Question

Write the events involved in the sexual reproduction of a flowering plant.

a. Discuss the first event and write the types.

b. Mention the advantages and the disadvantages of that event.

Answer 1

a. The first event is pollination. Pollination is the process of transfer of pollen grains from another to the stigma of a flower. The two types of pollination are self-pollination and cross-pollination.

b. Advantages of self-pollination:

1. Self-pollination is possible in certain bisexual flowers.
2. Flowers do not depend on agents for pollination.
3. There is no wastage of pollen grains.

Disadvantages of self-pollination:

1. The seeds are less in numbers.
2. The endosperm is minute. Therefore, the seeds produce weak plants.
3. New varieties of plants cannot be produced.

Advantages of cross-pollination:

1. The seeds produced as a result of cross-pollination, develop and germinate properly and grow into better plants, i.e., cross-pollination leads to the production of new varieties.
2. More viable seeds are produced.

Disadvantages of cross-pollination:

1. Pollination may fail due to distance barriers.
2. More wastage of pollen grains.
3. It may introduce some unwanted characters.
4. Flowers depend on external agencies for pollination.