Question

Autogamy can occur in a chasmogamous flower if
A. Pollen matures before the maturity of the ovule
B. Ovules mature before the maturity of pollen
C. Both pollen and ovules mature simultaneously
D. None of the above

Answer 1

Pollination is a mechanism where pollen grains are transferred from the anther to the stigma. Pollen grains are identified as immobile elements. Self-pollination can be defined as the process where the pollen grains from the anther of a flower is transferred to the stigma of the same flower. Autogamy and geitonogamy are the two types of self-pollination.

Complete answer: Autogamy is a sub-class of self-pollination and takes place in an intersexual or perfect flower. Here, the flower gets pollinated by its own pollen. Homogamy is one of the methods of autogamy. Homogamy occurs in chasmogamous or open flowers. By the mechanism of growth, bending, and folding the anthers and stigmas of these flowers are brought together. In the case of Catharanthus , when the style grows the stigma comes in contact with the ripe anthers that are present on the mouth of the corolla tube. In Four O’clock flowers, the ripe anthers and the stigma come in close contact due to the bending of the filaments. Curling of styles brings the stigma close to the ripe anthers in potato flowers. If the cross-pollination fails in Sunflower, the stigma picks the pollen sticking to the surface of the style by curling back. This phenomenon is referred to as a fail-safe mechanism of self-pollination. Hence, autogamy (homogamy) is performed by chasmogamous flowers when both pollen and ovules mature simultaneously.
Thus, the correct option is C, i.e., Both pollen and ovules mature simultaneously.

Note: Homozygosity can be achieved with the help of homogamy. The flowers are prominent in chasmogamous flowers. The daughter flowers receive a specific gene from each of the parents. As a result, the daughter flowers have two same formats of that gene.