Question

Distinguish between megasporophyll and microsporophyll.

Answer 1

A sporophyll is a part of the leaf that contains sporangia. Sporophylls are present in both microphylls and megaphylls . In a plant if the sporophyll bears megasporangia, they are called megasporophylls. If it bears microsporangia then it’s called microsporophylls. Sporophylls lead to the development of male and female gametophytes of seed plants (spermatophytes).

Complete answer:
The differences between microsporophyll and megasporophyll is given in the table below.

Microsporophyll	Megasporophyll
They bear microsporangia.	They bear megasporangia.
The microsporangium contains many numbers of microspores or pollen grains.	The megasporangium contains only one functional megaspore.
The microspores of pollen grains are always shed and not retained.	The megaspores are retained inside the megasporangium.
The spores develop into male gametophytes	The spores develop into female gametophytes
The male gametophyte will be formed near the female gametophyte.	The female gametophyte will be produced inside the megasporangium. Fertilisation and embryo formation takes place there.
The microsporophyll is modified into stamen.	In angiosperm, the megasporophyll will be rolled to produce a carpel.

Note:
The sporophylls located near the base of the plant produce spores. Spores are the reproductive part of the plant. Each sporophyll may contain about $10$ billion spores and any plant produces hundred or more sporophylls at least twice a year. Plants generally start producing spores during their first year after attaining $8 - 10{\text{ }}kgs$ of wet somatic mass. The spores are continuously distributed throughout the year, with maxima in early winter and early summer. Some aperiodic events such as increased water motion associated with floods and rain may accelerate the rate of spore release.