question_answer 29)

  Choose the correct statement from the following. (a) Cleistogamous flowers always exhibit autogamy.       (b) Chasmogamous flowers always exhibit geitonogamy. (c) Cleistogamous flowers exhibit both autogamy and geitonogamy. (d) Chasmogamous flowers never exhibit autogamy.

Answer:

                (a)The pollination that occurs in opened flowers is called chasmogamy. It is the most common type of pollination in all types of flowers. Chasmogamy is of two types i.e., self-pollination (autogamy) and cross-pollination. Cross-pollination is of two types i.e., geitonogamy and xenogamy. So, we can say that chasmogamous flowers exhibit both autogamy (self-pollination)and allogamy (cross-pollination). While, in Cleistogamous flower the anthers and stigma lie close to each other with in the closed flowers. When anthers dehisces in the flower buds, pollen grains come in contact with the stigma for effective pollination. Thus, these flowers are invariably autogamous as there is no chance of cross-pollen landing on the stigma.