In $Selaginella$,the adaxial outgrowth,from the base of the leaf,is called:

Which of the following is not heterosporous?

Which one of the following is a correct statement?

The antherozoids of $Selaginella$ have:

The new leaf of ferns is called:

$A$: Seeds are formed by some species of spike moss.
$R$: All conditions for seed habit are fulfilled by these species of spike moss.