Question

The condition of maturation of stigma before anthers of the same flower is:
A) Protandry       
B) Herkogamy
C) Protogyny  
D) Prepotency

Answer 1

Hint: For fertilization to occur in plants effectively, it is imperative for the male and female to be easily accessible to each other, to mature in the same time period before they can no longer be fertilized. fertilization can occur by pollination which is of two types: cross pollination and self pollination.
Step by step solution:
Flowering plants make some significant changes to encourage cross-pollination. Dichogamy is one of the modifications. The anthers mature at various dates and have a stigmatic state. Protandry is the term for when the anthers develop before the stigma. In Sunflower, this condition is present. In contrast, protogyny is a state when the female sex organs mature before the male sex organs, as observed in potato flowers.
Herkogamy in self-compatible plants is typically seen as an adaptive trait that lowers the likelihood of self-pollination and raises the possibility of outcrossing, but it may serve solely to limit sexual interference in self-incompatible species.
Prepotency is the capacity of an individual to germinate faster in the case of cross pollination than in self pollination.
Hence, option C is the correct answer.
Note:
The primary distinction between dichogamy and herkogamy is that the former refers to presence of both the sexes in the same plant but positioned spatially at a distance. Dichogamy on the other hand, refers to an uncoordinated time of maturation of female and sex organs. Thus, both the mechanisms prevent self-fertilization.