B.

gives high yield nd is rich in vitamin-A

Golden rice is a variety of Oryza sativa produced through genetic engineering to biosynthesize beta- carotene, a precursor of pro-vitamin-A in the edible parts of rice. The research that led to golden rice has been bred to be especially. disease- resistant, resulting in better crop yields.

A.

medium water conditions

Hydrarch succession takes place in water areas and the successional series progress from hydric to the mesic conditions. As against the xerarch succession takes place in dry areas and series progress from xeric to mesic conditions. Hence, both hydrarch and xerarch succession lead to medium water conditions (mesic)-neither too dry (xeric) nor too wet (hydric).

A.

liposoluble

Many pesticides, such as DDT, aldrin and dieldrin are accumulated in the environment. They are fat soluble and generally non-biodegradable, They get incorporated into the food chain and ultimately deposited in the fatty tissue of animals and humans. In the food chain because of their build up, they get magnified in the higher trophic levels called biological magnification. The phenomenon of biological magnification is also reported of certain other pollutants such as heavy metals.eg, mercury, copper and radioactive substances as strontium-90

A.

senescent leaves

Deficiency of both nitrogen (N) potassium (K) visible in senescent (older) leaves i.e., due to the deficiency symptoms of N  chlorosis while, the deficiency of cause the inhibition of protein synthesis and scorching of older leaves.

A.

methane, hydrogen sulphide and carbon dioxide

Biogas is a mixture of gases (mainly methane) produced by the microbial activity and which may be used as fuel. During biogas production, the bacteria called methanogens digest the activated sludge and produce a mixture of gases such as methane, hydrogen sulphide, carbon dioxide and hydrogen.