Autogamy vs Geitonogamy vs Xenogamy — Same Plant Different Flower = Geitonogamy

Pollination types differ by source of pollen. Autogamy: pollen transfers from anther to stigma of the SAME flower — requires synchrony in pollen release and stigma receptivity. Geitonogamy: pollen transfers from anther to stigma of a DIFFERENT flower on the SAME plant — genetically equivalent to autogamy but functionally acts like cross-pollination. Xenogamy: pollen transfers to a flower of a DIFFERENT plant — the only type involving genetically different pollen.

In a typical NEET question on this concept, the question was: "Match the type of pollination with its correct description:" The correct answer is A — A-II, B-III, C-I, D-IV.

Common wrong answer: Transfer of pollen to a flower on the same plant is called autogamy. Correct: Same plant, DIFFERENT flower = GEITONOGAMY. Same flower = autogamy. Different plant = xenogamy.

GEITO = Greek for neighbour. Geitonogamy = neighbouring flower on SAME plant. Different plant = XENO (foreign) = xenogamy. Key fact: Autogamy: same flower — pollen to stigma within the same flower. Common in cleistogamous flowers.

(1) Autogamy: same flower — pollen to stigma within the same flower. Common in cleistogamous flowers. (2) Geitonogamy: different flower, same plant — genetically = self-pollination despite physical cross-pollination. (3) Xenogamy: different plant — only type that introduces new genetic combinations (TRUE cross-pollination).