Which one of the following statements explains autogamy?

The correct answer is Option (1) → Pollination is achieved within the same flower.

Option (1) Pollination is achieved within the same flower. — Correct. “Auto” means self. In autogamy the pollen never leaves its own flower. Cleistogamous flowers of Viola, Oxalis and Commelina, which never open, can only be autogamous.

Option (2) Transfer of pollens from one flower to another. — Incorrect. Once the pollen goes to another flower, it is no longer autogamy. It is geitonogamy or xenogamy.

Option (3) Transfer of pollens from the anther to the stigma of another flower of the same plant. — Incorrect. This is geitonogamy. It needs a pollinating agent like cross-pollination, but genetically it is like self-pollination because both flowers are on one plant.

Option (4) Transfer of pollens from stigma to anther of a different plant. — Incorrect. Pollen always moves from the anther to the stigma, never from the stigma. Transfer to the stigma of a different plant would be xenogamy.

NCERT Extract:
Pollination – …