Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Co-evolution is a spectacular example of mutualism between an animal and a plant. Describe co-evolution with the help of an example.

Write the important functions of various reproductive organs of human female.

1. Match the microbes listed under Column-A with the products mentioned under Column-B.

	Column-A		Column-B
(a)	Penicillium notatum	(i)	Statin
(b)	Trichoderma polysporum	(ii)	Ethanol
(c)	Monascus purpurea	(iii)	Antibiotic
(d)	Saccharomyces cerevisiae	(iv)	Cyclosporin-A

2. Why does ‘Swiss Cheese’ develop large holes?

How is pollination carried out in water plants?

The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?

What is sex determination? Explain the mechanism of sex determination in birds.

Describe three manners in which fertilisation of human ovum by a sperm can be prevented.

Describe the mechanism of inheritance of the ABO system of blood groups, highlighting the principle of genetics involved in it.

Following the collision of two trains, a large number of passengers are killed. A majority of them are beyond recognition. Authorities want to hand over the dead to their relatives. Name a modem scientific method and write the procedure that would help in the identification of kinship.

Name the two end products of double fertilization in angiosperms. How are they formed? Write their fate during the development of seed.