State one difference and one similarity between geitonogamy and xenogamy.

Question

(a) State one difference and one similarity between geitonogamy and xenogamy.
(b) Explain any three devices developed in flowering plants to discourage self pollination and encourage cross pollination.

Answer 1

(a) Difference- In geitonogamy pollen grains from one flower are transferred to the stigma of another flower on the same plant whereas in xenogamy the pollen grains are transferred to the stigma of a flower on another plant(of the same species) genetically similar , genetically different Similarity -In both types of pollination pollen grains from the anther are transferred to the stigma of another flower of the same species
(b) - Pollen release & stigma receptivity not synchronised / hence the maturity of stigma and pollen are different /Protandry / Protogyny
- Anther and Stigma are placed at different positions so that pollen cannot come in contact with stigma of the same flower.
- Self incompatibility/ Self sterility.
- Production of unisexual flowers