Question

Megasporophyll of Cycas is homologous to
a. Carpel
b. Stamen
c. Petal
d. Sepal

Answer 1

As we all know that the Cycas belongs to Gymnosperms and it is a dioecious plant in which the female cone consists of Megasporophyll leaves which bears the megasporangia (ovules) that basically develops into the female gametophyte called endosperm.

Complete answer:
As we all know that the Gymnosperms are seed producing plants and majorly includes Conifers, cycads, Ginkgo and Gnetales. Cycas is a dioecious plant containing two types of sporophyll- microsporophyll and megasporophyll. Let us look at the difference between them:

Microsporophyll	Megasporophyll
The male cone consists of microsporophyll leaves that bear the microsporangia (spores).	The female cone consists of Megasporophyll leaves which bear the megasporangia (ovules).
They develop into male gametophytes or pollen grains.	They develop into the female gametophytes or endosperm.
They are arranged around the cone axis spirally.	They do not form true cones. However, a couple of whorls are arranged around the apex of the stem.
The pollen grains produced are shed and are not retained.	The megaspore produced is enclosed within the megasporophyll.
This structure is homologous to stamen in angiosperms.	This structure is homologous to carpel in angiosperms.

Hence, the correct answer is option (A).

Additional information:
- The ovules are not at all enclosed inside the ovary but they lie exposed on a leaf like structure called Megasporophyll that possesses stigma, style and ovary.
- In the ovule or megasporangia in nucellus, one megaspore mother cell is present which undergo meiosis and give rise to four haploid linearly arranged megaspores out of which three gets degenerate and one functional megaspore forms the female gametophyte called endosperm.
- The megasporophyll of Cycas forms a closed structure containing ovules and thus is homologous to the carpels as they are also thought to be phylogenetically derived from ovule-bearing leaves.

Note: Cycas possesses the largest male cone, largest male and female gametes. Cycas revoluta species contain the largest ovule and it also produces a starchy food along with sago palm called the Sago. Gymnosperms are also edible like Pinus gerardiana which is commonly called Chilgoza and Taxol, obtained from the bark of Taxus have the anticancer properties.