Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

How has DDT caused decline in bird population?

For production of edible vaccines plants are used. Explain this any one example.

Human activities interfere with carbon cycle. List any two such activities.

Why is it essential that tRNA binds to both an amino acid and an mRNA codon during protein synthesis?

From what you have learnt, can you tell whether enzymes are bigger or DNA is bigger in molecular size? How did you know?

Describe the mutual relationship between fig. tree and wasp and comment on the phenomenon that operates in their relationship.

In a flower, the megaspore mother cell of an ovule forms megaspores by mitosis. If one of these megaspores develops into the embryo sac, what will be the ploidy of its (eight) nuclei?

A moss plant produces a large number of antherozoids but relatively only 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?

Answer the following questions:
Where do the signals for parturition originate from in humans?