The stele found in ferns is known as:

The sorus of $Dryopteris$ fern is:

Ligulate leaves are found in

The antherozoids of $Selaginella$ have:

The evolutionary advanced features of $Selaginella$ are:
$(a)$ Heterospory
$(b)$ Endosporic development of gametophyte
$(c)$ Reduced gametophyte
$(d)$ Localization of sporangium-bearing appendages in strobili
$(e)$ Unisexual gametophytes
$(f)$ Fertilization with the help of water

In Pteridophyta and gymnosperms,which cells are present in place of companion cells?