Correct option is C
Correct Answer:
Option (3) — To increase reproductive success in response to uncertainty in pollination
Explanation:
-Cleistogamous flowers are closed, self-pollinating flowers that ensure reproduction even when pollinators are absent or environmental conditions are unfavorable for cross-pollination.
-Plants that produce both cleistogamous (self-pollinating) and chasmogamous (open, cross-pollinating) flowers adopt a mixed reproductive strategy to guarantee reproductive success under variable conditions.
-Thus, the evolution of cleistogamous flowers enhances reproductive assurance when pollination by external agents is uncertain.
Information Booster:
-Cleistogamy: Self-pollination within closed flowers → guarantees seed set even without pollinators.
-Chasmogamy: Open flowers that allow cross-pollination → increases genetic diversity.
-Examples: Viola, Oxalis, Commelina benghalensis, Impatiens balsamina.
-Adaptive advantage: Plants can reproduce both under favorable (cross-pollination) and unfavorable (self-pollination) conditions.
Additional Knowledge (Incorrect Options Explained):
(1) Incorrect — Cleistogamy promotes inbreeding, not avoidance of inbreeding depression.
(2) Incorrect — Cleistogamy ensures self-pollination, not cross-pollination.
(4) Incorrect — Cleistogamous flowers are closed and inconspicuous, so they do not attract pollinators.
