The antherozoid of $Selaginella$ has:

Independent alternation of generations is found in .......

Plants with small leaves (microphylls) are included in which of the following classes?

$Selaginella$ is heterosporous. It produces two types of spores. The microspore develops into microgametophyte and the megaspore develops into megagametophyte. With respect to gametophyte,which one statement is correct?

Give detailed information about pteridophytes.

In $Dryopteris$,the sori are borne: