Question

Mention the strategies evolved to prevent self-pollination?

class 12th CBSE Biology sample paper

Answer 1

1) Some species i.e., pollen grains are released before its own stigma becomes receptive (protandry) while in some other the pistil mature earlier then the anther or release of pollen grains (protogyny).

2) self-incompatibility - It is a genetic mechanism to prevent self pollination.

Answer 2

A few kinds of flowers are self-pollinating; that is, they can be fertilized with their own pollen. In most cases, however, nature takes great care to prevent self-pollination. Cross-pollination usually produces more vigorous plants. This requires the transfer of pollen from one plant to the stigma of another plant of the same species.

Flowers avoid self-pollination in several ways. In some cases the stamens and pistils mature at different times. In other flowers the stamens…

hope it will help you