Fill in the boxes given in the figure with appropriate characteristics or plant groups.

$(a)$ 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 endoskeleton of fishes is made up of cartilage or bone. Classify the following fishes as cartilaginous or bony: Torpedo,Sting ray,Dog fish,Rohu,Angler fish,Exocoetus.

Give the points of differences between non-chordates and chordates.

Classify the phylum Vertebrata into their further groups by giving two characteristics of each.

State reasons for the following:
$(a)$ Mammals have mammary glands.
$(b)$ Annelids have a true body cavity.
$(c)$ Fish possess gills.