Question

Make a list of any three outbreeding devices that flowering plants have developed and explain how they help to encourage cross-pollination.

Answer 1

(i) Production of unisexual flowers/dioecious plants, cross pollination ensured. 

(ii) Self incompatibility, genetic mechanism prevent the pollen germination on the stigma of the same flower. 

(iii) Anther and stigma are placed at different positions, so the pollen can not come in contact with the stigma of the same flower.