Question

Due to which similar character birds and fishes are of the same phylum
A- tapering head
B- heavy head
C- caudal fin
D- maintain balance

Answer 1

I think the answer is D)maintain balance.

Answer 2

The phylum chordates includes both fish and bird.

The main characteristics of this phylum are; 1) Presence of notochord, 2) Presence of dorsal hollow nerve chord, 3) Presence of pharyngeal slits, 4) Presence of post anal tails.

Now here comparing the options given, Caudal fin is the nearest to the option 4 mentioned above which is presence of post anal tail. Now caudal fin specific characteristic of fishes. It is the outgrowth after the post anal tail of a fish. Birds don't have caudal fin exactly though analogous growth can be noticed. So, this can be the correct option.