CBSE Class 7 Answered

Self pollination

Cross pollination

The pollen grains from a flower are carried to the stigma of the same flower or on the other flower of the same plant.

The pollen grains from a flower are carried to the stigma of the flower on other plant.

Such flowers do not need any pollinating agent.

Such flowers need pollinating agents.

Self pollination is less preferable from the genetical point of view since there is no mixing of genes.

Cross pollination is more preferable from the genetical point of view since new characters can be be produced.

The flowers need not spend energy on producing showy flowers or large number of pollens.

The flowers need to spend large amounts of energy on producing large, showy flowers to attract pollinators as well as large number of pollens.