Which of the following is a characteristic of both mammals and birds?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Warm-blooded.
A characteristic of both mammals and birds is that they are warm-blooded. This means both mammals and birds are endothermic, maintaining a constant body temperature regardless of the external environment. This is in contrast to cold-blooded animals, which rely on external heat sources to regulate their body temperature. While mammals and birds differ in other characteristics (like viviparity in most mammals and egg-laying in many birds), warm-bloodedness is a shared trait that helps them adapt to various environments.