Question

Chordates are distinguished from non-chordates by the presence of

• A. closed circulatory system
• B. a ventral tubular nerve cord
• C. cold or warm blooded
• D. post-anal tail

Answer 1

The correct option is D post-anal tail

All the chordates have a post-anal tail at some point in their life. Non-chordates lack tail.
Chordates have dorsal tubular nerve cord. Dorsal refers to the backside of the organism and ventral refers to the front or the abdominal side of the organism. Chordates are cold or warm blooded animals but most of the non-chordates are cold blooded.
All chordates have a closed circulatory system.
Some non-chordates like annelids also have a closed circulatory system.