Question

What are chasmogamous flowers? Can cross-pollination occur in
cleistogamous flowers? Give reasons for your answer.
Mention two strategies evolved to prevent self-pollination in flowers.​

Answer 1

Explanation:

There are two types of flowers present in plants namely Oxalis and Viola − chasmogamous and cleistogamous flowers. Chasmogamous flowers have exposed anthers and stigmata similar to the flowers of other species.

Cross-pollination cannot occur in cleistogamous flowers. This is because cleistogamous flowers never open at all. Also, the anther and the stigma lie close to each other in these flowers. Hence, only self-pollination is possible in these flowers.

2) The strategies evolved to prevent self-pollination in flowers are:

1) Dichogamy- The maturation of anthers and stigma at different time in a bi-sexual flower which prevents self-pollination.

2) Self-incompatibility: The pollen grains of a flower are not capable of completing growth on the stigma of the same flower.

Answer 2

Answer:

1. Chasmogamous flowers have exposed anthers and stigmata similar to the flowers of other species.  
2. Cross-pollination cannot occur in cleistogamous flowers. This is because cleistogamous flowers never open at all. Also, the anther and the stigma lie close to each other in these flowers. Hence, only self-pollination is possible in these flowers.
3. The strategies evolved to present self-pollination in flowers are:

1)dichogamy- the maturation of anthers and stigma at different time in a bi-sexual flower which prevents self pollination.

2) self- incompatibility : The pollen grains of a flower are not capable of completing growth on the stigma of the same flower.