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

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 talls.
Fish and reptiles develop scales. Amphibians, birds, and humans have skin. Birds have feathers, and humans have hair.
With which animal do humans exhibit the most linear relationship? (1 point)
O fish
O birds
• reptiles
O amphibians

The answer is reptiles. Humans and reptiles both develop scales in their embryos, which is a linear relationship.