Question

Crocodile and penguin are similar to whale and dogfish in which of the following feature?

• A. They possess a solid single stranded central nervous system.
• B. They lay eggs and guard them till they hatch.
• C. They possess bony skeleton.
• D. They have gill slits at some stage.

Answer 1

Answer: (D)

They have gill slits at some stage.

Chordates are the animals that possess a notochord, a dorsal nerve cord, and pharyngeal gill slits at some stage of their lives. They are further classified into classes like Mammalia, Aves, Reptilia, Amphibia, and Pisces. The animals given in the question belong to one class or the other among these and all are hence chordates.

So, the correct answer is 'They have gill slits at some stage'.