Question

Which of the following mechanism favours self-pollination ?

• A. Protandry
• B. Cleistogamy
• C. Protogyny
• D. Dioecy

Hint:

Mechanisms influencing pollination type:
Favouring Self-Pollination:
Cleistogamy: Flowers never open, ensuring self-pollination (e.g., some violets, peas).
Bisexual flowers where anthers and stigma mature simultaneously and are close.
Favouring Cross-Pollination:
Protandry (anthers mature first).
Protogyny (stigma matures first).
Dioecy (separate male and female plants).
Self-incompatibility.

Answer 1

The Correct Option is B

Step 1: Protandry and protogyny stagger anther/stigma maturity to favour cross-pollination, not self-pollination.
Step 2: Dioecy separates male and female flowers onto different plants, also forcing cross-pollination.
Step 3: Cleistogamy keeps flowers closed, so only self-pollen can reach the stigma.
Step 4: Correct answer: Cleistogamy.