Question

Describe two devices by which cross pollination encouraged in angiosperms by avoiding self pollination

Answer 1

Answer:

Herkogamy: It is a mechanical device to prevent self-pollination in a bisexual flower. In plants, a natural physical barrier is present between two sex organs and avoid contact of pollen with the stigma of the same flower, in e.g. Calotropis, pentangular stigma is positioned above the level of anthers (pollinia).