Selaginella possesses an outgrowth proximally on the adaxial surface of its leaves. What is this structure called?

Select the correct option for the following statements:
$(i)$ In $Dryopteris$ (fern), the prothallus is $haploid/diploid$.
$(ii)$ In $Pteridophytes$, there are $rhizoids/roots$.

$Selaginella$ is characterized by the presence of:

$Pteridium$ possesses:

In aquatic ferns,the sporangia are found in a specialized structure called a sporocarp. This aquatic fern is .......

$Selaginella$ and $Salvinia$ are considered to represent a significant step toward the evolution of seed habit because