Question

In Cycas,
A. Ovule and microsporangia are present in the same sporophyll
B. Micro and megasporophyll are present in the same cone
C. Male cone and megasporophyll are borne on the same plant
D. Male cone and megasporophylls are borne on separate individual plants

Answer 1

Hint: Plants have various parts- both male and female. They can be present on different individuals or the same plant. Based on their presence, they can be monoecious and dioecious. The different sporophytes give germ cells to fertilize.

Complete answer:
Cycas is a dioecious plant. Dioecious means having different male and female sporophytes. The male sporophyte will have minute microsporangia in the adaxial surface of the microsporophyll. The female cone will have loosely arranged megasporophylls. These megasporophylls will have ovules.

> Option A: Ovule and microsporangia are present in the same sporophyll: ovule belong to female sporophyte and microsporangia belong to male sporophyte so they cannot be in the same sporophyll as cycas is dioecious.

> Option B: Micro and megasporophyll are present in the same cone: Microsporophyll is male sporophyll while the megasporophyll is the female one, they are both different in the cycas.

> Option C: Male cone and megasporophyll are borne on the same plant: The microsporophyll and megasporophyll occur on different individual plants.

> Option D: Male cone and megasporophylls are borne on separate individual plants: male cone having microsporangia and megasporocyte being the female sporophyte, both are present on different individual plants as Cycas is dioecious.

Hence, the correct answer is option (D).

Note: Cycas belong to Cycads group. They are long trees which become 6-20 metre long at maturity. They have an unbranched thick stem. They have large terminal leaves. Cycas’s age can be estimated by the number of whorls on leaf scar. They are like palm trees.