Question

When the pollen of a flower is transferred to the stigma of another flower of the same plant the pollination is referred to as-
A) Autogamy
B) Allogamy
C) Xenogamy
D) Geitonogamy

Answer 1

Hint: We know that in flowering plants both the male and female gametes are produced in the pollen grain and embryo sac respectively. But both of these gametes are non-motile and they need to be brought together for fertilization.

Complete answer:
The transfer of pollen grains to the stigma of the pistil is called pollination. Pollination can be of two types are self-pollination and cross-pollination.
A) Autogamy- In this type, the pollen grain of a flower is transferred to the stigma of the same flower.
B) Allogamy- In this type, the pollen grain from the answer of the flower is transferred to the stigma of the other flower of a different plant of the same species. It is also called cross-pollination.
C) Xenogamy- In this type, the pollen grain gets transferred to the stigma of the different plants. This is the only type of pollination that brings a genetically different type of pollen grains to the stigma of the flower.
D) Geitonogamy- In this type of pollination the pollen grain of a flower gets transferred to the stigma of another flower of the same plant.
Thus, option D is the correct answer.

Note: Complete autogamy is rare because it requires synchrony of pollen release and stigma respectively at the same time. The main difference between Xenogamy and Allogamy is, Xenogamy transfers the pollen grain from the anther of one flower to the stigma of a genetically different flower of the same species. Whereas in allogamy the transfer of pollen grain takes place from the anther of one flower to the stigma of another flower either in the same plant or a different plant of the same species.