What is heterospory? Briefly comment on its significance. Give two examples
Explanation The occurrence of two different types of spore in same plant is called heterospory.. These spores generally differ in size. The spore which is smaller in size is referred to as microspore whereas spore which is larger in size is defined as megaspore. Microspore develops into a male gametophyte, megaspore develops into the female gametophyte. The male gametophyte produces male gamete which fuses with female gamete produced by female gametophyte giving rise to a zygote. The proper development of zygote is ensured by the retention and germination of megaspore within the sporangium. The zygote matures into the sporophyte. The evolution of seed habit is generally related to the retention of megaspore. Heterospory is considered as an important step in evolution. Heterospory was first seen in pteridophytes and is thought to be the precursor of seed habit in plants. Example Heterospory is seen inSelaginella, Salvinia Final Answer The occurrence of two different spores within a plant is called heterospory. This phenomenon leads to the development of seeds in gymnosperm and angiosperm.It is generally needed for the differentiation of male and female gametophyte. Heterospory is considered as an important step in evolution. Heterospory was first seen in pteridophytes and is thought to be the precursor of seed habit in plants. Some examples of pteridophytes that exhibit heterospory is Selaginella andSalvinia.
