Human Health and Diseases — BIOLOGY STD 12 Science — Question

The following statements (i), (ii) and (iii) seem to describe the water-pollinated submerged plants. Which one of these statements is incorrect?

1. The flowers do not produce nectar.
2. The pollen grains have mucilaginous covering.
3. The brightly-coloured female flowers have long stalks to reach the surface.

Explain (in one or two lines) the function of the following:
Promoter.

How many amino acids are required for protein synthesis? From where are they obtained?

Gene flow

What is dairying?

Why is respiration in insect called direct respiration?

Describe external structure of root hair.

Name the two forms of extinct reptiles that evolved from synapsids.

What are the types of tissue culture based on the type of in vitro growth?

Name the cartilage which divides the nasal cavity into right and left nasal chambers.