The locomotory organs of $Echinodermata$ are:

$(a)$ Give a difference between lizards and snakes.
$(b)$ Name the type of nutrition in fungi.

$(a)$ State two characteristic features of nematodes.
$(b)$ Identify the phylum with the help of the following features:
$(i)$ Spiny-skinned,radially symmetrical,and have tube feet.
$(ii)$ Triploblastic,worm-like,having a segmented body.

The system of scientific naming was introduced by

The book 'Systema Naturae' was written by

State the reason for the following:
$(i)$ Nematodes have a pseudocoelom.
$(ii)$ Arthropods have an open circulatory system.
$(iii)$ Echinoderms are named as such.