Describe any two devices in a flowering plant which prevent both autogamy and geitonogamy?
Autogamy: It is the transfer of pollen grains from the anther to the stigma of the same flower. Geitonogamy: It is the transfer of pollen grains from the anther to the stigma of another flower of the same plant. Two devices that prevent both autogamy and geitonogamy are: (a) Self-incompatibility: This is a genetic mechanism which prevents self pollen from fertilising the ovules by inhibiting pollen germination or growth of pollen tube in the pistil. (b) Dioecious plants: Male and female flowers are present on different plants.
