Question

State one advantage and one disadvantage of cleistogamy.

Answer 1

The plants are classified on the basis of several characteristics that includes; dicot and monocot, arrangement of sepal and petals, arrangement of tissue, shape and size of flowers, and the pollination technique; either self-pollination or cross-pollination.

Complete answer:
To answer this question, we have to know about cleistogamy. Cleistogamy is the self-pollination of some plants that has propagated with the help of non-opening flowers. Peanuts, peas, etc are cleistogamy. Chasmogamy is the opposite of cleistogamy in which the pollination takes place in open flowers. The cleistogamous flowers do not open because of that the pollen from the other flower does not fall on the stigma this results in self-pollination and avoids the cross pollination process, therefore in cleistogamy only autogamy occurs and it ensures autogamy.
Now, the principle advantages of cleistogamy is; it does not require many plants to produce seeds as the large amount of pollen, nectar, and petals development is not required in cleistogamy. This ability makes cleistogamy specifically useful for production of seeds during unfavorable or adverse conditions. For example; Impatiens capensis, this plant produces cleistogamous flowers even after damage severely by the gazing and unfavorable conditions.
The disadvantage of cleistogamy is that it suppresses the formation of genetically superior plants because of the property of self-pollination; it reduces the genetic variation among the plant.

Note: The chasmogamous flowers open after the self-pollination process. Plants like oxalis, peas, hibiscus, beans, etc have chasmogamous flowers. The cleistogamous flowers form assured seed sets when the pollinator is not present as the anther deschise in the flower bud.