Heterospory is a development towards seed habit Do you agree?

1.	Heterospory is a development towards seed habit Do you agree?
Answer» 1.Yes Production of two types of spores by a plant is called heterospory. Eg : Selaginella. 2.Large spores are called megaspores and small spores are called microspores. Megaspore → Female gametophyte →Archegonia →egg. Microspore →Male gemetophyte →Antheridia →Antherozoids. 3.The two gametophytes remain protected inside the respective spores in the sporophytic phase. Microspores are dispersed by wind and reach the Megaspore. The Antherozoid fuses with the egg toform zygote. Thus the gametophytic generation is completed in the sporophyte plant itself. Only a er zygoteformation the female gametophyte is shed from the sporophyte. This is a basic requisite for seed habit. Distinguish apogamy and apospory. 1.Apogamy - A type of reproduction occuring in some ferns in which the sporophyte develops from the gametophyte without fusion of gametes. 2.Apospory - The development of a gametophyte directly from a sporophyte without the occurrence of mieosis or spore formation. Both apogamy and apospory are seen in pteridophytes. Why do mosses thrive only in moist habitat? Mosses (bryophytes) are non-vascular land plants of moist habitat that grow densely together ando en form green carpets or mats on damp soil. It is because in the absence of roots, thallus absorbs water and minerals directly from ground oratmosphere. Hence, they can thrive only on moist places.

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