Question

Mention two strategies evolved to prevent self-pollination in flowers.

Answer 1

Self-pollination:

1. Self pollination is transfer of pollen from the anther to the stigma of the same flower.
   
2. Some plants have evolved in such a way that they have mechanisms to prevent self pollination and promote cross pollination even in the presence of bisexual flowers.
3. Two strategies evolved to prevent self-pollination are pollen release time and hypogynous flower.
   
4. Pollen release and stigma receptivity is not synchronized, which means when the pollens are released the stigma is not receptive enough for the pollen to stick to the stigma.
   
5. Hypogynous flower: The type of flower in which gynoecium is higher as compared to androecium is called hypogynous flower.
   
6. In this type of flower the chance of pollen from the anther reaching the stigma is very low, which induces cross pollination.