What are three main characteristics of birds and mammals and reptiles all have in common?

Answer 1

1. Birds have no diaphragm so the abdomen communicates directly with the thorax, this includes the lungs, heart and air sac.

2. Birds have the ability to fly. This is a great advantage when escaping form predators

3. Mammals have the ability to be coordinated on the ground, are able to move easier.

Answer 2

1. Reptiles are cold-blooded, while mammals and birds are warm-blooded.

2. Reptiles are covered in scales, while birds are covered in feathers, while mammals have at least some fur.

3. All birds lay eggs. Almost all mammals give live birth, but the monotreme mammals lay eggs. Most reptiles lay eggs, but some give live birth, and some have eggs that hatch inside the mother just before being laid (ovoviviparity).

Answer 3

1. All are amniotes.

2. All breathe only oxygen.

3. All have dead cells forming the outer layer of skin in order to retain water.

There are more common characteristics than these three.