Lungs, gills and moist skin

A fish breathes with gills. What do gills take in?

The idea

Gills take in the oxygen dissolved in water. Dissolved means mixed all through the water. Birds, lizards, snakes and cows breathe with lungs. An earthworm breathes through its moist skin. Moist means slightly wet.

Take a frog. In water, its skin takes in oxygen. On land, it uses its lungs. Its tadpole breathes with gills. A part that takes in oxygen is a breathing surface.

Fish use gills. Earthworms use moist skin. Lizards use lungs. A frog uses more than one surface.

Try the lab to finish this lesson.