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) Mentrual cycle ceases during pregnancy. (True/False)
(g) Presence or absence of hymen is not a reliable indicator of virginity or sexual experience. (True/False)

(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 ____________.

What roles does pituitary gonadotrophins play during follicular and ovulatory phases of menstrual cycle? Explain the shifts in steroidal secretions. 

The zygote passes through several development stages till implantation.Describe each stage briefly with suitable diagrams.

Describe the formation of three germ layers in a mammalian embryo.

'A fertilised egg is a blueprint for future development'.Explain.

Give the structure of simple type placenta.

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?

Describe the specific action of FSH, LH, oestrogen and progesterone in the menstrual cycle.

Study the graph given below and answer the questions that follow.

(i) Name the hormones 'X' and 'Y'.
(ii) Identify the ovarian phases during menstrual cycle.
(a) 5th-12th day of the cycle.
(b) 14th day of the cycle.
(c) 16th-25th day of the cycle.
(iii) Explain the ovarian events (a), (b) and (c) under the influence of hormones 'X' and 'Y'