Human Reproduction — BIOLOGY STD 12 Science — Question

Given below are the events that are observed in artificial hybridisation programme. Arrange them in the correct sequential order in which they are followed in the hybridisation programme.
(a) Re-bagging; (b) Selection of parents; (c) Bagging; (d) Dusting the pollen on stigma; (e) Emasculation; (f) Collection of pollen from male parent.

Differentiate between : (i) Epicotyl and hypocotyl, (ii) Coleoptile and coleorrhiza, (iii) Integument and testa, (iv) Perisperm and pericarp

Write a note on the vector relationship for gene cloning in plants and animals.

Prior to a sports event blood & urine samples of sportspersons are collected for drug tests.

1. Why is there a need to conduct such tests?
2. Name the drugs the authorities usually look for.
3. Write the generic names of two plants from which these drugs are obtained.

Seeing a crowd of students in one corner of the school, the principal rushed to see the matter and found some children beating and chasing a small lizard. On seeing the principal, all the children fled to their classes except Alok who requested the principal to arrange for some medical assistance for the injured animal. The principal rewarded Alok for his attitude to save guard our biodiversity.

1. Mention the factors resulting in loss of biodiversity
2. Was Alok an indisciplined boy, who did not run to the class on seeing the principal? What values does the act promote?

In which phase of menstrual cycle is corpus luteum formed?

Where does fertilisation normally take place in a human female?

What are called pathogens? Give information about it? (with example).

Recently a girl baby has been reported to suffer from haemophilia. How is it possible? Explain with the help of a cross.