Question

Which among the following is not a characteristic of all chordates?

• A. Presence of coelom
• B. Pharyngeal gill clefts in early embryonic stages
• C. Diaphragm separating thorax from abdomen
• D. Dorsal nerve cord

Answer 1

Answer: (C)

Diaphragm separating thorax from abdomen

• The diaphragm separating the thorax from the abdomen is only present in mammals and it is a character exclusive to them.
• The presence of coelom, pharyngeal gill cleft (in early embryonic stages) and a dorsal nerve chord are all general characteristics of all chordates.

So the correct answer is option C.