Enhancement of Food Production — BIOLOGY STD 12 Science — Question

Define auto-immune disease. Give two examples.

Why are plants obtained by protoplast culture called somatic hybrids?

List the features that make a stable biological community.

Mention the two major environmental issues of global nature.

A moss plant Produces a large number of antherozoids but relatively a few egg cells. Why?
OR
Why do moss Plants produce very large number of male gametes? Provide one reason what are these gametes called?

Identify A, B, C and D in the given table:

Crop	Variety	Resistance to disease
A-	Himgir	Leaf rust
Cauliflower	Pusa Shubhra	B-
Brassica	Pusa Swarnim	C-
Cowpea	D-	Bacterial blight

Give the types of human proteins and hormones produced by recombinant DNA techniques.

Rearrange the following in increasing order of evolution: Gnetales, Ferns, Zosterophyllum, Ginkgo.

A low level of expression of lac operon occurs at all the time. Can you explain the logic behind this phenomena.

Dust, Carbon monoxide, Lead, Smog, Methane, Mercury, DDT, Cadmium.

Column A	Column B (Examples)
(1) Particulate pollutant	__________________
(2) Gaseous pollutant	__________________
(3) Biomagnification	__________________
(4) Heavy metals	__________________