Define Geitonogamy.

Hint: The word geitonogamy represents a type of pollination in plants which results in reproduction. Geitonogamy is a type of pollination specifically self – pollination. In addition to it, it is a form of self – fertilization.

Complete step by step answer: Geitonogamy can be defined as a type of self-pollination in which pollination of plants takes place by transfer of pollen from one flower to the stigma of another flower of the same plant via wind or pollinator. Geitonogamy occurs in species that are wind pollinated and it may be quite a common source of self-fertilized seeds with the species that are self-compatible. Also, in monoecious gymnosperm geitonogamy type of self-pollination is observed. Maize is an example of monoecious plants that exhibit geitonogamy type of pollination. Self-fertilization is also called autogamy. In autogamy fusion of two gametes takes place that comes from one single individual. The advantages of self-pollination are that it is a sure method of pollination that does not depend on external factors. It involves the least wastage of pollen grains and genetic stability is maintained. By geitonogamy, the pure line plants can be preserved. The original characteristics of plants can be preserved and can be used to multiply the improved varieties of plants. There are also many disadvantages of geitonogamy. The geitonogamous plants do not adapt to the new environmental changes thus leading to reduced health of species.

Note: Geitonogamy is functionally cross-pollination which involves a pollinating agent. Geitonogamy is similar to autogamy as the pollination takes place within the same plant. In dioecious plants like Cucurbita maxima geitonogamy is not possible.