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Why flowering plants have developed to discourage self pollination and encourage cross pollination |
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Answer» Answer: cross pollintion develops new variety ,and the offsprings are healthier . Explanation: nature preders cross-pollination because of:- (1*)UNISEXUALITY--flowers may be EITHER male or female and they may be born on seperate plant ,thus cross-pollination is tye only method. (2*)DICHOGAMY--in MANY plants tge anthers and stigma matures at different times ...hence couldnot carry out self-pollintion. (3*)SELF-STERILITY--this is a condition where even if the stigma recieves pollens from the anthers of the same flower, it fails to undergo further growthand PERISHES. (4*)HERKOGAMY--(Mechanical or structural barriers)(herkos:barrier) in some flowers the pollens could not reach the stigma of the same flower.example: a hood covering the stigma acts as a machinical barrier in Pansy flowers . (5*)HETEROSTYLY--in such flowers the syigma and antyers grows at different heights which does not favoures self-pollination. hope my answer helps u .... plsss do follow me although i m a beginner |
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