Question

Which one is the distinguishing feature of all vertebrates?

• A. An internal bony or cartilaginous skeleton
• B. A hairy body covering
• C. Presence of mammary glands
• D. Open type of circulatory system

Answer 1

Answer: (A)

An internal bony or cartilaginous skeleton

The vertebrates comprise a large group of chordates and are sub-divided into seven classes (3 classes of fish, amphibians, reptiles, birds and mammals).

All vertebrates have an internal skeleton of cartilage or bone, with vertebrae surrounding the dorsal nerve cord.
A hairy body covering, the presence of mammary glands are the characteristic of mammals. The vertebrates have a closed circulatory system.

So, the correct answer is option A.