The stele of $Pteridium$ root is

In $Lycopodium$,the antherozoids are .......

$A$: 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.

How many of the following statements are true about $Azolla$?
$(a)$ It is free-floating.
$(b)$ It has bilobed leaves.
$(c)$ It is nitrogen-fixing.
$(d)$ It is a climber.
$(e)$ It has Aerenchyma in the ventral lobe of the leaf.

$A$ mature ligule,having a prominent basal portion,is called

In the archegonium of a fern,how many neck canal cells are present?