Question

When pollen grain is shed at 3-celled stage, name the cells it contains
A. 1 vegetative cell and 2 male gametes
B. 2 vegetative cell and 1 male gametes
C. 2 generative cells and 1 male gametes
D. 2 male gametes and 1 generative cell

Answer 1

Hint: Pollen grains are the fine structures which carry the male reproductive cells of the plant. In the angiosperm plants, it is produced by the anthers of the stamens of flowers. It is dispersed by wind, water, birds etc.

Complete Answer:
- It usually appears as fine dust. Each pollen grain varies in shape and structure. It is found in the male structure of the angiospermic plant. In gymnosperm it is found in male cones. Pollen itself is not a male gamete. It comprises one or more vegetative cells and a reproductive cell.
- The vegetative cells form the pollen tubes and the reproductive cells form 2 male sperms.
- Parts of pollen grains: It consist of 3 distinct parts: The cytoplasmic part contains the nuclei which take part in fertilisation, the outer layer which is resistant to adverse conditions called the exine and the inner layer called the intine.

Thus the correct answer is (A). Pollen cells contain 2 male gametes and 1 vegetative cell.

Note: The vegetative cells do not take part in reproduction. It rather forms a pollen tube which grows to meet unfertilised ovules. The generative cell divides into two sperm cells.