Seed habit originated firstly in some

In the prothallus of $Dryopteris$ (fern),the sex organs are located on the:

The stele of $Pteridium$ root is

In $Selaginella$,when the sporophyte develops directly from the female gametophyte other than the oosphere,the condition is called:

$A$ fern prothallus is bisexual. If fertilization takes place between the gametes produced by the same prothallus,then it is known as:

Compared to the gametophyte of bryophytes,the gametophyte of vascular plants (pteridophytes) has ......