What is megasporangium?

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R :

Assertion A : In gymnosperms the pollen grains are released from the microsporangium and carried by air currents.

Reason R: Air currents carry the pollen grains to the mouth of the archegonia where the male gametes are discharged and pollen tube is not formed.

In the light of the above statements, choose the correct answer from the options given below:

Assertion $\left(\mathrm{A}\right):$ In pteridophytes, the gametophytes require cool, damp, shady places to grow.

Reason $\left(\mathrm{R}\right):$ Specific requirement and the need for water for fertilization, the spread of living pteridophytes is limited and restricted to narrow geographical regions.

The correct answer is:

Pteriodophytes, especially ferns possess the following characteristics

i) Circinate vernation

ii) Ramenta

iii) Eustele

iv) Paraphysis

The correct combination is 

The correct match is:

Choose correct pair from the following
$\mathrm{I})$ Primary producers: Important step in evolution

$\mathrm{II})$ Specific water requirement for fertilization of Pteridophytes: Restricted to narrow geographical regions

$\mathrm{III})$ Growth of young embryo in female gametophyte: Food cycle of aquatic animals

$\mathrm{IV})$ Colonization of mosses and Lichens on rocks: Ecological significance