Question

All chordates possess all of the following, at some point in their development, except:

• A. A dorsal hollow nerve cord
• B. A notochord
• C. Gill slits
• D. Post-anal tail
• E. An exoskeleton

Answer 1

The correct option is E An exoskeleton

The characteristic features of chordates include the presence of:

1) A notochord

2) Pharyngeal gill slits

3) A post-anal tail

4) A dorsal hollow nerve cord

The presence of the exoskeleton is not a characteristic feature of chordates. An exoskeleton might be present in some animals in the form of hair, scales, feathers, etc. It protects an animal's body. Endoskeleton is derived from the notochord and can be bony or cartilaginous. Some chordates may have both exoskeleton and endoskeleton and some might have an endoskeleton only.

Therefore, the correct answer is option E.