CBSE Class 10 Answered

In self-pollination, pollen grains are transferred from the anther to the stigma of the same flower or another flower on the same mother plant. In cross-pollination, pollen grains of one flower of one plant are transferred to the stigma of the flower on another plant . Thus it involves 2 plants.

In self-pollination, the flowers do not have to depend on external agencies for pollination, whereas in cross-pollination, the plants ahev to depend on various external agencies, which may not be fully effective at times.

In self-pollination, there is no expenditure of energy on part of the plant in producing elaborate devices like nectaries, bright colours etc.  In cross-pollination, there is expenditure of energy on part of the plant in producing elaborate devices like nectar, bright colours, pleasant fragrance etc.

Self-pollination is more economical since there is no wastage of pollen grains and quantity of pollen grains required is comparatively less. There is no wastage of pollen grains especially in wind-pollinated plants.

Cross-pollination may develop undesirable characters in the progeny. The offsprings produced are genetically pure from generation to generation and hence there is hardly any chance of undesirable characters developing in offsprings.

Continuous self-pollination results in weaker progeny, whereas cross-pollination promotes racial vigour by producing healthier offsprings.

There is no possibility of variations in self-pollination. There is possibility of variations in cross-pollination.