Question

do you think cleistogamy is advantageous or disadvantageous to the plant?why?

Answer 1

cleistogamy is a disadvantage to a plant because due to repetitive self pollination chances of evolution decreases

Answer 2

Cleistogamy is the self pollination occurring in an unopened flower.Self-pollination in this case is the transfer of pollen grains from anther to the stigma of the same flower which is unopened.
 
Advantages:
* This type self-pollination does not require external agent.
* It preserves useful characters of the parent individual.
* It helps in producing pure lines.  

Disadvantages:
*This self-pollination does not help in producing new varieties and species.

(^_^)