The stele in the rachis of $Pteris$ is

In $Selaginella$,the embryo develops into:

In $Dryopteris$ (fern),the permanent roots are .........

Disposal of spores in ferns takes place through

$A$: Events precursor to the seed habit are seen in some members of pteridophytes.
$R$: Development of the zygotes into young embryos takes place within the female gametophyte.

Pteridophytes that produce strobili (cones) are .....