Advertisements
Advertisements
प्रश्न
The normal body cell of an organism contains 28 pairs of chromosomes. The number of chromosomes present in its germ cell will be:
विकल्प
28
14
56
42
Advertisements
उत्तर
14
Explanation:
A germ cell has 14 pairs of chromosomes, i.e., half the number of chromosomes present in the normal body cell of an organism.
संबंधित प्रश्न
State the changes that take place in the uterus when Female gamete/egg is not fertilised
Give a biological explanation for the following.
The placenta is an important structure for the development of a foetus.
Where in the human body does an ovum get fertilised?
Why is it an advantage for the testes to be situated in the scrotal sac outside the main body cavity? Can you think of one disadvantage?
When a fertilised egg E formed in the oviduct of a human female divides repeatedly to form an embryo, the embryo gets implanted in the thick and soft lining of the uterus. After this a disc-like special tissue T develops between the uterus wall and embryo through which all the requirements of the developing embryo (and foetus) are met from the mother's body, The embryo is connected to the tissue T through a string like structure S.
(a) What is the other name of fertilised egg cell E?
(b) What is the name of tissue T?
(c) Name the string-like structure S.
(d) Name two substances which pass from mother's blood to embryo through tissue T and, one type of substance which passes from embryo to mother's blood.
(e) What happens to S when the baby is born? Why?
Describe in brief the role of prostate gland in human male reproductive system.
List two changes observed in girls at the time of puberty.
Give the names:
Any two sexual diseases.
The following is the illustration of the sequence of ovarian events (a-i) in a human female.
Write the difference between C and H.
