During reproduction, the chromosome number (2n) reduces to half (n) in the gametes and again the original number (2n) is restored in the offspring. What are the processes through which these events take place?
Halving of chromosomal number takes place during gametogenesis and regaining the 2n number occur as a result of fertilisation.
Give the names and functions of the hormones involved in the process of spermatogenesis. Write the names of the endocrine glands from where they are released.
A human female experiences two major changes, menarche and menopause during her life. Mention the significance of both the events.
Meiotic division during oogenesis is different from that in spermatogenesis. Explain how and why?
During reproduction, the chromosome number (2n) reduces to half (n) in the gametes and again the original number (2n) is restored in the offspring. What are the processes through which these events take place?
The mother germ cells are transformed into a mature follicle through series of steps. Provide the missing steps in the blank boxes.
Name the functions of the following:
(a)Corpus luteum (b) Endometrium
(c)Acrosome (d) Sperm tail
(e) Fimbriae
What is the significance of ampullary-isthmic junction in the female reproductive tract?
Match the following and choose the correct options:
Options:
(a) A—ii, B—i, C—iii, D—iv (b) A—iii, B—iv, C—ii, D—i
(c) A—iii, B—i, C—ii, D—iv (d) A—ii, B—iv, C—iii, D—i
(a) How many spermatozoa are formed from one secondary spermatocyte? (b) Where does the first cleavage division of zygote take place?
What role does pituitary gonadotropins play during follicular and ovulatory phases of menstrual cycle? Explain the shifts in steroidal secretions.
Female reproductive organs and associated functions are given below in column A and B. Fill in the blank boxes.
During reproduction, the chromosome number (2n) reduces to half (n) in the gametes and again the original number (2n) is restored in the offspring. What are the processes through which these events take place?
What are the events that take place in the ovary and uterus during follicular phase of the menstrual cycle?
In our society the women are often blamed for giving birth to daughters. Can you explain why this is not correct?
How many eggs are released by a human ovary in a month? How many eggs do you think would have been released if the mother gave birth to identical twins? Would your answer change if the twins born were fraternal?
Corpus luteum in pregnancy has a long life. However, if fertilisation does not take place, it remains active only for 10-12 days. Explain.
How many eggs do you think were released by the ovary of a female dog which gave birth to 6 puppies?
Match between the following representing parts of the sperm and their functions and choose the correct option.
Options:
(a) A”ii, B”iv, C”i, D”iii
(b) A”iv, B”iii, C”i, D”ii
(c) A”iv, B”i, C”ii, D”iii
(d) A”ii, B”i, C”iii, D”iv
From where the parturition signals arise”mother or foetus? Mention the main hormone involved in parturition.
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 synthesize androgens. (True/ False)
(e)Oogenesis takes place in corpus luteum. (True/False)
(i) 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)
Fill in the blanks:
(a)Humans reproduce————— (asexually/sexually).
(b)Humans are————— (oviparous, viviparous,ovoviviparous).
(c)Fertilization 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 a mature follicle is called————— .
(g)Ovulation is induced by a hormone called—————
(h)The fusion of male and female gametes is called————— .
(i)Fertilization 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————— .
Given below are the events in human reproduction. Write them in correct
sequential order: Insemination, gametogenesis, fertilisation, parturition, gestation, implantation
Given below is a flow chart showing ovarian changes during menstrual cycle. Fill in the spaces giving the name of the hormones responsible for the events shown.
