Question

Transfer of pollen grain from the anther to the stigma of another flower of the same plant is called:
A. Xenogamy
B. Geitonogamy
C. Karyogamy
D. Autogamy

Answer 1

Hint: Pollen is a powdery substance made up of pollen grains, which are male microgametophytes that produce male gametes in seed plants (sperm cells). The gametophytes are protected by a hard coat of sporopollenin on pollen grains as they move from the stamens to the pistil of flowering plants or from the male cone to the female cone of coniferous plants.

Complete answer:
Pollen grains are microscopic structures that contain androecium, a flower's male reproductive organ. The tube cell converts into a pollen tube and the generative cell releases the sperm nuclei in the interior section of the pollen grain, which contains cytoplasm.
Pollen grains consist of three parts:
During fossilization, the inside of the cell, which is filled with living cytoplasm, deteriorates rapidly.
The inner layer of the cell wall, intine, is made up of cellulose and pectin. The intine, like the cytoplasm, degrades rapidly during fossilization.
Exine, the cell wall's outer layer, is mostly made up of sporopollenin. It is one of the most durable materials. It's an N-free polymeric substance that belongs to the terpene family of organic compounds.
Pollination is the process of pollen grains being transferred from the anther to the stigma of a pistil. It's the process of bringing non-motile male and female gametes together for fertilization. Self-pollination occurs when pollen grains from the anther fuse with the stigma of the same flower or with the stigma of a different flower on the same plant. There are two types of self-pollination: autogamy and geitonogamy.
Geitonogamy is the transfer of pollen grains from one flower's anther to the stigma of another flower on the same plant. A pollination agent is used in this transfer. Because the pollen grains come from the same plant, it is genetically similar to autogamy.

As a result, option D is the correct answer.

Note:
Within wind-pollinated species, geitonogamy is also possible, and it may be a common source of self-fertilized seeds in self-compatible species. Monoecious gymnosperms also have it. Although geitonogamy is technically cross-pollination with the use of a pollinating agent, it is genetically similar to autogamy because the pollen grains are from the same plant.