Q. Which one of the following in birds, indicates their reptilian ancestry?
A) Eggs with a calcareous shell
B) Scales on their hind limbs
C) Four-chambered heart
D) Two special chambers crop and gizzard in their digestive tract
Explanation
[Solution from source] NCERT notes that the hind limbs of birds generally bear scales, a retained reptilian character. A four-chambered heart is a feature birds share with mammals rather than with reptiles (which mostly have three chambers), so it does not indicate reptilian ancestry. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.