Q. Which of the following groups of animals is correctly matched with its one characteristic feature without even a single exception?
A) Mammalia : give birth to young ones
B) Reptilia : possess 3-chambered heart with one incompletely divided ventricle
C) Chordata : possess a mouth provided with an upper and a lower jaw
D) Chondrichthyes : possess cartilaginous endoskeleton
Explanation
[Solution from source] Every member of Chondrichthyes (sharks, rays) has a cartilaginous endoskeleton, with no exceptions. Not all mammals give birth (platypus lays eggs), crocodiles have a four-chambered heart, and jawless cyclostomes are chordates without jaws. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.