Question

odd one out and give reasons for other
Herkogamy, dichoyamy, cleistogamy, Heterostyly​

Answer 1

Answer:

cleistogamy

Explanation:

Cleistogamy is not a device to promote cross-pollination as the flowers remain closed and they promote self-pollination. For example, Balsam, Oxalis and Viola anthers dehisce inside closed flowers.  

Herkogamy, dichogamy and heterostyly are the devices which promote cross-pollination. Herkogamy is a mechanical device to prevent self-pollination. For example in Pansy, stigma lies inside a flap.

In dichogamy, anthers and stigma mature at different times which ensures cross-pollination. When anthers mature earlier, it is known as protandry as in sunflower and when stigmas mature earlier it is known as protogyny as in Gloriosa.

In heterostyly, there are 2 or 3 different types of flowers with different heights of stamens and stigmas which prevent self-pollination as in jasmine.  

Thus, the correct answer is option C.