Q.Define pollination and differentiate between autogamy and geitonogamy.

Geitonogamy needs a pollinating agent but is genetically equivalent to self-pollination.

Pollination is the process by which pollen grains are transferred from the anther of a stamen to the stigma of a carpel, enabling fertilisation to follow.

Autogamy is self-pollination in the strictest sense: pollen is transferred from the anther to the stigma of the very same flower. It requires that the anthers and stigma of that flower mature at the same time and be positioned close enough for pollen to reach the stigma without any external agent, though a pollinator may sometimes assist.

Geitonogamy is pollen transfer from the anther of one flower to the stigma of a different flower borne on the SAME plant. Structurally it requires a pollinating agent (wind, insect, etc.) just like cross-pollination between two different plants, but genetically it is equivalent to self-pollination, because both flowers carry the identical genotype of one individual plant.

Define pollination first, then separate autogamy (one flower) from geitonogamy (two flowers, one plant) and note geitonogamy's dual nature (mechanism vs genetics).

Calling geitonogamy a form of cross-pollination just because it needs a pollinator -- genetically it behaves exactly like self-pollination since the source plant is identical.