Crocodile and penguin are similar to whale and dogfish in which one of the following features?

Which one of the following figures shows radial symmetry?

Match the following columns correctly and select the appropriate option:

Column $A$	Column $B$	Column $C$
$(1)$ Planaria	$(a)$ Planula	$(e)$ Ostia
$(2)$ Hyalonema	$(b)$ Pseudocoelomate	$(f)$ Flame cells
$(3)$ Hydra	$(c)$ Platyhelminthes	$(g)$ Polyp
$(4)$ Wuchereria	$(d)$ Porifera	$(h)$ Aschelminthes

Solenocytes and nephridia are respectively found in

Give the correct match in the following:

Column-$I$	Column-$II$
$(A)$ Flame Cells	$(p)$ Sponges
$(B)$ Collar Cells	$(q)$ Hydra
$(C)$ Stinging cells	$(r)$ Planaria
	$(s)$ Ascaris

Give an example of the following:
$(a)$ $A$ viviparous animal
$(b)$ $A$ fish possessing a poison sting
$(c)$ $A$ fish possessing an electric organ
$(d)$ An organ which regulates buoyancy
$(e)$ An animal which exhibits alternation of generation
$(f)$ An oviparous animal with mammary glands