) (d) (i) and (iv)
Sol : Delhi 2013 (a) r p t s q
(b) p q, s, r, t
26. The correct sequence of organs in the male reproductive (c) r s, p, q t
system for transport of sperms is
(d) r q s p t
(a) testis " vas deferens " urethra Sol :
(b) testis " ureter " urethra
(c) testis " urethra " ureter 30. Assertion : Individuals produced by asexual
(d) testis " vas deferens " ureter reproduction are known as clones.
Sol : Reason : They are known as clones because they are
genetically identical.
27. Which among the following diseases is not sexually (a) Both assertion (A) and reason (R) are true and
transmitted? reason (R) is the correct explanation of assertion
(a) syphilis (b) Hepatitis–A (A).
(c) HIV-AIDS (d) Gonorrhoea (b) Both assertion (A) and reason (R) are true but
Sol : reason (R) is not the correct explanation of
assertion (A).
28. Match the column I to column II and select the correct (c) Assertion (A) is true but reason (R) is false.
answer using the codes given below: (d) Assertion (A) is false but reason (R) is true.
Sol :
Column I Column II
(A) Seminal vesicle (p) Latex sheath For solutions download NODIA app.
(B) Urinogenital duct (q) Semen plasma
31. Assertion : Vagina is also called as birth canal.
(C) Condom (r) Protozoan
Reason : During birth, the baby passes through the
(D) Trichomoniasis (s) Corpus spongiosum vagina.
(a) Both assertion (A) and reason (R) are true and
reason (R) is the correct explanation of assertion
Page 150 How do organisms Reproduce Chap 8

(A). 35. Assertion : Characteristics of parental plants can be

(b) Both assertion (A) and reason (R) are true but preserved through asexual reproduction.
reason (R) is not the correct explanation of Reason : Vegetative reproduction involves only
assertion (A). mitosis.
(c) Assertion (A) is true but reason (R) is false. (a) Both assertion (A) and reason (R) are true and
reason (R) is the correct explanation of assertion
(d) Assertion (A) is false but reason (R) is true. (A).
Sol :
(b) Both assertion (A) and reason (R) are true but
reason (R) is not the correct explanation of
32. Assertion : Vasectomy is a surgical method or birth
assertion (A).
control.
Reason : In vasectomy, small portion of oviduct is cut (c) Assertion (A) is true but reason (R) is false.
or tied properly. (d) Assertion (A) is false but reason (R) is true.
Sol :
(a) Both assertion (A) and reason (R) are true and
reason (R) is the correct explanation of assertion
(A). 36. Assertion : Scrotum is present outside the abdominal
(b) Both assertion (A) and reason (R) are true but cavity.
reason (R) is not the correct explanation of Reason : It stores sperms which require a lower
assertion (A). temperature than the normal body temperature.
(c) Assertion (A) is true but reason (R) is false. (a) Both assertion (A) and reason (R) are true and
reason (R) is the correct explanation of assertion
(d) Assertion (A) is false but reason (R) is true. (A).
Sol :
(b) Both assertion (A) and reason (R) are true but
reason (R) is not the correct explanation of
33. Assertion : Amobea reproduces by Binary fission.
assertion (A).
Reason : All unicellular organisms reproduce asexually.
(c) Assertion (A) is true but reason (R) is false.
(a) Both assertion (A) and reason (R) are true and
reason (R) is the correct explanation of assertion (d) Assertion (A) is false but reason (R) is true.
Sol :
(A).
(b) Both assertion (A) and reason (R) are true but
reason (R) is not the correct explanation of 37. Assertion : DNA copying is necessary during
assertion (A). reproduction.
Reason : DNA copying leads to the transmission of
(c) Assertion (A) is true but reason (R) is false.
characters from parents to offspring.
(d) Assertion (A) is false but reason (R) is true. (a) Both assertion (A) and reason (R) are true and
Sol :
reason (R) is the correct explanation of assertion
(A).
34. Assertion : Surgical methods are most effective
(b) Both assertion (A) and reason (R) are true but
methods of contraception.
reason (R) is not the correct explanation of
Reason : Surgical method blocks gametes transport assertion (A).
and hence prevent fertilisation.
(c) Assertion (A) is true but reason (R) is false.
(a) Both assertion (A) and reason (R) are true and
reason (R) is the correct explanation of assertion (d) Assertion (A) is false but reason (R) is true.
Sol :
(A).
(b) Both assertion (A) and reason (R) are true but
reason (R) is not the correct explanation of 38. Assertion : An embryo is formed from fertilized egg.
assertion (A). Reason : A monocot embryo comprises embryonal
axis with two cotyledons.
(c) Assertion (A) is true but reason (R) is false.
(a) Both assertion (A) and reason (R) are true and
(d) Assertion (A) is false but reason (R) is true. reason (R) is the correct explanation of assertion
Sol :
(A).
Page 151 How do organisms Reproduce Chap 8

(b) Both assertion (A) and reason (R) are true but 42. Assertion : In human male, testes are extra abdominal
reason (R) is not the correct explanation of which are present inside scrotum.
assertion (A). Reason : Scrotum has a relatively lower temperature
(c) Assertion (A) is true but reason (R) is false. needed for the production and storage of sperms.
(d) Assertion (A) is false but reason (R) is true. (a) Both assertion (A) and reason (R) are true and
Sol : reason (R) is the correct explanation of assertion
(A).
39. Assertion : Unisexual flowers have separate male and (b) Both assertion (A) and reason (R) are true but
female flowers whereas a typical monocot embryo reason (R) is not the correct explanation of
comprises an embryonal axis with single cotyledon. assertion (A).
Reason : Cucumber, pumpkin and water melon are (c) Assertion (A) is true but reason (R) is false.
example of unisexual flowers. (d) Assertion (A) is false but reason (R) is true.
(a) Both assertion (A) and reason (R) are true and Sol :
reason (R) is the correct explanation of assertion
(A). 43. Assertion : At puberty, in boys, voice begins to crack
(b) Both assertion (A) and reason (R) are true but and thick hair grows on face.
reason (R) is not the correct explanation of Reason : At puberty, there is decreased secretion of
assertion (A). testosterone in boys.
(c) Assertion (A) is true but reason (R) is false. (a) Both assertion (A) and reason (R) are true and
(d) Assertion (A) is false but reason (R) is true. reason (R) is the correct explanation of assertion
Sol : (A).
(b) Both assertion (A) and reason (R) are true but
40. Assertion : Double fertilisation is unique to reason (R) is not the correct explanation of
angiosperms. assertion (A).
Reason : Triple fusion occurs in both fertilization. (c) Assertion (A) is true but reason (R) is false.
(a) Both assertion (A) and reason (R) are true and (d) Assertion (A) is false but reason (R) is true.
reason (R) is the correct explanation of assertion Sol :
(A).
(b) Both assertion (A) and reason (R) are true but
reason (R) is not the correct explanation of
assertion (A). ONE MARK QUESTIONS
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
Sol : 44. Give an example of a flower which contains both
stamens and carpels.
Sol : Delhi 2018
41. Assertion : Sexual reproduction increases genetic
diversities and plays a role in origin of new species.
45. What is parthenogenesis?
Reason : Sexual reproduction involves formation of Sol : OD 2017

gametes and fusion of gametes.

(a) Both assertion (A) and reason (R) are true and 46. What is DNA?
reason (R) is the correct explanation of assertion Sol : OD 2016, Delhi 201

(A).
(b) Both assertion (A) and reason (R) are true but 47. Give an example of organism where binary fission
reason (R) is not the correct explanation of takes place.
assertion (A). Sol : Delhi 2017

(c) Assertion (A) is true but reason (R) is false.

48. Name an organism in which multiple fission takes
(d) Assertion (A) is false but reason (R) is true.
Sol : place.
Sol : Delhi 2016, Delhi 2012
Page 152 How do organisms Reproduce Chap 8

49. What happens when a Planaria gets cut into two 63. Name the male and female gonads in human beings.
Sol : Delhi 2017
pieces?
Sol : Foreign 2017

64. What name is given to primary sex organs?

Sol : Delhi 2016
50. Name three methods by which plant reproduces by
stems.
Sol : Delhi 2016
65. How many fallopian ducts are there in female
reproductive system?
Sol : Foreign 2017
51. Name two examples where budding takes place.
Sol : SQP 2017, Delhi 2013

66. Name the male and female gametes in animals.

Sol : SQP 2016
52. Name the part of Bryophyllum where the buds are
produced for vegetative propagation.
Sol : OD 2016
67. What happens when vas deferens gets blocked?
Sol : OD 2015, Delhi 2014

53. Name two STDs.

Sol : Comp. 2017
68. What is the function of petals?
Sol : OD 2014

54. What is the function of sepals?

Sol : OD 2016
69. Name any two hermaphrodite animals.
Sol : Delhi 2015

55. Name the life process of an organism that helps in the

growth of its population. 70. Name two types of openings of female reproductive
Sol : Delhi 2017
system.
Sol : Delhi 2014, Delhi 2014

56. Give three examples of organisms which reproduce by

spore formation. 71. What is the function of DNA?
Sol : Delhi 2016 Sol : Foreign 2015

57. Name an algae which reproduces by the process of 72. How do different organisms get different body designs?
fragmentation. Sol : Comp. 2014

Sol : Foreign 2017

73. Where is DNA found in a cell?

58. Give the respective scientific terms used for studying Sol : SQP 2015

(i) The mechanism by which variations are created

and inherited and 74. When an organism bears both the types of sex organs,
(ii) The development of new type of organisms from what name is given to such organism?
Sol : SQP 2014
the existing ones.
Sol : OD 2016

75. Name two multicellular organisms which reproduce by

59. Where are the male and female gametes produced in asexual reproduction.
Sol : OD 2015
flowers?
Sol : Comp 2015

76. Name the process by which organisms produce new

60. Name the causative organism of AIDS. young ones?
Sol : Comp 2016 Sol : OD 2013

61. Give an advantage of vegetative propagation. 77. How do unicellular organisms reproduce?
Sol : OD 2017 Sol : Delhi 2015

62. How many vas deferences are there in male 78. Name few plants which reproduce by layering.
Sol : Delhi 2014
reproductive system?
Sol : Foreign 2016
Page 153 How do organisms Reproduce Chap 8

79. What is the product of fertilisation? 95. What is the expanded form of AIDS ?
Sol : Foreign 2015, Delhi 2011 Sol : Comp. 2013

80. Name the agents that help in cross-pollination. 96. How do we know that two different organisms belong
Sol : Foreign 2014
to the same species ?
Sol : OD 2013

81. How is the AIDS prevented?

Sol : Comp 2015
97. By which part bryophyllum reproduces ?
Sol : OD 2012, Delhi 2010

82. An organism produces two different gametes which

fuse to form new individual. What do you call this 98. Where is embryo sac present in the flower ?
Sol : Delhi 2013
type of reproduction?
Sol : Comp 2014

99. What is the primary sex organ in human female?

Sol : Delhi 2012
83. Why do organisms reproduce?
Sol : OD 2015

100. Explain how do organisms create an exact copy of

84. Name the male and female reproductive parts of themselves.
Sol : Foreign 2013
flower.
Sol : OD 2014

101. Why cannot fertilisation take place in flowers if

85. What is the other name of tissue culture? pollination does not occur?
Sol : Delhi 2015 Sol : Comp 2011

86. List any two conceptive methods practiced only by 102. Out of the following plants which two plants are
women. reproduced by vegetative propagation?
Sol : Delhi 2014
Jasmine, Wheat, Mustard, Banana
Sol : OD 2013

87. Write two modes of reproduction.

Sol : Foreign 2015
103. Leaves of Bryophyllum fallen on the ground to produce
new plants. Why ?
88. What is the reproductive organ in higher plants? Sol : Comp 2017
Sol : Foreign 2014, Delhi 2010

104. State in brief two functions of copper-T used by some

89. Name the body part where fertilisation occurs in women.
human female ? Sol : OD 2011
Sol : OD 2012

105. List any two reasons for adopting contraceptive

90. Name the types of nucleic acids. methods.
Sol : Delhi 2013 Sol : Delhi 2011

For solutions download NODIA app.

91. Name parts of a stamen.
Sol : Delhi 2012

92. What does involve at the most basic level of

reproduction?
Sol : Foreign 2013
TWO MARKS QUESTIONS

93. Where are the pollen grains produced? 106. You soak seeds of bean and observe them after 2-3
Sol : Foreign 2012
days. What will be your observations?
Sol : Delhi 2019

94. Name an IUCD ?

Sol : SQP 2013
Page 154 How do organisms Reproduce Chap 8

107. With the help of diagram show the different stages of 119. (a) Write full form of DNA.
binary fission in Amoeba. (b) Why are variations essential for the species?
Sol : OD 2017 Sol : Delhi 2016

108. How do following organisms reproduce by asexual 120. (a) What is vegetative propagation ?
reproduction? (b) Write any two advantages of practising this
(a) Hydra method.
(b) Planaria or
(c) Malarial parasite List two advantages of vegetative propagation.
Sol : Foreign 2017
(d) Potato
Sol : OD 2016, Delhi 2011

121. What are the various methods of asexual reproduction?

Sol : Foreign 2016, Delhi 2012
109. What is the basic event in reproduction?
Sol : Delhi 2017

122. Leaves of Bryophyllum fallen on the ground produce

110. What is grafting? What do the terms ‘stock’ and new plants, whereas the leaves of Jasmine do not.
‘scion’ mean in grafting? Why ?
Sol : Delhi 2016 Sol : SQP 2017

111. What will happen when : 123. What are the disadvantages of natural vegetative
(a) A mature Spirogyra filament attains considerable propagation?
Sol : Comp 2016
length?
(b) Planaria gets cut into two pieces?
Sol : OD 2017 124. The organisms formed by asexual reproduction are
considered as clones. Why? State the advantage of
112. (a) Trace the path of sperms from where they are sexual reproduction over asexual reproduction.
Sol : OD 2017
produced in human body to the exterior.
(b) Write the functions of secretions of prostate gland
and seminal vesicles in humans. 125. What is meant by pollination? Name and differentiate
Sol : Foreign 2016, Delhi 2011 between the two modes of pollination in flowering
plants.
Sol : OD 2016

113. Variations are important for the survival of species

overtime. Justify this statement with reasons.
Sol : SQP 2017 126. Mention the role of sex hormones in human
reproduction.
Sol : Delhi 2017

114. Why is DNA copying necessary during reproduction ?

Sol : OD 2013
127. Name the female reproductive part of a flower. Which
part of a flower develops into a seed and a fruit? Where
115. Mention the two functions of human testes. are the male germ cell and female gamete produced
Sol : Comp. 2016
in a flower?
Sol : OD 2015, Delhi 2012

116. Are the two cells formed in reproduction are identical?

Sol : OD 2017
128. Explain external and internal fertilisation.
Sol : Delhi 2016

117. Draw a labelled diagram of human male reproductive

system. 129. What are sexually transmitted diseases? Name few
Sol : OD 2016
of them.
Sol : Foreign 2017

118. Draw a labelled diagram of a human female

For solutions download NODIA app.
reproductive system.
Sol : Delhi 2017
Page 155 How do organisms Reproduce Chap 8

130. How is the amount of DNA maintained in each 141. Name the parts A, B and C shown in the given
generation? diagram above and, state one function of each part.
Sol : OD 2016 Sol : Delhi 2014, Delhi 2014

131. What are the functions of testis in the human male

reproductive system? Why are these located outside
the abdominal cavity? Who is responsible for bringing
about changes in appearance seen in boys at the time
of puberty?
Sol : Foreign 2015, Delhi 2012

132. List the advantages of sexual reproduction.

Sol : OD 2014

133. How does the process of seed germination take place Sol :
in plants? Describe in brief.
Sol : Delhi 2015
142. (a) Name two animals which reproduce asexually.
(b) What are the male and female gonads in human
134. (a) Name an organism in which binary fission occurs beings known as?
in a definite orientation. Sol : Foreign 2015

(b) Draw a neat diagram of a germinating seed and

label on it the following : 143. What is placenta? State its any two roles during
Cotyledon, Plumule, Radicle. pregnancy.
Sol : Foreign 2014 Sol : Delhi 2014

135. In a bisexual flower inspite of the young stamens 144. In what respect is the human male gamete different
being removed artificially, the flower produces fruit. from the female gamete?
Sol : Comp 2015
Give reasons.
Sol : Foreign 2014

145. State the significance of human testis being located

136. How does the process of budding differ from the in the scrotum.
Sol : Delhi 2014
process of spore formation?
Sol : SQP 2015

146. (a) List two reproductive parts of a flower.

137. What are sexually transmitted diseases? Name an (b) How is a unisexual flower different from a bisexual
STD which damages the immune system of human flower? State in brief.
body. Sol : OD 2015

Sol : Comp. 2014

147. Define reproduction. How does it help in providing

138. Compare the vegetative propagation in Bryophyllum stability to the population of species?
and money plant. Sol : OD 2014

Sol : OD 2015, Delhi 2013

148. In tobacco plant, the male gametes have 24

139. List four points of significance of reproductive health in chromosomes. State the number of chromosomes in
a society. Name any two areas related to reproductive (i) egg nucleus, (ii) zygote, (iii) endosperm and (iv)
health which have improved over the past 50 years in leaf cell.
our country. Sol : Delhi 2015

Sol : OD 2014

149. (a) Surgical methods can be used to create a block

140. Protozoans reproduce by binary fission as well as by in the reproductive system for contraceptive
multiple fission. In your opinion, which process is purposes. Name such parts where blocks are
better and why?
Sol : Delhi 2015
Page 156 How do organisms Reproduce Chap 8

created in : 159. (a) Name the parts 1 to 5 of human female

(i) males reproductive system.
(ii) females (b) Name the part in which fertilization takes place in
(b) State any two reasons for using contraceptive this system.
devices.
Sol : Delhi 2014

150. What are the advantages and disadvantages of asexual

reproduction?
Sol : OD 2015

151. State the mode of reproduction in following organisms:

Earthworm, Frog, Rhizopus, Plasmodium
Sol : Foreign 2014

152. Name the sex hormones secreted by male and female

sex organs in human beings. State one function of Sol : SQP 2012, Delhi 2011

each.
Sol : OD 2013, Delhi 2010
160. Pre-natal sex determination has been prohibited by
law. State two reasons.
153. (a) Draw a neat diagram of female reproductive Sol : OD 2013

system in human being and label :

(i) the part which secretes ova. 161. What is meant by pollination? List its two types.
(ii) the part where implantation takes place. State any two agents which help in pollination.
Sol : OD 2012
(b) What happens if the fallopian tube is blocked?
Sol : OD 2012

162. (a) How do the oral pills function as contraceptives ?

154. In a sexually reproducing plant, what happens to (b) The use of these pills may be harmful. Why ?
zygote formed after fertilization? State in brief. Sol : Foreign 2012
Sol : Delhi 2013

163. (a) Name the parts of the flower which ripen to form
155. (a) Give reason : regeneration is not the same as fruit and seed.
reproduction. or
(b) State the mode of asexual reproduction in What will happen to ovary and ovule after
Plasmodium. fertilization in angiosperm plants?
Sol : OD 2013
(b) In the following diagram label A and B.

156. (a) What is the site of implantation and development

of young one in human female ?
(b) Mention two advantages of using mechanical
barriers during sexual act.
Sol : Foreign 2013

157. What is regeneration of an organism? Describe with Sol : Comp 2013, Delhi 2011

a neat diagram the different steps of regeneration in

Planaria. 164. What is multiple fission ? How does it occur in an
Sol : SQP 2012
organism ? Explain briefly. Name one organism which
exhibits this type of reproduction.
158. How does Rhizopus multiply by spores? Explain in Sol : Delhi 2012

brief. Sketch neat labelled diagram of this method.

Sol : OD 2012, Delhi 2010 For solutions download NODIA app.
Page 157 How do organisms Reproduce Chap 8

165. (a) Identify the asexual method of reproduction in 170. Distinguish between pollination and fertilisation.
each of the following organisms : Mention the site and the product of fertilisation in
(i) Rose, (ii) Yeast, (iii) Planaria a flower.
Sol : OD 2019
(b) What is fragmentation? Name a multicellular
organism which reproduces by this method.
Sol : OD 2013, Delhi 2011 171. (a) Budding, fragmentation and regeneration, all
are considered as asexual mode of reproduction.
166. In the diagram of human male reproductive system Why?
given below : (b) With the help of neat diagrams, explain the
(a) Label parts A and B. process of regeneration in Planaria.
Sol : OD 2019, Delhi 2015
(b) Name the hormone produced by organ ‘X’. What
is the role of this hormone in the human male ?
172. Our government launches campaigns to provide
(c) Mention the name of substances that are
information about AIDS prevention, testing and
transported by tubes (i) C, and (ii) D.
treatment by putting posters, conducting radio shows
and using other agencies of advertisements.
To which category of diseases AIDS belongs ? Name
and explain. What is its causative organism ? Also
give two more examples of such diseases.
Sol : SQP 2018

173. Draw a labelled diagram in proper sequence to show

budding in hydra.
Sol : OD 2019

174. A student observed a permanent slide showing

asexual reproduction in yeast. Draw diagrams of the
observations he must have made from the slide. Name
the process also.
or
Sol : Comp 2013 A student is viewing under a microscope a permanent
slide showing various stages of asexual reproduction by
167. Which kind of contraceptive method prevents STDs budding in yeast. Draw diagram of what he observes
and how ? in proper sequence.
Sol : Comp 2012, Delhi 2009 Sol : Delhi 2018

175. State one function of each of the following parts of

human male reproductive system :
THREE MARKS QUESTIONS (i) vas deferens
(ii) testis
(iii) prostate gland
Sol : OD 2016, Delhi 2012
168. Name the process of reproduction observed in
yeast. Design an activity to observe this mode of
reproduction in a school laboratory. Name one more 176. Name the process by which an amoeba reproduces.
organism which reproduces by this mode. Draw the various stages of its reproduction in a
Sol : Delhi 2020
proper sequence.
Sol : Delhi 2018

169. What is carpel? Write the function of its various parts.

Sol : OD 2019
177. (a) How many eggs are produced every month
by either of the ovaries in a human female ?
For solutions download NODIA app. Where does fertilization take place in the female
Page 158 How do organisms Reproduce Chap 8

reproductive system ? 185. How do organisms, whether reproduced asexually or

(b) What happens in case the eggs released by the sexually maintain a constant chromosome number
ovary are not fertilized? through several generations? Explain with the help of
Sol : OD 2017
suitable example.
Sol : OD 2016

178. Name those parts of a flower which serve the same

function as the following do in the animal : 186. (a) Explain the process of regeneration is planaria.
(i) Testis (b) How is regeneration different from reproduction?
Sol : Delhi 2017
(ii) Ovary
(iii) Eggs
(iv) Sperms 187. Define the following processes of asexual reproduction.
Sol : Delhi 2017 (a) Spore formation
(b) Regeneration
179. Suggest three contraceptive methods to control the (c) Multiple fission
size of human population. Mention two factors that Sol : Delhi 2016, OD 2011

determine the size of population.

Sol : Delhi 2016, OD 2014
188. (a) Why is vegetative propagation practised for
growing some types of plants ?
180. How do the following organisms reproduce by asexual (b) Name the different parts of a flower that has germ
methods ? cells.
(a) Euglena (c) List any two agents of pollination.
(b) Spirogyra Sol : Foreign 2017

(c) Ginger
(d) Chrysanthemum 189. State in brief the function of the following organs in
(e) Strawberry the human female reproductive system :
(f) Mango (a) Ovary
Sol : Comp 2017 (b) Fallopian tube
(c) Uterus
Sol : Foreign 2016
181. Write one main difference between asexual and sexual
mode of reproduction. Which species is likely to
have comparatively better chances of survival—the 190. Define the two main methods of reproduction in living
one reproducing asexually or the one reproducing organisms.
Sol : Comp 2017
sexually? Give reasons to justify your answer.
Sol : Foreign 2016

191. List six specific characteristics of sexual reproduction.

Sol : Delhi 2016
182. Explain the term ‘Regeneration’ as used in relation
to reproduction of organisms. Describe briefly how
regeneration is carried out in multicellular organisms 192. (a) What is the difference between self-pollination
like Hydra. and cross-pollination ?
Sol : SQP 2015
(b) What happens to the pollen which falls on a
suitable stigma ? Explain.
183. (a) Explain the terms : Sol : OD 2015

(i) implantation, (ii) placenta

For solutions download NODIA app.
(b) What is the average duration of human pregnancy?
Sol : Comp. 2016

193. (i) What is vegetative propagation ?

184. (a) List three distinguishing features between sexual (ii) What methods you will use for growing jasmine
and asexual types of reproduction. and rose plants ?
Sol : Delhi 2014, OD 2010
(b) Explain why variations are observed in the
offsprings of sexually reproducing organisms ?
Sol : OD 2017
Page 159 How do organisms Reproduce Chap 8

194. (a) In the given figure name the parts marked 1 to 6: 198. Differentiate between :
(a) Plumule and radicle
(b) Pollination and fertilization
Sol : SQP 2016, OD 2014

199. Define pollination. Explain the different types of

pollination.’ List two agents of pollination? How does
suitable pollination lead to fertilization?
Sol : SQP 2019

200. A student wants to germinate dicot seeds. Write the

four steps in correct sequence that will help him to
(b) Differentiate between self-pollination and cross- perform the experiment in the right way.
Sol : Comp 2019
pollination.
Sol : Delhi 2014

201. What are the aspects included in reproductive health?

Sol : Foreign 2014
195. A part of the male reproductive system is shown
below. Study the diagram and answer the questions
that follow. 202. (a) How will an organism be benefited if it reproduces
through spores ?
(b) How is regeneration different from fragmentation?
Sol : Delhi 2016, OD 2013

203. Write the two causes of human population explosion.

Explain with the help of suitable examples how this
explosion can be checked.
Sol : OD 2017

204. Answer the following questions :

(a) What happens if an egg is not fertilized?
(b) Why do we need to adopt contraceptive measures?
(a) Two parts have been incorrectly labelled. Identify (c) Name one bacterial and one viral sexually
them. transmitted disease.
Sol : Delhi 2015
(b) Give the function of urethra.
(c) Which hormone is released by testis?
Sol : SQP 2015, OD 2010

196. (a) State any two changes seen in boys at the time of FIVE MARKS QUESTIONS
puberty.
(b) Define fertilization and implantation.
205. (a) “Use of a condom is beneficial for both the sexes
(c) State the role of ovary and fallopian tube in
involved in a sexual act.” Justify this statement
human body.
Sol : Comp 2015 giving two reasons.
(b) How do oral contraceptive help in avoiding
197. (a) Write the functions of the following parts in pregnancies ?
human female reproductive system : (c) What is sex selective abortion? How does it affect
(i) Ovary, (ii) Oviduct, (iii) Uterus. a healthy society ? (State any one consequence)
Sol : OD 2020
(b) Write the structure and function of placenta.
Sol : Foreign 2015, OD 2012
206. (i) Describe the various steps involved in the process
Page 160 How do organisms Reproduce Chap 8

of binary fission with the help of a diagram. 212. (a) Identify the given diagram. Name the parts 1 to 5.
(ii) Why do multicellular organisms use complex way
of reproduction ?
Sol : Delhi 2020

207. (i) Describe the role of prostate gland, seminal

vesicle and testes in the human male reproductive
system.
(ii) How is the surgical removal of unwanted
pregnancies misused?
(iii) Explain the role of oral contraceptive pills in
preventing conception.
Sol : OD 2020

(b) What is contraception? List three advantages of

208. (a) Draw a diagram showing germination of pollen on adopting contraceptive measures.
Sol : Delhi 2019
stigma of a flower and mark on it the following
organs/parts :
213. (a) Draw the diagram of female reproductive system
(i) Pollen Grain
and match and mark the part(s) :
(ii) Pollen tube
(i) Where block is created surgically to prevent
(iii) Stigma fertilization.
(iv) Female germ cell (ii) Where Copper-T is inserted?
(b) State the significance of pollen tube. (iii) Inside which condom can be placed.
(c) Name the parts of flower that develop after (b) Why do more and more people prefer to use
fertilisation into condoms? What is the principle behind use of
(i) Seed condoms?
(ii) Fruit Sol : 2019
Sol : OD 2020, SQP 2015

214. (a) What is variation? How is variation created in a

209. (a) Suggest any two categories of contraceptive population? How does the creation of variation in
methods to control the size of human population a species promote survival?
which is essential for the prosperity of a country. (b) Explain how, offspring and parents of organisms
Also explain about each method briefly. reproducing sexually have the same number of
(b) Name two bacterial and two viral infections each chromosomes.
that can get sexually transmitted. Sol : SQP 2018, OD 2015

(c) List two advantages of using condom during

sexual act. 215. (a) Draw a neat labelled diagram of pistil showing
Sol : SQP 2020, OD 2016
germination of pollen on stigma.
(b) Give the functions of :
210. (a) Draw a diagram to show spore formation in (i) Stigma
Rhizopus. (ii) Ovary
(b) With the help of an example differentiate between (c) State in brief the formation of seed in a flower.
the process of Budding and Fragmentation. Sol : SQP 2017, OD 2011

(c) Why is vegetative propagation practiced for

growing some type of plants? 216. (a) Write the function of following parts in human
Sol : Comp. 2020
female reproductive system :
(i) Ovary (ii) Oviduct (iii) Uterus
211. Define the term pollination. Differentiate between
(b) Describe in brief the structure and function of
self pollination and cross pollination. What is the
placenta.
significance of pollination? Sol : Delhi 2018
Sol : OD 2020, OD 2014
Page 161 How do organisms Reproduce Chap 8

217. Explain budding. 223. (a) In the given figure name the parts marked 1 to 6:
or
How does Hydra reproduce? Explain in brief with the
help of a labelled diagram.
Sol : Delhi 2017

218. (a) With the help of diagram show asexual

reproduction in Rhizopus.
(b) How is this method advantageous for Rhizopus?
(c) How is mode of reproduction in unicellular
organisms differ from multicellular organisms?
Sol : Foreign 2017, OD 2016

219. (a) Sketch a neat diagram of longitudinal section of

flower showing fertilization of pollen on stigma
and label on it the following :
(i) Pollen grain
(ii) Male germ cell (b) Differentiate between pollination and fertilization.
Sol : OD 2016, OD 2014
(iii) Female germ cell
(iv) Ovary
224. (a) Draw a neat diagram to show fertilization in a
(b) What does a seed contain? flower and label on it the following parts :
Sol : Foreign 2016
(i) Stigma
(ii) Pollen tube
220. (a) Draw the diagram of a flower to show its male and
female reproductive parts. Label the following (iii) Ovary
parts in it : State the function of pollen tube.
(i) Ovary (b) List in tabular form any two differences between
(ii) Anther a male gamete and a female gamete.
Sol : OD 2017
(iii) Filament
(iv) Stigma
225. Describe different parts of a bisexual flower.
(b) How does fusion of male and female gametes take Sol : SQP 2014, Delhi 2013, OD 2007

place in plants?
Sol : Comp. 2016, OD 2013
For solutions download NODIA app.

221. (a) Differentiate between germination and 226. (a) Draw a neat diagram of longitudinal section of
fertilization. a flower showing the fertilization of pollen on
(b) State in brief the functions of the following parts stigma and label on it the following parts :
of the human male reproductive system : (i) Male germ-cell
(i) Scrotum (ii) Female germ-cell
(ii) Testes (iii) Ovary
(iii) Vas deferens (iv) Pollen tube
Sol : Foreign 2017, OD 2012
(b) “Fertilization will not occur without pollination.”
Justify this statement.
222. (a) Differentiate between pollen grain and ovule. Sol : Delhi 2017, OD 2016

(b) State in brief the functions of the following parts

of the human female reproductive system : 227. (a) Sketch a neat diagram showing longitudinal
(i) Ovary section of flower and label on it.
(ii) Fallopian tube (i) Stigma
(iii) Uterus (ii) Ovary
Sol : Foreign 2016
(iii) Filament
Page 162 How do organisms Reproduce Chap 8

(iv) Sepal (i) Vas deferens

(b) What does ovary of a plant contain? (ii) Prostate glands
Sol : Delhi 2016
(iii) Seminal vesicle, and
(iv) Testis
228. (a) Draw a longitudinal section of a flower and label (b) Why are the testes situated outside the abdominal
the following parts : cavity?
(i) Part that produces pollen grain. or
(ii) Part that transfers male gametes to the (a) Draw a neat diagram of human male reproductive
female gametes. system and label on it the following parts :
(iii) Part that is sticky to trap the pollen grain. (i) Vas deferens
(iv) Part that develops into a fruit. (ii) Seminal vesicle
(b) Differentiate between pollination and fertilisation. (iii) Prostate gland
Sol : Comp 2017, OD 2013
(iv) Testis
229. What is vegetative propagation? Briefly describe (b) Name the male hormone and write its function.
various methods of vegetative propagation. or
Sol : OD 2015
(a) Draw a neat diagram of female reproductive
system and label on it the following parts :
230. (a) Draw a sectional view of human female (i) Oviduct
reproductive system and label the following parts: (ii) Cervix
(i) Where the development of egg occurs (iii) Vagina
(ii) Where fertilization takes place. (iv) Uterus
(b) Describe the changes the uterus undergoes : (b) State any two functions of human ovary.
Sol : Delhi 2015, OD 2013
(i) to receive the zygote
(ii) If zygote is not formed.
Sol : Comp 2016 232. Briefly describe the female reproductive system in
human beings.
Sol : Delhi 2014, OD 2011
231. Briefly describe the male reproductive system in
human beings.
or 233. Define the terms :
(a) Draw a neat diagram of human male reproductive (i) Syngamy
system and label on it the following parts : (ii) Triple fusion
(i) Prostate gland (iii) Implantation
(ii) Seminal vesicle (iv) Placenta
(iii) Testis (v) Gestation.
Sol : Foreign 2015, OD 2009
(b) State the function of testis.
or
234. Draw a neat diagram of the human female reproductive
(a) Mention the role of following organs of human system and label the parts which perform the following
male reproductive system : functions :
(i) Testis (a) Production of eggs
(ii) Scrotum (b) Site of fertilization
(iii) Vas deferens (c) Site of implantation
(iv) Prostate glands (d) Entry of sperms
(b) State the reason why testes are located outside What happens when the egg is not fertilized ?
the abdominal cavity. Sol : SQP 2015

or
(a) Sketch a neat diagram showing male reproductive For solutions download NODIA app.
system in human beings and label on it the
following :
Page 163 How do organisms Reproduce Chap 8

235. (a) Name the parts labelled — A, B, C and D in the 238. What are the three categories of contraceptive
given diagram. methods? Write briefly about each.
Sol : Foreign 2015, OD 2010

239. (a) Sketch a neat diagram of female reproductive

system in human beings and label on it :
(i) Fallopian tube
(ii) Ovary
(iii) Uterus
(iv) Cervix
(b) How do mechanical barrier devices prevent
pregnancy?
Sol : Delhi 2014

(b) Name the parts associated with :

240. What is placenta? Describe its structure. State its
(i) fertilization
functions in case of pregnant human female.
(ii) production of an egg Sol : OD 2015

(c) What happens to the lining of the uterus :

(i) before release of fertilized egg? 241. Draw a neat diagram of the human male reproductive
(ii) if no fertilization occurs? system and label the parts performing the following
Sol : SQP 2014
function :
(a) Production of sperms.
236. (a) Draw a neat labelled diagram of human female (b) Gland which provides fluid.
reproductive system. (c) Provides low temperature for the formation of
(b) Name one organ each in the body of male and sperms.
female reproductive system that plays a role of (d) Common passage for sperms and urine.
endocrine gland along with the production of
Name a sexually transmitted disease and a method
germ cells. Name one hormone in each case.
to avoid it.
(c) Name the part where the fertilization of gametes Sol : Foreign 2014

takes place and also the place where the fertilized

egg is implanted.
Sol : OD 2014, Comp. 2012 242. (a) Which device prevents implantation by irritating
the lining of uterus ?
(b) What could be the possible reason for declining
237. (a) In the given figure label the parts A, B, C and D
female : male sex ratio in our country? Suggest
and state in brief the functions of each of these
two measures to achieve 1:1 ratio.
parts :
(c) Name those parts of a flower which serve the same
function as the following do in animals :
(i) Testis
(ii) Ovary
(iii) Eggs
(iv) Sperms
Sol : Comp 2014

243. (a) Draw a neat diagram of the reproductive system

of a human female and label on it the following :
(i) Reproductive part that produces the female
hormone.
(b) Name two surgical methods of birth control.
Sol : Delhi 2015 (ii) Site of fertilization.
(iii) Organ where growth and development of the
For solutions download NODIA app. embryo takes place.
Page 164 How do organisms Reproduce Chap 8

(b) How does the growing embryo meet with its is the process by which organisms increase their
nutritional requirements? population. The process of sexual maturation for
(c) What happens if the ovum is not fertilized? reproduction is gradual and takes place while general
(d) Mention a contraceptive method that can be used body growth is still going on. Some degree of sexual
by the human female. maturation does not necessarily mean that the mind
Sol : Comp 2015 or body is ready for sexual acts or for having and
bringing up children. Various contraceptive devices
are being used by human beings to control the size of
population.
(i) List two common signs of sexual maturation in
boys and girls.
244. (a) Draw a neat and labelled diagram of female (ii) What is the result of reckless female foeticide ?
reproductive system. (iii) Which contraceptive method changes the
(b) Give the function of the following : hormonal balance of the body ?
(i) Pollen tube (iv) Write two factors that determine the size of a
(ii) Ovary population.
Sol : Delhi 2020
(c) List any two changes observed in the body of a
female during puberty.
Sol : SQP 2015, Comp. 2013 248. Answer given questions on the basis of your
understanding of the following paragraph and the
245. (a) Name the female reproductive part of a flower. related studies concepts.
Draw diagram of its longitudinal section depicting Figure given below which shows monthly changes
the process of fertilization of pollen on stigma and in the human ovary during the reproductive cycle.
label on it the following : Study this related figure and answer the questions
(i) Male germ cell that follow.
(ii) Female germ cell
(iii) Ovary
(b) What happens to the following parts after
fertilization?
(i) Ovum
(ii) Ovary
(iii) Ovule
(iv) Sepals and petals
Sol : OD 2014

246. Explain the term fission used in relation to

reproduction.
Sol : Delhi 2014

(i) Which of the following statements is correct

regarding the labelled structures?
(a) Before puberty, only structure T undergoes
CASE BASED QUEATIONS meiosis.
(b) The hormone produced by structure R
stimulates the pituitary gland to secrete
247. Answer given questions on the basis of your
luteinsing hormone.
understanding of the following paragraph and the
related studies concepts. (c) The hormone produced by structure S is
The growing size of the human population is a cause of responsible for the development of female
concern for all people. The rate of birth and death in a secondary sexual characters.
given population will determine its size. Reproduction (d) The hormone produced by P and Q stimulates
Page 165 How do organisms Reproduce Chap 8

the proliferation of the endometrial lining of

the uterine wall.
(ii) The formation of T begins in female
(a) at birth (b) before birth
(c) after puberty (d) none of these
(iii) What is term used for release of T?
(iv) Which hormone is secreted by R?
Sol :

249. Answer given questions on the basis of your

understanding of the following paragraph and the (i) Name any two bacterial diseases that are caused
related studies concepts. due to unprotected sex.
(ii) In what a pill helps in preventing pregnancy?
(iii) What is vasectomy?
(iv) What are the common side-effects of using
contraceptive pills?
Sol :

251. Answer given questions on the basis of your

understanding of the following paragraph and the
related studies concepts.
Reproduction in human beings is by sexual
reproduction where both the male and female gametes
fertilise to give rise to an embryo. The fertilization
of the human embryo occurs inside the body of the
female.
(i) The type of reproduction shown in the figure is
(a) budding (b) fragmentation
(c) regeneration (d) fission
(ii) Which of the following is correct example of the
process shown in given figure?
(a) Hydra (b) Planaria
(c) Amoeba (d) Both (a) and (b)
(iii) How regeneration is carried out?
(iv) Name any two type of asexual reproduction.
Sol :
(i) Name the part of the male reproductive system
For solutions download NODIA app.
where the formation of sperms takes place.
(ii) What is the placenta?
250. Answer given questions on the basis of your
(iii) What is the other name of the oviduct?
understanding of the following paragraph and the
related studies concepts. (iv) Define the term implantation.
Sol :
The sexual act always has the potential to lead to
pregnancy will make major demands on the body and
252. Answer given questions on the basis of your
the mind of the woman and if she is not ready for it,
understanding of the following paragraph and the
her health will be adversely affected. Therefore, many
related studies concepts.
ways have been devised to avoid pregnancy.
Carpel is present at the centre of a flower and is the
female reproductive part. It is made of three parts.
Page 166 How do organisms Reproduce Chap 8

The swollen bottom part is the ovary, the middle stamens and carpels. Stamen is the male reproductive
elongated part is the style and the terminal part part and it produces pollen grains that are yellowish
which may be sticky is the stigma. The ovary contains in colour. Carpel is present in the centre of a flower
ovules and each ovule ha an egg cell. The male germ- and is the female reproductive part. It is made of
cell produced by pollen grain fuses with the female three parts. The swollen bottom part is the ovary,
gamete present in the ovule. This fusion of the germ- middle elongated part is the style and the terminal
cells or fertilization gives us the zygote which is part which may be sticky is the stigma. The ovary
capable of growing into a new plant. Thus, the pollen contains ovules and each ovule has an egg cell. The
needs to be transferred from the stamen to stigma. If male germ-cell produced by pollen grain fuses with
this transfer of pollen occurs in the same flower, it is the female gamete present in the ovule. This fusion
referred to as self-pollination. On the other hand, if of the germ-cells or fertilization gives us the zygote
the pollen is transferred from one flower to another, it which is capable of growing into a new plant.
is known as cross-pollination. This transfer of pollen
from one flower to another is achieved by agents like
wind, water or animals. After the pollen lands on a
suitable stigma, it has to reach the female germ-cells
which are in the ovary. For this, a tube grows out of
the pollen grain and travels through the style to reach
the ovary.

(i) What are the different parts of a flower?

(ii) Name the reproductive parts of a flower.
(iii) Which is the male reproductive part of a flower?
(iv) Which is the female reproductive part of a flower?
Sol :

254. Answer given questions on the basis of your

understanding of the following paragraph and the
related studies concepts.
Reproduction (or procreation or breeding) is the
biological process by which new individual organisms-
“offspring” are produced from their “parents”.
(i) What is present at the centre of the flower? Reproduction is a fundamental feature of all known
(ii) How many parts does the carpel have? life; each individual organism exists as the result of
(iii) What do you mean by cross-pollination? reproduction. There are two forms of reprodution:
(iv) What do you mean by self-pollination? asexual and sexual. In asexual reproduction, an
Sol : organism can reproduce without the involvement of
another organism. Asexual reproduction is not limited
253. Answer given questions on the basis of your to single-celled organisms. The cloning of an organism
understanding of the following paragraph and the is a form of asexual reproduction. By asexual
related studies concepts. reproduction, an organism creates a genetically similar
or identical copy of itself. The evolution of sexual
The reproductive parts of angiosperms are located in
reproduction is a major puzzle for biologists. Sexual
the flower. The different parts of a flower are sepals,
reproduction typically requires the sexual interaction
petals, stamens and carpels. Stamens and carpels are
of two specialized organisms, called gametes, which
the reproductive parts of a flower which contain the
contain half the number of chromosomes of normal
germ-cells. The flower may be unisexual (papaya,
cells and are created by meiosis, with a male typically
watermelon) when it contains either stamens or carpels
fertilizing a female of the same species to create a
or bisexual (hibiscus, mustard) when it contains both
fertilized zygote. This produces offspring organisms
Page 167 How do organisms Reproduce Chap 8

whose genetic characteristics are derived from those Name of Receptors Stimulus Location in our
of the two parental organisms. Asexual reproduction body
is a process by which organisms create genetically
similar or identical copies of themselves without Photoreceptors Light Eyes
the contribution of genetic material from another Phonoreceptors Sound Inner eyes
organism. Bacteria divide asexually via binary fission. Olfacatory receptors Smell Nose
Sexual reproduction is a biological process that creates
a new organism by combining the genetic material of Gustory receptors Taste Tongue
two organisms in a process that starts with meiosis, a Thermoreceptors Heat/Cold Skin
specialized type of cell division.
Tangoreceptors Touch Skin
Receptors are either neuron endings or specialized
cells that are in close contact with neuron endings to
perceive information about their external or internal
environments. The receptor cells receive stimuli from
the environment and transform these excitations into
electro-chemical impulse. Therefore, all the receptors
in various sense organs receive stimuli from the
surrounding environment and send messages to the
spinal cord and brain through sensory nerves. Another
type of nerve cells called motor nerves transmit the
response from the sensory organs to central nervous
system towards effectors, in the form of electrical
impulse.
(i) What is nerve impulse?
(ii) What will be the path followed by a nerve impulse
on hearing a sound?
(iii) Upon receiving a signal the dendrite tip of a nerve
cell sets off a chemical reaction that
(a) creates an electrical impulse in the dendrite.
(b) creates an electrical impulse in the next
neuron.
(c) releases some chemicals in the cell body of the
neuron.
(d) creates a stimulus.
(i) What do you mean by reproduction?
(ii) How many forms of reproduction are there? What (iv) When stimulated by a stimuli, the nerve impulses
are they? are
(iii) What do you mean by asexual reproduction? (a) continuously discharged.
(iv) What do you mean by sexual reproduction? (b) discharged for a short time.
Sol :
(c) discharged at different rates depending on the
type of receptor.
255. Answer given questions on the basis of your (d) discharged it a high rate initially and declines
understanding of the following paragraph and the later.
related studies concepts. Sol :
A receptor is a specialised cell or a group of cells
in a sense organ that perceive a particular type of
256. Answer given questions on the basis of your
stimulus in the environment like light, heat, pressure,
understanding of the following paragraph and the
etc. Different sense organs have different receptors for
related studies concepts.
detecting different stimuli.
To carry out a simple function such as eating food
there has to be coordination of the eyes, hands and
Page 168 How do organisms Reproduce Chap 8

the mouth. The eyes have to focus on the food, the (c) Bark (d) Pith
hands have to pick it up and take it to the mouth (ii) The cells placed in the nutrient medium for tissue
where it will be chewed. All these actions have to culture grow rapidly to form.
be coordinated in such a manner that they follow
(a) Thallus (b) Callus
a particular sequence and the action is completed.
A similar mechanism is also needed for internal (c) Hyphae (d) Protonema
functions of the body. This function is carried out by (iii) Give two advantages of tissue culture.
the nervous system. (iv) What is meant by vegetative propagation?
It is composed of : Sol :
(a) specialised cells which can detect, receive and
transmit different kinds of stimuli. These are 258. Answer given questions on the basis of your
called neurons. understanding of the following paragraph and the
(b) nerve fibres which are certain bundles of extended related studies concepts.
processes of nerve cells. To make a bread dough, a baker mixes flour, sugar and
baking powder (mixture of baking soda and tartaric
acid). After mixing all the ingredients, the dough is
placed in a container for a few hours (in an oven).
On heating, the mixture releases carbon dioxide gas
leaving bubbles behind. This increases the size of the
bread and makes it soft and spongy. Tartaric acid
helps in removing bitter taste.

The individuals also have to adjust to the changing

conditions of the body should vary their responses.
At the same time, the internal conditions of the
body should be maintained constant. This is called
homeostasis. The internal conditions of the body are
maintained at a constant by controlling the physiology
of the organisms.
(i) What will the correct sequence in which conduction
of information through nerves take place?
(ii) How homeostasis is said to maintain the
equilibrium of the body?
(iii) What function does the central nervous system
perform? (i) Why does the bread dough rise?
(iii) What happens when the dendrite tip of a nerve (ii) ‘Yeast can be used in place of baking powder for
cell receives a signal? making bread dough’. What is yeast?
Sol : (iii) What would you use to measure pH of baking
powder?
257. Answer given questions on the basis of your (iv) Based on the graph represented alongside, answer
understanding of the following paragraph and the the following questions:
related studies concepts. A bakery shop started using baking soda instead
In tissue culture, the call us is transferred to a medium of baking powder for baking cakes. What could be
that contains hormones for growth and differentiation. the reason for the decrease in the sale of cakes?
Sol :
(i) From which part of the plant are the cells
extracted for tissue culture?
For solutions download NODIA app.
(a) Growing tip (b) Leaves
Page 169 How do organisms Reproduce Chap 8

259. Answer given questions on the basis of your

understanding of the following paragraph and the
related studies concepts.
The female germ-cells or eggs are made in the ovaries.
They are also responsible for the production of some
hormones. When a girl is born, the ovaries already
contain thousands of immature eggs. On reaching
puberty, some of these start maturing. One egg is
produced every month by one of the ovaries. The
egg is carried from the ovary to the womb through
a thin oviduct or fallopian tube. The two oviducts
unite into an elastic bags-like structure known as the
uterus. The uterus opens into the vagina through the
cervix. The sperms enter through the vaginal passage
during sexual intercourse. They travel upwards and
reach oviduct where they may encounter the egg. The
fertilized egg, the zygote, gets implanted in the lining
of the uterus and starts dividing. We have seen in (i) Where are the female germ-cells made?
earlier sections that the mother’s body is designed (ii) What happens to the eggs when females reach
to undertake the development of the child. Hence, puberty?
the uterus prepares itself every month to receive and (iii) What is the role of fallopian tube?
nurture the growing embryo. The lining thickness and (iv) What do you mean by uterus?
is richly supplied with blood to nourish the growing Sol :
embryo.
260. Answer given questions on the basis of your
understanding of the following paragraph and the
related studies concepts.
Gregor Mendel, conducted the hybridisation
experiments by applying statistical analysis and
mathematical logic. The confirmation of his inferences
from experiments on successive generations of his test
plants, proved that his results pointed to general
rules of inheritance. Mendel investigated characters
in garden pea plant that were manifested as two
opposing traits e.g. tall and dwarf plants, yellow and
green seeds, etc. He conducted his cross-pollination
experiments using several true breeding pea lines,
i.e. the ones that have undergone condinuous self-
pollination and shows stable trait inheritance and
expression for several generations.
(i) What determines the trait of an organism?
(ii) What is a true breeding line?
(iii) Based on the figure below, workout which trait
should be considered dominant and which one is
recessive?
Page 170 How do organisms Reproduce Chap 8

Uttar Pradesh 880 870

Punjab 895 880
Name the state which improves the ratio to
maximum extent in 2013-15.
(a) Punjab (b) Delhi
(c) Haryana (d) Uttar Pradesh
(ii) According to the table in above question, which
state declines this ratio to maximum extent in
2013-15.
(a) Haryana (b) Uttar Pradesh
(c) Punjab (d) Delhi
(iii) What is the major cause of less females than
males in India?
(a) Males live longer than females
(b) Female foeticide
(c) Naturally, male child birth rate is higher than
female child
(d) None of these
(iv) Which of the following is not a common sign of
sexual maturation in boys and girls.
(a) Wider chest in males
(iv) If a round and yellow seeded plant is crossed (b) Broad shoulders in females
with a plant with wrinkled and green seeds, what
(c) Menstrual cycle in females
would be the phenotypic ratio of the F2 progeny?
Sol : (d) Pubic hair
(v) Which contraceptive method changes the
261. Answer given questions on the basis of your hormonal balance of the body?
understanding of the following paragraph and the (a) IUCD (b) Condoms
related studies concepts.
(c) Orals pills (d) None of these
The growing size of the human population is a cause of Sol :
concern for all people. The rate of birth and death in a
given population will determine its size. Reproduction
is the process by which organisms increase their 262. Answer given questions on the basis of your
population. The process of sexual maturation for understanding of the following paragraph and the
reproduction is gradual and takes place while general related studies concepts.
body growth is still going on. Some degree of sexual The transfer of pollen grains from anther to stigma of
maturation does not necessarily mean that the mind a flower is called pollination.
or body is ready for sexual acts or for having and This act is very important because, it is the need for
bringing up children. Various contraceptive devices fertilisation and seed formation.
are being used by human beings to control the size of When the anther produces pollen grains and it is
population. transferred to stigma of the same flower, it is called
(i) Sex ratio of females per thousand males in self-pollination. For which the maturation of both,
different states are as follows: anther and pistil at the same time is essential.
When the anther produces pollen grains and it is
States 2013-15 2012-14 transferred to stigma of another flower, it is called
Delhi 870 880 cross-pollination. Various agents help in the transfer
Haryana 840 870 of pollen grains. These agents are called pollinating
agents, such as insects, wind, water, animals, birds,
Page 171 How do organisms Reproduce Chap 8

etc. (iii) Which of the following agents may help in the

This transfer of pollen from one flower to another is transfer of pollen grains from one flower to
achieved by agents like wind, water or animals. another flower?
After the pollen lands on a suitable stigma, it has to (a) Animals (b) Air
reach the female germ-cells which are in the ovary. For (c) Water (d) All of the above
this, a tube grows out of the pollen grain and travels
(iv) The fusion of male and female gametes is called:
through the style to reach the ovary.
(a) Germination (b) Pollination
After fertilisation, the zygote divides several times to
form an embryo within the ovule. The ovule develops (c) Fertilisation (d) None of the above
a tough coat and is gradually converted into a seed. (v) The transfer of pollen grains from another lobes
The ovary grows rapidly and ripens to form a fruit. of one flower to the stigma of anther flower is
Meanwhile, the petals, sepals, stamens, style and called:
stigma may shrivel and fall off. The seed contains the (a) Cross-pollination (b) Fertilisation
future plant or embryo which develops into a seedling
(c) Self-pollination (d) None of these
under appropriate conditions. This process is known Sol :
as germination.

263. Answer given questions on the basis of your

understanding of the following paragraph and the
related studies concepts.
If the zygote is to grow and develop into an organism
which has highly specialised tissues and organs, then
it has to have sufficient stores of energy for doing
this. In very simple organisms, it is seen that the two
germ-cells are not very different from one another,
or may even be similar. But as the body designs
become more complex, the germ-cells also specialise.
One germ-cell is large and contains the food-stores
while the other is smaller and likely to be motile.
Conventionally, the motile germ-cell is called the male
gamete and the germ-cell containing the stored food is
called the female gamete. These two different types of
gametes give rise to differences in the male and female
reproductive organs and, in some cases, differences in
the bodies of the male and female organisms.
(i) What is formed due to fusion of male and female
gamete?
(a) Organism (b) Zygote
(c) Male gamete (d) Female gamete
(ii) Which of the following structure develops into an
organism?
(a) Ovum (b) Sperm
(c) Zygote (d) All of the above
(i) The structure formed after fertilisation is:
(iii) In human beings, the male germ-cell is called:
(a) Zygote (b) Pollen grain
(a) Ovum (b) Tissue
(c) Ovule (d) Seed
(c) Zygote (d) Sperm
(ii) Which of the following structure develops into
(iv) The female germ-cell in human beings is called:
seed?
(a) Ovum (b) Zygote
(a) Ovule (b) Ovary
(c) Sperm (b) Gamete
(c) Stigma (d) Zygote
Page 172 How do organisms Reproduce Chap 8

(v) Which of the following germ-cell Gamete) is

larger, non-motile and stores food?
(a) Ovum (b) Sperm
(c) Both (a) and (b) (d) None of these
Sol :

264. Answer given questions on the basis of your

understanding of the following paragraph and the
related studies concepts.
The reproductive parts of a flowering plants are located
in the flower. The flower may contain either stamens Parts of Seed Definition Function
or carpels or both. For producing new generation,
pollen from stamens need to be transferred to carpels. (a) 1 represents Seed leaf Provides
Later on, the seed develops, which contains the future cotyledon within the nourishment
plant. embryo for the
growing plant.
(i) Which of the following statements correctly
describes the function of parts of carpel? (b) 5 represents The primary Anchoring the
(a) Stigma is the site of fertilization plumule root seedling

(b) Ovary receives the pollen (c) 3 represents The young Bearing the
radicle shoot first true
(c) Ovule contains the female germ-cell leaves of a
(d) Style gives rise to pollen tube plant
(ii) The given diagram represents the longitudinal (d) 2 represents Outer A source of
section of watermelon flower. seedcoat covering of stored food
the ovule
(iv) Which of the following statement are true about
the parts of a typical flower?
I. Middle elongated part of a carpel is termed as
filament.
II. Stamens are present at the centre of the
flower.
III. Stigma is the terminal sticky part of a carpel.
IV. The ovary contains ovules and each ovule has
an egg cell.
Such flowers are not able to self-pollinate because (a) I and II only (b) III and IV only
(a) it is a bisexual flower (c) II and IV only (d) I and III only
(b) it is unisexual flower (v) Study the table given below and select the row
that has the correct information.
(c) it contains short style
(d) it doesn’t contain sepals Type of Flower Example
(iii) Study the picture given below and choose the (a) Bisexual Papaya
correct combination of plots provided in the (b) Unisexual Hibiscus
following table.
(c) Bisexual Mustard
(d) Bisexual Maize
Sol :

265. Answer given questions on the basis of your

understanding of the following paragraph and the
Page 173 How do organisms Reproduce Chap 8

related studies concepts. generation can be created.

In our country, ultrasound imaging (echography) is (i) The term ‘clone’ cannot be applied to offspring
used to take images of the developing babies (foetus). formed by sexual reproduction because
It is considered safe for both the mother and the (a) offspring do not possess exact copies of
foetus. In this method, the doctor holds a probe and parental DNA
moves it across the abdomen of the mother.
(b) DNA of only one parent is copied and passed
Ultrasound waves which are transmitted into the on to the offspring
abdomen are reflected from the surface of the foetus.
These reflected waves are picked up by the probe (c) offspring are formed at different times
and relayed to a machine that produces the image (d) DNA of parent and offspring are completely
of the developing baby. In some parts of our country, different
ultrasound is done illegally. (ii) Given graph represents two populations,
(i) What could be the reason of performing ultrasound reproducing sexually and asexually.
illegally?
(ii) “Man, and not the woman is responsible for the
birth of a girl child.” What is meant by this
statement?
(iii) Can ultrasound examination of expecting mothers
answer the following questions? Write ‘Yes’ or
‘No’.
(a) What is the colour of the baby’s eyes?
(b) Is there more than one foetus?
(iv) Based on the data shown in the graph alongside,
state what could be the reason for the decline in
the boys child sex ratio ?

According to the graph, Animal A population

survived because of
(a) variations within the population
(b) larger number of viable offspring
(c) a greater number of female individuals
(d) different forms for each generation
(iii) Honeybees produce their young ones only by
sexual reproduction.
Insite of this, in a colony of bees we find both
haploid and diploid individuals.
Choose the correct combination of plots provided
Sol : in the following table.

266. Answer given questions on the basis of your

understanding of the following paragraph and the
related studies concepts.
Bulls alone cannot produce new calves, nor can
hens alone produce new chicks. In such cases, both
sexes, males and females are needed to produce new
generations. So, such modes of reproduction depend
on the involvement of two individuals before a new
Page 174 How do organisms Reproduce Chap 8

Queen Worker Drone (b) sperm formation requires a higher temperature

than the normal body temperature
(a) Fertile diploid Sterile Fertile
female diploid haploid (c) testosterone secretion requires a higher
females males temperature than the normal body
temperature
(b) Sterile diploid Fertile Fertile
females haploid diploid (d) testosterone secretion requires a lower
males female temperature than the normal body
temperature
(c) Fertile diploid Fertile Sterile
female haploid diploid (ii) The given graph shows the hormonal changes
males females during a normal menstrual cycle.
(d) Fertile haploid Sterile Fertile
males diploid diploid
females female
(iv) Which of the following statement(s) is (are) true
about sexual reproduction?
I. It ensures the creation of new variants.
II. Somatic cells are involved.
III. It ensures the genetic recombination.
IV. The rate of reproduction is faster.
(a) I and II only (b) I and III only
(c) II and III only (d) I and IV only
(v) Study the table below and select the row that has What would be a likely consequence if the
the incorrect information. hormone represented by graph Q is lacking in an
Type of gamete Conventional features adult female?
(a) The uterine lining might not be sufficiently
(a) Female Large and non-motile stable for implantation of fertilised ovum.
(b) Male Small and motile (b) Levels of the hormone represented by graph
(c) Female Large, motile and stores P would be higher than normal.
food (c) Fertilisation of ovum would fail to occur.
(d) Female Large and stores food (d) There would be no significant effect since the
Sol : functions of the hormones overlap.
(iii) Given below is the outline of the male reproductive
267. Answer given questions on the basis of your system.
understanding of the following paragraph and the
related studies concepts.
Humans use sexual mode of reproduction. But the
actual transfer of germ cells between two people
needs special organs for the sexual act. In mammals
such as humans, the baby is carried in the mother’s
body for a long period, and is breastfed later. The
female reproductive organs and breasts will need to
mature to accommodate these possibilities. Hence
some specialized systems are involved in the process
of sexual reproduction.
(i) In humans, testes are located outside the Identify A, B , C and D to choose the correct
abdominal cavity in scrotum because combination of plots provided in the following
(a) sperm formation requires a lower temperature table.
than the normal body temperature
Page 175 How do organisms Reproduce Chap 8

A B C 268. Answer given questions on the basis of your

understanding of the following paragraph and the
(a) Forms germ Stores Helps sperms related studies concepts.
cells sperm for to move
The sexual act is a very intimate connection of bodies
maturation towards the
so that may lead to transmission of many diseases. Is
female germ
it possible to prevent the transmission of such disease?
cell
The sexual act always has the potential to lead to
(b) Secretes Transports Produce pregnancy. Is there any way to avoid pregnancy? It is
primary male mature seminal fluid possible via surgery but this method may be misused
sex hormone sperm to ‘D ’ by people who do not want a particular child. As
(c) Located outside Produce Stores reproduction leads to increase in population size, the
the abdominal seminal fluid sperm for size of the human population is a cause of concern for
cavity maturation many people.
(d) Requires a lower Helps sperms Transports (i) Vasectomy is
temperature to move mature (a) also called tubectomy
than the towards the sperm to ‘D ’ (b) a method of preventing the passage of eggs
normal body female germ
temperature cell (c) a method of blocking the continuity of oviduct
(d) a method of sterilization in human males
(iv) Which of the following statement(s) is (are) true
about reproduction in human beings? (ii) The given graph indicates the percentage of
I. As the rate of general body growth begins widely used postpartum contraceptive methods
to slow down, reproductive tissues begin to among women of a country.
mature.
II. When a girl is born, the ovaries already
contain thousands of mature eggs.
III. The embryo gets nutrition from mother with
the help of placenta.
IV. The egg is carried from the ovary to the womb
through ureter.
(a) I and III only (b) II and III only
(c) II and IV only (d) III and IV only
(v) Study the table below and select the row that has
the incorrect information.

Menarche Menopause
(a) Starting of End of menstruation
menstruation in human in human females
females
(b) Occurs at around 11-16 Occurs at around
years of age 40-45 years of age
(c) Marks the end of Marks the start of
reproductive phase reproductive phase Out of the given methods, number of natural
(d) Repeated process Non-repeated family planning methods is
process (a) 7 (b) 3
Sol : (c) 8 (d) 1
(iii) The given box consists of various diseases.
For solutions download NODIA app.
Identify the sexually transmitted diseases and
choose the correct combination of plots provided
in the following table.
Page 176 How do organisms Reproduce Chap 8

Measles AIDS Tetanus Syphilis (ii) Name one characteristic body feature of organism
A.
Gonorrhoea Scabies Mumps Cholera
(iii) Name the insect which carries organism B and
Typhoid Filaria transmits it from one person to another.
(iv)What name is given to the asexual method of
STD-1 STD-2 STD-3 reproduction of (i) organism A, and (ii) organism
B?
(a) AIDS Scabies Filaria
(v) Where do organisms C and D live?
(b) Syphilis Gonorrhoea Mumps Sol :
(c) Gonorrhoea AIDS Syphilis
270. Answer given questions on the basis of your
(d) Cholera Tetanus ‘Typhoid
understanding of the following paragraph and the
(iv) Which of the following statement(s) is (are) true related studies concepts.
about reproductive health of humans? Two very small organisms X and Y both reproduce
I. Condoms serve the role of mechanical barrier by the method of budding. Organism X is industrially
in pregnancies. very important because it is used in making alcohol
II. The copper-T are placed in the uterus to from sugar. It is also used in making alcohol from
prevent ovulation. sugar. It is also used in making bread. Organism
III. If the fallopian tube in the female is blocked, Y lives in freshwater. If organism Y gets cut into a
the egg will not be able to reach the uterus. number of parts accidentally, each cut part can grow
to form complete organism.
IV. Surgery can’t be used for removal of unwanted
pregnancies. (i) What are organisms X and Y ?
(a) I and II only (b) II and III only (ii) What is the name of the process in which X
converts sugar into alcohol?
(c) I and III only (d) I, III and IV only
(iii) To which class of organisms does X belong?
(v) Study the table below and select the row that has (iv) Name an important body feature of organism Y .
the incorrect information.
(v) Which organism is multicellular and which one is
Method Mode of action unicellular?
Sol :
(a) Pill Prevents ovulation
(b) Tubectomy Prevents the egg from reaching 271. Answer given questions on the basis of your
the uterus understanding of the following paragraph and the
(c) Condom Prevents eggs reaching cervix related studies concepts.
When a moist slice of bread was kept aside for a
(d) IUDs Disrupts the process of
conception few days then some organism grew on it to form a
Sol : white cottony mass which later turned black. When
this slice of bread was observed through a magnifying
glass, then fine thread-like projections and thin stems
269. Answer given questions on the basis of your having bulb-like structures at the top were seen.
understanding of the following paragraph and the (i) What is the common name and scientific name
related studies concepts. of the organism which grew on the moist slice of
There are four tiny organisms A B , C and D . The bread?
organism A is a parasitic protozoan which causes (ii) How did this organism grow on the moist slice of
a disease known as kala-azar. The organism B is a bread automatically?
microscopic single-celled animal which causes malaria
(iii) What are the fine, thread-like projections on the
disease in human beings. The organism C is a
surface of slice of bread known as?
unicellular animal which can change its body shape
according to need, it has no fixed shape. The organism (iv) What name is given to the knob-like structures
D is also a unicellular animal which is slipper-shaped and what do they contain?
having a large number of tiny hair all around its body. (v) What is the name of this method of reproduction?
(i) Name the organisms A, B , C and D (vi) Name one unicellular organism which reproduces
by this method.
Page 177 How do organisms Reproduce Chap 8

(vii)Name two non-flowering plants which reproduce (iii) What name is given to the cut stem of tree Y
by this method. which has no roots but has some leaves?
Sol :
(vi) Name the layer Z .
(v) Why should the layer Z of one cut stem be in
272. Answer given questions on the basis of your contact with the layer Z of the other cut stem?
understanding of the following paragraph and the (vi) Name any four fruit trees which are usually bred
related studies concepts. by this technique.
A scientist removed some cells from the growing point (vii)State any one advantage of producing fruit trees
of a plant and placed it in a suitable medium leading by this technique.
to the formation of a shapeless lump of mass X . X is Sol :
then transferred to another medium which stimulates
it to develop roots. When X with developed roots is
274. Answer given questions on the basis of your
placed in a yet another medium, then it developed
understanding of the following paragraph and the
shoots to form tiny plantlets. These plantlets can then
related studies concepts.
be transplanted in pots or soil where they can grow to
A small part of shoot of a plant is removed with a
form mature plants.
sharp knife. When the lower end of this small part of
(i) What is the shapeless lump of mass X known as?
the shoot is buried in moist soil, it gradually develops
(ii) What name is given to this method of producing roots and shoots and grows to become a new plant.
new plants?
(i) What is the name of this method of propagating
(iii) The growth medium used in this method contains plants?
plant nutrients in the form of a ‘jelly’ Name this
(ii) What care should be taken while removing a
jelly.
small part of the shoot from the parent plant with
(iv) What is the general name of chemicals used a knife?
to stimulate the growth of plant cells and
(iii) Name any two plants which provide us with
development of roots and shoots?
food directly or indirectly and are grown by this
(v) Name any two plants which are produced by this method.
method.
(iv) Give one advantage of this method of producing
(vi) What is the other name of this method [other new plants.
than that given in (b) above?
Sol : (v) State whether it is a sexual method of reproduction
or an asexual method. Why?
(vi) What special name can be given to the genetically
273. Answer given questions on the basis of your
identical new plants produced by this technique?
understanding of the following paragraph and the Sol :
related studies concepts.
The stem of a fruit tree X fixed in soil is cut in a
275. Answer given questions on the basis of your
slanting way. The upper part of stem of another fruit
understanding of the following paragraph and the
tree Y of different variety of same species is also cut in
related studies concepts.
a slanting way. The cut stem of tree Y , without roots
When the branches of a plant growing in the field
but having some leaves, is placed over the rooted cut
are pulled towards the ground and a part of them
stem of tree X in such a way that their cut surfaces
is covered with moist soil (leaving the tips of the
fit together properly. While joining the two cut stems,
branches exposed above the ground), then after some
care is taken to make sure that the layer Z of one cut
time new roots develop from the parts of branches
stem is in contact with layer Z of the other cut stem.
buried in the soil. On cutting these branches from the
The joint of cut stem is bound tightly with a piece
parent plant,new plants are produced from the cut
of cloth and covered properly with polythene. Soon
parts of branches which had developed roots.
the cut heals and the two stems grow together and
become one fruit tree producing leaves, flower and (i) What is this method of propagation of plants
fruits. known as?
(i) What is the name of this method of producing (ii) What type of branches should a plant have to be
plants or trees? able to be propagated by this method?
(ii) What name is given to the cut stem of tree X (iii) Name any two plants which are grown for their
having roots? flowers and propagated by this method.
Page 178 How do organisms Reproduce Chap 8

(iv) Name any two plants which are grown for their 278. Answer given questions on the basis of your
fruits and propagated by this method understanding of the following paragraph and the
(v) Name one plant which gets propagated by this related studies concepts.
method naturally by forming runners (soft A filamentous alga X is found in ponds, lakes and
horizontal stems running above the ground). slow-moving streams. The filament of this alga simply
Sol : breaks into two (or more) pieces on maturing and
each piece then grows to become a complete new alga.
276. Answer given questions on the basis of your (i) Name an alga which X is likely to be.
understanding of the following paragraph and the (ii) What is the colour of X ?
related studies concepts. (iii) What is the method of forming new algae by the
A worm X found in freshwater and slow-moving breaking of parent alga known as?
streams has been accidentally cut into three pieces. (iv) An Amoeba also breaks up to form two daughter
It was observed that in due course of time, each cut Amoebae. What is the difference in the splitting
piece of the worm develops to become a complete of Amoeba and splitting of this alga as a method
worm by growing all the missing parts. of reproduction?
(i) Name the worm X which can exhibit this (v) Name one marine animal which reproduces in the
phenomenon of making complete worm from its same way as alga X .
cut body parts. Sol :
(ii) Name another organism Y which possesses the
same characteristic of growing fully from its cut 279. Answer given questions on the basis of your
body parts. understanding of the following paragraph and the
(iii) What is the name of this process in which a related studies concepts.
complete organism is formed from its cut body When a broken piece of the stem of a plant X is
part. planted in the soil, a new plant grows from it in a
(iv) State whether X and Y are unicellular and/or week’s time. The leaves of plant X also have many
multicellular organisms. small entities Y in their margins which can fall to the
(v) Can a dog be produced completely from its cut ground alone or along with leaves and grow into new
body part (say, a cut tail) just like organisms X plants.
and Y ? Why? (i) Name a plant which X could be.
Sol :
(ii) What are the entities Y present on the leaves of
X known as?
277. Answer given questions on the basis of your (iii) Name a plant other than X which can be
understanding of the following paragraph and the reproduced from its leaves.
related studies concepts.
(iv) Name a common plant grown in many homes
A thickened underground stem X of a plant which is which can be propagated from its broken stems
swollen with stored food has a number of points Y on like plant
its surface. When the old stem X is planted in the soil
of a field in the next growing season, then each point For solutions download NODIA app.
Y present on its surface grows into a new plant. Sol :
(i) What is the general name of the underground
stems like X ?
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(ii) Give one example of X .
(iii) What are points Y present on X known as?
(iv) Is it necessary to plant the whole of stem X in the
ground the obtain its new plants? Explain your
answer.
(v) What is the name of this method of reproduction
of plants?
(vi) What is the advantage of growing new plants
from the underground stems like X ?
Sol :