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Q.
When pollen grains are not transferred from anthers to stigma in a flower, due to the barrier, it is called
Sexual Reproduction in Flowering Plants
Solution:
When some physical barrier is present between male and female reproductive parts of a flower which prevents self pollination, it is called herkogamy. Some flowers, do not expose their sex organs. Such flowers are called cleistogamous and the phenomenon as cleistogamy. Here self pollination takes place. Dichogamy refers to maturation of male and female sex organs at different times. Heterogamy term is used for cross - pollination.