Question

exact defination of self pollination​

Answer 1

Self-pollination is when pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). ... Some plants have mechanisms that ensure autogamy, such as flowers that do not open (cleistogamy), or stamens that move to come into contact with the stigma.

Answer 2

the transfer of pollen from the anther to the stigma of the same flower, another flower on the same plant, or the flower of a plant of the same clone.