While the majority of flowers are perfect or hermaphrodite (having both pollen and ovule producing parts in the same flower structure), flowering plants have developed numerous morphological and physiological mechanisms to reduce or prevent self-fertilization. Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal pollinators cannot easily transfer pollen to the pistil (receptive part of the carpel). Homomorphic flowers may employ a biochemical (physiological) mechanism called self-incompatibility to discriminate between self and non-self pollen grains. In other species, the male and female parts are morphologically separated, developing on different flowers. COUNT 5
QSN1 What sexual feature do a majority of flowers demonstrate? ANS1 hermaphrodite QSN2 Why did flowering plants develop numerous morphological and physiological mechanisms? ANS2 reduce or prevent self-fertilization QSN3 Why are a heteromorphic flower's carpels and stamens different lengths? ANS3 so animal pollinators cannot easily transfer pollen to the pistil QSN4 What type of mechanism might homomorphic flowers use to tell the difference between foreign and self pollen grains? ANS4 biochemical QSN5 How are some male and female parts separated for some species? ANS5 different flowers