Identify the Pteridophytes based on their spores.
Homosporous $\quad$ Heterosporous

$A$ - Selaginella and Salvinia produce heterospores.
$R$ - Cones (strobili) are developed in Selaginella and Equisetum.

While entering the neck of a fern archegonium,sperms show:

Read carefully the following statements about sexual reproduction in ferns:
$I.$ Water is essential for fertilization.
$II.$ The male gametophyte bears antheridia,while the female gametophyte bears archegonia,which produce antherozoids and egg cells,respectively.
$III.$ Antherozoids and egg cells fuse to give rise to a zygote. The zygote develops into a young embryo. The embryo gives rise to a sporophyte.
Which of the statements given above are correct?

Microspore and megaspore are found in $-$

Pteridophytes differ from bryophytes in the presence of ........