What is heterospory? Briefly comment on its significance. Give tw… - Vidyadip

Question

What is heterospory? Briefly comment on its significance. Give two examples.

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Answer

The occurrence of two kinds of spores in the same plant is called as heterospory. Among them the smaller spore is called microspore and the larger spore is called megaspore. Heterospory first evolved in pteridophytes. Significance of heterospory.

Heterospory is associated with the sexual differentiation of gametophyte. A microspore develops into a male gametophyte whereas a megaspore develops into a female gametophyte.
In homosporous pteridophytes spores have to germinate on soil thus face more environmental problems. In heterosporous pteridophytes, spores germinate within the sporangium and the gametophytes are retained inside for variable periods of time. Hence, germinating gametophyte has better chances of survival. This lays the foundation of complete retention of gametophytes within sporophytes in angiosperms and gymnosperms.
Heterospory is the basis of development of seed habit in higher plants.

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