Question

Distinguish between Self-pollination and Cross- pollination.

Answer 1

pollination between two flowers of the same plant is called self pollination.
pollination between two flowers of the same species but of different plant is called cross pollination

Answer 2

The major differences between self-pollination and cross-pollination are, in cross-pollination the pollen grains are transferred from the anther of one plant to the stigma of another, increasing the gene pool whereas in self-pollination the pollen grains are transferred from the anther to the stigma of the same flower causing decrease in the gene pool.

Self-pollination occurs only in perfect flowers but cross-pollination will occur in imperfect flowers too.

Cross-pollination needs pollinators to transfer the pollen grains whereas in self-pollination pollinators are not required.