Question

Why was heterospory important? What two other strucutres evolved as a result of the origin of heterospory?

Answer 1

Importance of heterospory:-

• It leads to the formation of seed habitat. In heterosporous plants the chance of self- fertilisation is reduced as male and female gametangia are separated both in space and time. This result in increase in chance of variability in progenies.
• Heterospory produced endosporic gametophyte which are independent of external harsh environmental conditions.
• The heterosporous form, facilitated sex differentiation at spore stages.
• Heterospory reduced the size of gametophytic generation.

Heterospory refers to the phenomenon in which plants produces two kinds of spore that differ in size. These two types of spore producing structures are:-

• Microsporangia- produces microspores that develops into male gametophyte and produce sperm.
• Megasporangia-produces megaspores that develops into female gametophyte and produce egg.