In: Biology
1) Self-pollination would be avoided by all except which of these mechanisms?
a)Pollen is released before the stigma in the same flower is ready
b)Plants recognize and reject their own self-pollination (S-gene) alleles.
c)Plants are dioecious
d)Pollinator only visits flowers of the same species when they are in bloom
1) Self-pollination takes place in monecious plants. In the plant species which has the staminate and pistillate flowers in the same individual.
It can be avoided if a) Pollen is released before the stigma in the same flower is ready. In this case, pollen will not be liable for the time when the stigma matures, also it will not be able to reach its ovary.
b) Plants can recognize their own self-pollination and reject it can be seen in the phenomena called self-incompatibility (SI). It is one of the most efficient mechanisms to promote out-crossing in plants. In this case, self-pollination is avoided.
c) Since the event self-pollination occurs in the monecious plants, it is unlikely that a dioecious plant can self-pollinate. The dioecious plants have both male and female sexes. In them, the flowers they carry of different sex are in different plants. In this case, self-pollination is avoided.
d) Pollinator only visits flowers of the same species when they are in bloom. In this case, self-pollination would not be avoided. Here the animal pollinators can visit the same species and its different flowers from different plants. Geitenogamy is one of the examples where this is done, and it is a type of self-pollination. Here the self-pollination can occur.