Question

Mention any four strategies adopted by flowering plants to prevent self-pollination.

Answer 1

1. Dichogamy: The anthers and stigma mature at different times; they are not both receptive at the same time.
2. Herkogamy: Physical barriers or structural arrangements in the flower separate anthers and stigma (for example, in Calotropis).
3. Self-incompatibility: A genetically regulated system in which pollen from the same plant is unable to fertilize the ovule, preventing selfing (for example, Brassica).
4. Unisexuality (Dioecism): Self-pollination is impossible since distinct plants produce unisexual (male and female) flowers.