When the pollers is transferred from anther to stigma of same flower, the pollination is called autogamy.
(a) Cleistogamous flowers are invariably autogamous. Explain.
(b) Geitonogamy is functionally cross pollination, but genetically similar to autogamy. Identify the statement. (Kerala Board 2017)

Explanation

(a) Cleistogamous flowers remain closed with anthers and stigma lying close to each other. When the anthers dehisce, the pollen grains come in contact with stigma, pollination takes place. Thus, cleistogamy leads to self-pollination making cleistogamous flowers invariably autogamous
(b) Geitonogamy is transfer of pollen grains from anthers of one flower to stigma of another flower of either the same or genetically similar plant. It resembles cross-pollination as it needs a pollinating agency for transfer of pollen grains.
Thus, geitonogamy is functionally cross-pollination but genetically like autogamy.