Question Set C

cbse 12th Standard Biology Human Reproduction Important Questions And Answers Study Material - QB365

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Questions:

Generic 2

9 x 2 = 18

What is meant by monosporic development of female gametophyte?

How many eggs do you think were released by the ovary of a female dog which gave birth to 6 puppies?

What is parturition? Which hormones are involved in induction of parturition?

What is apomixis and what is its importance?

Define spermiogenesis and spermiation

What is fruit production without fertilisation called?

How many embryo sacs are formed in an ovule?

Why do you think that the zygote is dormant for sometime in a fertilised ovule?

Name the parts of an angiosperm flower in which development of male and female gametophyte takes place.

Generic 3

2 x 3 = 6

10.

What are the major functions of male accessory ducts and glands?

11.

Name the hormones involved in the regulation of spermatogenesis.

Generic 5

5 x 5 = 25

12.

Differentiate between:
(i) Hypocotyl and epicotyl.
(ii) coleoptile and coleorhiza.
(iii) integument and testa.
(iv) perisperm and pericarp

13.

(a) Humans reproduce ____________.(asexually / sexually)
(b) Humans are ____________.(oviparous, viviparous, ovoviviparous)
(c) Fertilisation is ____________.in humans. (external/internal)
(d) Male and female gametes are ____________. (diploid/haploid)
(e) Zygote is ____________. (diploid/haploid)
(f) The process of release of ovum from mature follicle is called ____________.
(g) Ovulation is induced by a hormone called ____________.
(h) The fusion of male and female gametes is called ____________.
(i) Fertilisation takes place in ____________.
(j) Zygote divides to form ____________. which is implanted in uterus.
(k) The structure which provides vascular connection between foetus and uterus is called ____________.

14.

Identify True/False statements. Correct each false statement to make it true:
(a) Androgens are produced by Sertoli cells. (True/False)
(b) Spermatozoa get nutrition from Sertoli cells. (True/False)
(c) Leydig cells are found in ovary. (True/False)
(d) Leydig cells synthesise androgens. (True/False)
(e) Oogenesis takes place in corpus luteum. (True/False)
(f) Menstrual cycle ceases during pregnancy. (True/False)
(g) Presence or absence of hymen is not a reliable indicator of virginity or sexual experience. (True/False)

15.

With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.

16.

Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events.

Multiple Choice Question

7 x 1 = 7

17.

Embryo sac is to ovule __________ is to an anther

(a)

Stamen

(b)

Filament

(c)

Pollen grain

(d)

Androecium

18.

In a mature embryo sac the central cell is

(a)

Single nucleate

(b)

Binucleate

(c)

Four nucleate

(d)

Eight nucleate

19.

Select the correct order of endosperm types

(a)

cellular, helobial, free nuclear

(b)

cellular, free nuclear, helobial

(c)

helobial, free nuclear, cellular

(d)

free nuclear, cellular, helobial

(e)

free nuclear, helobial, cellular

20.

A type angiosperm embryo sac at maturity is

(a)

4 nucleate - 2 celled

(b)

8 nucleate - 7 celled

(c)

4 nucleate - 4 celled

(d)

8 nucleate - 4 celled

(e)

2 nucleate - 1 celled

21.

Which type of association is found in between entomophilous flower and pollinating agent?

(a)

Mutualism

(b)

Commensalism

(c)

Cooperation

(d)

Coevolution

22.

Intraspecific incompatibility can be overcome by

(a)

Wetting of anthers

(b)

Mixed pollination

(c)

Intraovarian fertilization

(d)

Intraspecific competition

23.

Egg apparatus consists of

(a)

egg

(b)

egg and polar nuclei

(c)

Egg and synergids

(d)

Egg and antipodal cells

Case Study Questions

5 x 4 = 20

24.

The reproductive cycle in female primates is called the menstrual cycle. One ovum is released during the middle of each menstrual cycle. The cyclestarts with the menstrual phase when menstrual flow
Occurs and it lasts for 3 - 5 days. The menstrual flow results due to the breakdown of the endometrial lining of the uterus and its blood vessels which form a liquid that comes out through the vagina. The
menstrual phase is followed by the follicular phase, the primary follicles in the ovary grow to become a fully mature Graafian follicle. Both LH and FSH attain a peak level in the middle of the cycle.The
ovulatory phase is followed by the luteal phase during which the remaining parts of the Graafian follicle transform. During pregnancy, all events of the menstrual cycle stop and there is no menstruation.
1 What do you understand by the term puberty?
2.What is ovulation? When does it occùr and what induce it?
3. Write two differences between secondary follicles and Gratian' follicle

25.

During copulation (coitus) semen is released by the penis into the vagina (insemination). Themotile sperms swim rapidly, pass through the cervix, enter into the uterus and finally reach theampullary region of the fallopian tube (Figure 3.11b). The ovum released by the ovary is alsotransported to the ampullary region where fertilisation takes place. Fertilisation can only occur ifthe ovum and sperms are transported simultaneously to the ampullary region. This is the reasonwhy not all copulations lead to fertilisation and pregnancy. The process of fusion of a sperm withan ovum is called fertilisation.
I.Releasing of semen into vagina during coitus is.……
a) Spermiation
b) Spermiogenesis
c) Insemination
d) Both 1 & 2
II.Secondary oocyte completes the 2nd meiotic division with the
a)Entry of sperm into ovum
b)Entry of sperm into uterus
c)Entry of sperm into fallopian tube
d)Entry of sperm into ampulla
III.Read the following
i.The sperms move to ampullary-isthmic junction for fertilization
ii.Fertilization occurs in uterus
iii.The process of fusion of a sperm with an ovum is called fertilization
iv.Ovum is enveloped by zona pellucida
The correct combination….
a) All
b) Only i & ii
c) Only i, iii & iv
d) Only i & iv
IV.Assertion (A) : Fertilization can only occur if the ovum & sperms are transported to ampullary-Isthmic junction.
Reason (R) : Fertilization occurs in ampulla.
a) A and R are true and R is the correct explanation of A
b) A and R are true and R is not the correct explanation of A
c) A is true , R is false
d) A is false , R is true
V.Match the following
List – A List - B
A) Fertilization I) Inner mass of cells
B) Blastocyst II) 8-16 blastomeres
C) Morula III) Isthmus-Ampullary junction
D) Inner group of cells IV) Implantation
E) Outer cells V) Trophoblasts
A B C D E
a) IIII VI I I V
b) III II I IV V
c) I II III IV V
d) II IV III V I

26.

The process of formation of a mature female gamete is called oogenesis. Oogenesis is initiatedduring the embryonic development stage when a couple of million gamete mother cells (oogonia)are formed within each fetal ovary; no more oogonia are formed and added after birth. Thesecells start division and enter into prophase-I of the meiotic division and get temporarily arrested atthat stage, called primary oocytes. Each primary oocyte then gets surrounded by a layer ofgranulosa cells and is called the primary follicle. A large number of these follicles degenerateduring the phase from birth to puberty. Therefore, at puberty only 60,000-80,000 primary folliclesare left in each ovary. The primary follicles get surrounded by more layers of granulosa cells and anew theca and are called secondary follicles.
I.Find out the correct statement …..
a)Primary follicle is with oogonia
b)Primary follicle is with primary oocyte
c)Secondary follicle is with secondary oocyte
d)Tertiary follicle is with primary oocyte without antrum
II.Read the following
i.Primary follicles are surrounded by many layers of granulosa cells & theca
ii.Secondary follicles are surrounded by theca
iii.Antrum is formed at Tertiary follicle stage
The correct combinations…..
a) Only i
b) Only ii
c) Only iii
d) i, ii & iii only
III.Assertion (A) : Primary oocyte completes its first meiotic division in tertiary follicle
Reason (R) :Antrum develops during secondary follicular stage
a) A and R are true and R is the correct explanation of A
b) A and R are true and R is not the correct explanation of A
c) A is true , R is false
d) A is false , R is true
IV. Read the following & arrange them in a sequence ….
a) Ova b) Oogonia c) Primary oocyte d) Secondary oocyte e) Graffian follicle
a)a-c-b-d-e
b)c-d-e-a-b
c)b-d-c-e-a
d)b-c-d-e-a
V.Match the following
List – A List - B
A) In foetal ovary i) After Ist meiotic division
B) At puberty ii) Couple of million gametes
C) Ovulation iii) Single ovum
D) Ist polar body iv) 60,000 – 80, 000 Primordial follicles
A B C D
a) ii iv iii i
b) ii iii iv i
c) iii ii iv i
d) iv i ii iii

27.

The primary sex organs – the testis in the males and the ovaries in the females–produce gametes,i.e, sperms and ovum, respectively, by the process called gametogenesis. In testis, the immaturemale germ cells (spermatogonia) produce sperms by spermatogenesis that begins at puberty. Thespermatogonia (sing. spermatogonium) present on the inside wall of seminiferous tubulesmultiply by mitotic division and increase in numbers.
I.Read the following
i)Each seminiferous tubule consists of two types of cells.
ii)Male germ cells are also called spermatogonia.
iii)Male germ cells undergo reduction division.
The correct combination
a)Only i & ii
b)Only ii & iii
c)i, ii, iii
d)Only i & iii
II.In spermatogenesis. The phase of maturation involves…
a)Growth of spermatogonia into spermatocytes
b)Formation of spermatogonia from gonocytes through mitosis
c)Formation of spermatids from primary spermatocytes through meiosis
d)Formation of oogonia from spermatocytes through meiosis
III.Which is the correct sequence in Spermatogenesis?
a)Spermatogonia - Spermatids - Secondary spermatocytes - primary spermatocytes - sperms
b)Spermatogonia - Spermatids - primary spermatocytes - Secondary spermatocytes - sperms
c)primary spermatocytes - Secondary spermatocytes - Spermatids - Spermatogonia - sperms
d)Spermatogonia - primary spermatocytes - Secondary spermatocytes - Spermatids - sperms
IV. In humans, at the end of the first meiotic division, the male germ cells differentiate into the
a)Spermatids
b)Spermatogonia
c)Primary spermatocytes
d)Secondary spermatocytes
V.Match the following
List – A List - B
A) Spermatogonia I) Sperms
B) Primary spermatocytes II) Production of sperms
C) Spermatocytes III) Meiosis
D) Spermiogenesis IV) Mitosis
A B C D
a) IV III II I
b) IV II I III
c) I II III IV
d) II III I IV

28.

(a) Identify the pituitary hormones 'X' and 'Y' shown in the graph.
(b) Mention two functions each of X and Y in human females.

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Answers Key:

Generic 2

9 x 2 = 18

An embryo sac is called monosporic because it develops from one of the four megaspores formed from the division of megaspore mother cell.

Six eggs

Partiruition refers to the process of delivery if the fully-developed foetus,i.e.,childbirth.
Relaxin and oxytocin are the hormones involved in the process.

1. Apomixis is a form of asexual reproduction that mimics sexual reproduction and seeds are formed without fertilisation.
2. Apomictic embryos are genetically identical to the female parent.
3. If hybrid seeds can be made apomictic, the desirable characters can be maintained in the progeny.
4. It is often associated with polyembrony.

(i) Spermiogenesis is the process of transformation of spermatids into flagellated spermatozoa.
(ii) Spermiation is the process of release of spermatozoa from the seminiferous tubules.

Parthenocarpy.

One

There is an adaptation in angiospermic plants to provide assured nutrition to the developing embryo. Most zygotes divide only after certain amount of endosperm is formed. Therefore, zygote remains dormant for sometime in a fertilised ovule.

1. Male gametophyte - In the Anther (microsporangia) and later on the stigma and style.
2. Female gametophyte - inside the ovule.

Generic 3

2 x 3 = 6

10.

The male accessory ducts are rete testis, vasa efferentia, epididymis and vas deferens.These ducts store and transport the sperms from the testes to the outside through the urethra. The male accessory glands are paired seminal vesicles, prostate gland and paired Bulbourethral glands. The secretion of these glands forms seminal plasma, which is rich in fructose, calcium and certain enzymes. The secretion of Bulbourethral glands lubricates the glans penis.

11.

Hormones controlling spermatogenesis.
Spermatogenesis is initiated by an increase in the secretion of GnRH (gonadotropin-releasing hormone) by the hypothalamus, at the age of puberty.
The increased levels of GnRH act on the anterior pituitary and stimulate it to secrete two gonaditropins namely:
(i) Follicle Stimulating Hormone (FSH) and
(ii) Luteinizing Hormone (LH).
LH acts o the Leydig cells and stimulates them to secrete testosterone.
FSH acts on Sertoli cells and stimulates them to secrete some factors which help in spermiogenesis.

Generic 5

5 x 5 = 25

12.

(i)

Hypocotyl	Epicotyl
Hypocotyl is the region of embryonal axis between the radicle and the point of attachment of cotyledons	Epicotyl is the region of embryonal axis between the plumule and the point of attachment of cotyledons

(ii)

Coleoptile	Coleorhiza
Coleoptile is the foliaceous sheath that covers the plumule in the embryo of cereals.	Coleorhiza is the covering of the radicle in the embryo of cereals

(iii)

Integument	Testa
It is the protective covering of the ovule. It develops into the seed coat	Testa is the outer layer of the seed coat. It develops from the outer integument.

(iv)

Perisperm	Pericarp
Peri sperm is the residual, persistent nucellus (of ovule) in the seed. It is a part of the seed and nutritive in function	Peri carp is the wall of fruit formed by the ovary wall. It is a part of the fruit and protective in function.

13.

(a) sexually
(b) viviparous
(c) internal
(d) haploid
(e) diploid
(f) ovulation
(g) luteinising hormone
(h) syngamy
(i) ampullary-isthmic junction
(j) blastula
(k) umbilical cord.

14.

(a) False
Androgens are formed by Leydig cells.
(b) True.
(c) False
Oogenesis takes place in the ovarian follicles.
(d) True
(e) False
Oogenesis occurs in the female embryo before birth but does not complete until puberty.
(f) True.
(g) True.

15.

1. The ovule is attached to the placenta by a short stalk called funiculus.
2. The junction between the funiculus and the ovule, is called hilum.
3. The primordium of the ovule grows into a mass of cells, forming the nucellus, the main body of the ovule.
4. It becomes surrounded by two protective envelopes called integuments, which leave a small opening called micropyle, at the tip of the ovule.
5. The basal part of the ovule (opposite to the micropyle) is called chalaza. Cells of the nucellus are rich in reserve food materials.
6. There is a single embryo sac/female gametophyte in the nucellus; it has developed from a megaspore.
7. The embryo sac contains the following cells:
(i) Three antipodal cells at the chalazal end.
(ii) Three cells at the micropylar end, forming egg apparatus, which consists of two synergids and a female gamete.
(iii) Two nuclei in the central cell, called polar nuclei, which fuse to form a diploid secondary nucleus.

16.

Microsporogenesis	Megasporogenesis
It occurs inside the microsporangia of anther. Many microspore mother cells are differentiated in a microsporangium. All the four cells of the microspore tetrads continue to grow.	It occurs in the nucellus of the ovule/megasporangium. Only one megaspore mother cell is differentiated in a megasporangium. Only one of the four cells in the megaspore tetrad continues to grow.

Meiosis occurs during sporogenesis.
The structure formed at the end are microspores and megaspores respectively.

Multiple Choice Question

7 x 1 = 7

17.

18.

(b)
Binucleate

19.

20.

(b)
8 nucleate - 7 celled

21.

(a)
Mutualism

22.

(b)
Mixed pollination

23.

Case Study Questions

5 x 4 = 20

24.

1.The age of attaching sexual maturity is called puberty
2.The release of secondary 00cyte from the graffian follicle is called ovulation. It occurs on 14h day of menstrual cycle. LH surge induces it.
3.Secondary follicle has no antrum and has one theca enclosing primary oocyte while graffian follicle has antrum and has two theca enclosing secondary oocyte

25.

(I) c) Insemination
(II) a) All
(III) c) Only i, iii & iv
(IV) c) A is true , R is false
(V) a) IIII VI I I V

26.

(I) b) Primary follicle is with primary oocyte
(II) d) i, ii & iii only
(III) c) A is true , R is false
(IV)d) b-c-d-e-a
(V) a) ii iv iii i

27.

I) c) i, ii, iii
II) c)Formation of spermatids from primary spermatocytes through meiosis
III d)Spermatogonia - primary spermatocytes - Secondary spermatocytes - Spermatids - sperms
IV d)Secondary spermatocytes
V) a)IV III II I

28.

(a) X is luteinizing hormone (LH).
Y is follicle-stimulating hormone (FSH).
(b) Functions of X
(i) The LH-surge causes rupture of Graafian follicle and release of ovum, in the process, called ovulation.
(ii) It influences the formation of corpus luteum from the remaining parts of the Graafian follicle and secretion of progesterone from it.
Functions of Y
(i) It stimulates the growth of a primary follicleinto a Graafian follicle and thus, influences oogenesis.
(ii) It stimulates the cells of the developing follicle to secrete estrogens.