Chasmogamy refers to the pollination of chasmogamous flowers. Flowers with exposed anthers and stigma are referred to as chasmogamous flowers. Most chasmogamous flowers are cross-pollinated by various pollinating agents such as wind, bees, insects, etc.
Chasmogamous flowers open to expose their reproductive parts (anther, stigma), thus allowing cross-pollination. Chasmogamous flowers are the opposite of cleistogamous flowers, which do not open at all. Cleistogamous flowers exclusively show self-fertilisation or autogamy.
Cross-pollination in chasmogamous flowers is beneficial as it leads to more genetic variability and reduces inbreeding depression. Cross-fertilisation produces more genetic diversity in seeds. Seeds produced by cross-fertilisation in chasmogamous flowers show increased fitness and hybrid vigour.
Chasmogamous flowers have attractive petals or nectaries to attract and reward pollinating agents and to promote cross-pollination. It is beneficial but there is a dependency on pollinating agents unlike cleistogamous flowers, which do not depend on pollinating agents for pollination and produce an assured seed-set.
Some plants produce both chasmogamous and cleistogamous flowers, e.g. Commelina, Viola, Oxalis, etc. The presence of both types of flowers allows both self-fertilisation and cross-fertilisation. It ensures genetic diversity along with the production of seeds in variable environments and less dependency on pollinators.
This was in brief about Chasmogamy. Learn more about other related concepts for NEET, only at BYJU’S.
Sexual Reproduction in Flowering Plants | Top 10 Questions