Question

Xenogamy is
A. Pollination between two flowers of two different plants
B. Pollination between two different flowers of the same plant and same branch
C. Pollination between anther and stigma of the same flower
D. A mechanism of parthenocarpy

Answer 1

Pollination is the process by which are produced from the anther or the male reproductive organ to the stigma which is a part of the female reproductive structure or the pistil in angiosperms. The pollination can be of two types, either self-pollination or cross-pollination, depending on the location of the flowers between which pollination occurs.

Step by step answer: Xenogamy is also known as cross-pollination. Here the transfer occurs between two genetically dissimilar flowers belonging to different plants. Here the pollen grains produced from the anther of one flower is transferred to the stigma of another flower of a different plant. This type of pollination helps in generating variations. Considering the other given options:
The process by which the pollination occurs between two different flowers present in the same plant in the same branch is known as geitonogamy. It is also a kind of self-pollination since the reproduction occurs between genetically similar flowers borne on the same plant. The process by which pollination occurs between the anther and stigma of the same flower is known as Autogamy. It is self-pollination and helps in maintaining the pure-line of breeding. But the chances for inbreeding depression to occur is more. Here the anther and the stigma are located nearby and the need for pollinating agents is generally not required.
Parthenocarpy is the development of fruits without the fertilization of ovules. It helps in producing seedless fruits. This method is commonly employed by horticulturists these days.
Thus the most appropriate answer is A.

Note: The pollination process is aided by certain biotic and abiotic agents known as the pollinating agents. It is required in the cases of xenogamy and geitonogamy. The abiotic agents are water and wind and the biotic pollinators are animals and birds. These agents transfer the pollen grains from one flower to the other.