Give one example of hemichordata, urochordata and cephalochordata.

Define phylogeny.

Identify animal groups having

(a) Soft bodied animals supported by calcareous shells;

(b) Spiny body has radial body symmetry;

(c) Bones light and hollow;

(d) Four pairs of jointed legs and no wings;

(e) Extemal ear or pinna.

Give one point of difference between notochord and nerve cord.

In what way, amphibians are advanced than the fishes?