Fish, amphibians, reptiles, birds, and mammals have similar embryos.

Question

They all start with gill slits. Fish and some amphibians grow to have gills. Some amphibians, reptiles, birds, and mammals develop lungs to breathe air.
They all start with tails. Fish, some amphibians, reptiles, and birds grow tails. Humans do not keep their tails.
Fish and reptiles develop scales. Amphibians, birds, and humans have skin. Birds have feathers, and humans have hair.

Which two animals exhibit the most linear relationship?(1 point)
Responses

birds and humans
birds and humans

birds and reptiles
birds and reptiles

amphibians and reptiles
amphibians and reptiles

amphibians and fish

Answer 1

To determine which two animals exhibit the most linear relationship based on the information about embryonic development and physical characteristics, we can analyze the provided options:

1. Birds and Humans: Both have lungs, feathers (for birds), and hair (for humans). However, they are from very different evolutionary backgrounds, which makes their relationship less linear.

2. Birds and Reptiles: Birds are considered to be a type of theropod reptile, sharing many characteristics, including scales (initially) and eggs. Their evolutionary relationship is more direct and linear compared to the other pairs.

3. Amphibians and Reptiles: Both groups develop lungs and share common features, but they diverged earlier on in evolutionary history.

4. Amphibians and Fish: While they share some characteristics like gill slits, they are fundamentally different categories of animals with a significant evolutionary gap.

Considering these analyses, birds and reptiles exhibit the most linear relationship due to their close evolutionary connection and shared characteristics. Therefore, the correct answer is:

birds and reptiles