Question

A dioecious flowering plant prevents both

• A. autogamy and geitonogamy
• B. autogamy and xenogamy
• C. geitonogamy and xenogamy
• D. none of the above

Answer 1

The correct option is A autogamy and geitonogamy

A dioecious plant has male and female reproductive structures on separate plants.

Hence a dioecious flowering plant has either male or female flowers but not both.

The pollen grains from the male plant are transferred to the stigma of the female plant. This type of pollination is called xenogamy, in which flowers of two different plants are involved.

Autogamy (transfer of pollen grains to the stigma of the same flower) and geitonogamy (transfer of pollen grains to the stigma of another flower of the same plant) are not possible in dioecious plants.

Hence it prevents both autogamy and geitonogamy.