Question

Due to which similar character, bird and fishes are in the same phylum? A) Tapering head B) heavy chest C) Caudal fin D) Vertebral column

Answer 1

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.