Question

Assured seed set is possible even in absence of pollinators when the flower is
A. Xenogamous
B. Chasmogamous
C. Geitonogamous
D. Cleistogamous

Answer 1

The pollens are found in the anther of the male part of the flower. The pollen will travel via stigma and style to have fusion with the female part of the cell. The resulting embryo is implanted there and is transported nutrition via endosperm formed by triple fusion.

Complete answer:
The pollen fuses with the egg cell to produce the embryo which will be the seed in the fruit. There are two types of pollination- self-pollination and cross-pollination. In the self-pollination, the male and female parts are nearby. In the cross-pollination, there is a requirement of a pollinator which will carry the pollen to the female flower part.

Option A: Xenogamous: The plants in which the pollen is transferred from one plant to the stigma of another plant. This is xenogamy. There is cross-pollination. This depends on external factors.

Option B. Chasmogamous: The flowers are open following the chasmogamous flowers. They can do the cross and self-pollination. The flowers depend on external factors for pollination.

Option C. Geitonogamous: The flower when do the self-pollination on the same plants are the geitonogamous.

Option D. Cleistogamous: It is the phenomenon where flowers never open, the stigma and anthers are placed very close to each other to enhance the self-pollination. They do not depend on the external factors for the pollination. So seed setting is not dependent on the pollinators.

Hence, the correct answer is option (D).

Note: In the absence of pollinators, the pollination still occurs. It occurs in flowers like Viola, peas etc. There are reduced sepals and petals in them. Nectars are also absent. They do not need pollinators to attract the pollinators to have the pollination.