The three outbreeding devices that flowering plants have developed, so as to encourage cross-pollination are: (i)Receptivity of stigma and release of pollen grain is not synchronised, i.e. stigma becomes receptive much before pollens are released or after they are released to avoid self-pollination. (ii) Self-incompatibility, a genetic mechanism to prevent pollens from fertilising ovules of same flower by inhibiting their germination on stigma or pistil. (iii) Production of unisexual flowers so that male and female parts will be present on different plants (dioecious) or on different flowers in same plant (monoecious). It prevents both autogamy and geitonogamy.
Make a list of any three outbreeding devices that flowering plants have developed and explain how they help to encourage cross pollination.
Answers
Rajendra
The three outbreeding devices that flowering plants have developed, so as to encourage cross-pollination are:
(i)Receptivity of stigma and release of pollen grain is not synchronised, i.e. stigma becomes receptive much before pollens are released or after they are released to avoid self-pollination.
(ii) Self-incompatibility, a genetic mechanism to prevent pollens from fertilising ovules of same flower by inhibiting their germination on stigma or pistil.
(iii) Production of unisexual flowers so that male and female parts will be present on different plants (dioecious) or on different flowers in same plant (monoecious). It prevents both autogamy and geitonogamy.