Human Reproduction

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Questions:

1 Marks

5 x 1 = 5

Name the ducts received by urethra in a human male.

What is urethral meatus?

What is ehaculatory duct?

When do oogenesis and spermatogenesis initiate in human female and male,respectively?

Name the calls that nourish the germ cells in the testes.Where are these cells located in the testes?

Generic 2

3 x 2 = 6

Differentiate between morula and blastocyst.

Define ovulation.When does it occur?

Bring out the differences between secondary and tertiary follicles.

Generic 3

4 x 3 = 12

(a) Mention the event of meiosis that occurs in the tertiary follicle in a human ovary.
(b) Name the phase of menstrual cycle,when a Graafian follicle transforms into an endocrine structure.Write its action thereafter.

10.

Describe the different parts of the fallopian tube of human female reproductive system.

11.

Name the source of gonadotropins in human females.Explain the changes brought about in the ovary by these hormones during menstrual cycle.

12.

Mention the target cells of lutenising hormone in human males and females.Explain the effect and the changes which the hormone induces in each case.

Generic 5

3 x 5 = 15

13.

How is 'oogenesis' markedly different from spermatogenesis with respect to the growth till puberty in the humans?

14.

Purnima visited her native village with her grandmother. In the village, she saw some ladies, even pregnant, were smoking bidies. She also saw a child cleft palate in the lap of one of the returns home. On the way, she told Dadaji that she is planning to start campaign to make these illiterate women aware about ill effects of tobacco on health.
Read the above passage and answer the following questions:
(i) Is there any harmful effect of use of tobacco smoking on our health?
(ii) Explain briefly the effects of smoking on human health?
(iii) What is the effects of tobacco on next generation?

15.

(a) Draw a diagramatic sectional view of human ovary showing different stages of oogenesis along with corpus luteum.
(b) Where is morula formed in human?Explain the process of its development from zygote.

Multiple Choice Question

5 x 1 = 5

16.

Which one of the following statements is false in respect of viability of mammalian sperm?

(a)

Sperm is visible for only up to 24 hours

(b)

Survival of sperm depends on the pH of the medium and is more active in alkaline medium

(c)

Viability of sperm is determined by its motility

(d)

Sperms must be concentrated in a thick suspension.

17.

Which one of the following is the most likely root cause why menstruation is not taking place in the regularly cycling human female?

(a)

retention of well-developed corpus luteum

(b)

fertilization of the ovum

(c)

maintenance of the hypertrophical endometrial lining

(d)

maintenance of high conc. of sex hormones in the blood stream

18.

1st polar body is formed at which state of oogenesis?

(a)

1st meiosis

(b)

2nd mitosis

(c)

1st mitosis

(d)

differentiation

19.

Some important events in the human female reproductive cycle are given below.Arrange the events in a proper sequence.A-secretion of FSH, B-growth of corpus luteum, C-growth of the follicle and oogenesis, D-ovulation, E-sudden increase in the levels of LH

(a)

A D C E B

(b)

B A C D E

(c)

C A D B E

(d)

A C E D B

20.

In human beings, the eggs are:

(a)

Skin lecithal

(b)

Macrolecithal

(c)

Mesolecithal

(d)

Alecithal

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Answers Key:

1 Marks

5 x 1 = 5

()
Ducts of prostate glands and Coeper's glands.

()
Urethral meatus refers to the external opening of urethra at the tip of the penis.

()
The vas deferens after receiving the duct from seminal vesicle,is called ejaculatory duct.

()
Oogenesis starts during embryonic developmental stages of the female foetus.

Spermatogenesis starts at puberty.

()
Sertoli cells.They are found on the inner lining of seminiferous tubule .

Generic 2

3 x 2 = 6

Morula is a mulbery like solid mass of 8-16 cells called blastomeres, formed by cleavage of zygote, while the blastocyst is a hollow sphere of 64 cells formed by the rearrangement of blastomeres of morula. It has a cavity called blastocoel and an inner cell mass within. It also has an outer envelop of cells called the trophoblast.

Ovulation is the process of rupture of a mature Graafian follicle and the subsequent release of ovum from it.
It occurs around the 14th day/middle of the menatrual cycle.

Secondary follicle

Tertiary follicle

When the primary follicle containning the promary oocyte becomes surrounded by more layers of granulosa cells and a thecal layer,it is called secondary follicle.
The oocyte shows little growth.

When a fluid-filled cavity develops around the oocyte in the secondary folicl,it is called tertiary follicle.
The oocyte grows in size and undergoes meiosis I.

Generic 3

4 x 3 = 12

(a) The primary oocyte grows in size and completes meosis I,forming a larger haploid cell,the secondary oocyte and a smaller cell,the first polar body.
(b) In the luteal phase,the ruptured graafian follicle transforms into corpus luteum.
Corpus luteum secretes large quantity of progesterone to maintain the endometrium.

10.

Each fallopian tube extends from the periphery of each ovary to the uterus.
The part of the fallopian tube closer to the ovary is the funnel-shaped infundibulum.
The edges of the infundibulum possess finger like projections,called fimbriae.
The infundibulum leads to the wider part of the fallopian tube,called ampulla.
The last part of the oviduct with a narrow lumen;is called isthmus;it joins the uterus.

11.

Gondotropins are secreted by the anterior pituitary.

Follicle stimulating hormone (FSH) and luteinising hormone (LH) are the gonadotropins.

FSH stimulates follicular development and secretion of estrogens by the follicle cells.

Both FSH and LH attain a peak level around the middle of the cycle(about 14th day).

The maximum level of LH (also called LH surge) induces ovulation,i.e.,rupture of the mature follicle and release of ovum/secondary oocyte.

LH stimulates the formation of corpus luteum from the ruptured follicle and secretion of progesterone from the corpus luteum.

12.

The target cells for luteinising hormone in males are the Leydig cells and in females are the mature follicles.

LH in males stimulates the Leydig cells of testes to secrete androgens (testosterone) which controls spermatogenesis.

LH in females stimulates ovulation formation of corpus luteumfrom the reptured follicle and secretion of progesterone by corpus luteum.

Generic 5

3 x 5 = 15

13.

Difference between spermatogenesis and oogenesis are as follows

Spermatogenesis	Oogenesis
It begins and gets completed in the testis only.	It begins in the ovary and is completed in the female reproductive tract.
It is not a cyclic process, it occurs continuously.	It is a cyclic process, completed every 28/29 days
Spermatogonia change to primary spermatocytes.	Oogonia change to primary oocytes.
A primary spermatocyte divides to form two secondary spermatocytes.	A primary oocyte divides to form the secondary oocyte and one polar body.
The secondary spermatocyte divides to form two spermatids.	A secondary oocyte divides to form one ootid and one polar body.
A spermatogonium forms spermatozoa.	An oogonium forms one ovum.

14.

(i) Yes, It effects not only health of smoker but also persons around the smoker.
(ii) Smoke contains toxic gasses and tar which is not good for health and may cause cancer of oral cavity and respiratory.
(iii) Long use of tobacco product may damage the genetic material and as a result malformed infants may be formed in women who use tobacco products regularly.

15.

(b) Morula is formed in the isthmus of the oviduct/fallopian tube.
The zygote undergoes mitotic divisions in quick succession,called cleavage,forming 2,4,8 and 16 daughter cells,called blastomeres.
The embryo with 8-16 blastomeres is called a morula.

Multiple Choice Question

5 x 1 = 5

16.