Question

Write the two events involved in the sexual reproduction of flowering plants
a) Discuss the first event and write the types.
b) Give advantages and disadvantages of that event.

Answer 1

The sexual reproduction in flowering plants involves-
a) Pollination
b) Fertilization
a) Pollination: Transfer of pollen grains from the anther to the stigma of a flower is called pollination. Pollen grains are transferred by agents like air, water, insects etc.
Types of pollination
Self-pollination (Autogamy): When the pollen grains are transferred from the anther of a flower to the stigma of the same flower or another flower of the same plant it is known as self-pollination.
Cross-pollination (Allogamy): When the pollen grains are transferred to the stigma of another flower of a different plant it of the same species it is known as cross-pollination.

b) Advantages self-pollination
1. Self-pollination is certain in bisexual flowers.
2. Flowers need not depend on agents.
3. No wastage of pollen grains.
Disadvantages of Self-pollination
1. Seeds are less in number.
2. Seeds produce weak plants due to minute endosperm.
Advantages of cross-pollination
1. It leads to the production of new varieties.
2. More viable seeds are produced.
Disadvantages of cross-pollination

1. Plants have to depend on agents for pollination.
2. Wastage of Pollen grains occurs.