Crocodile and penguin are similar to whale and dogfish in which one of the following features

Options

(a) Possess a solid single stranded central nervous system
(b) Lay eggs and guard them till they hatch
(c) Possess bony skeleton
(d) Have gill slits at some stage.

Correct Answer:

Have gill slits at some stage.

Explanation:

Animals belonging to phylum chordata are fundamentally characterised by the persence of a notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. Crocodile, penguin, whale and dogfish are all chordates. All of them have gill slits or have had it during embryonic development. Thus, paired gill slits are present in these animal at some stage of life.