Question

define cross and self pollination.......

Answer 1

Cross pollination is the transfer of pollen grains from the anther of a flower to the stigma of a flower of a different plant of the same species.

Self pollination is the transfer of pollen grains from the anther to the stigma of the same flower.

Answer 2

When the stamen of the flower falls on its own stigma then it is called self pollination
when the stamen of the flower falls to the another flowers stigma then it is called cross pollination