Sixth Grade
Worksheets
Animals With Backbones
Feel the back of your neck. The bones at the back of your neck are connected to small bones all the way down the middle of your back. These bones make up your backbone. Scientists put all animals into two large groups. One group is animals with backbones. The other group is animals without backbones.
Animals with backbones are called vertebrates. Each bone in the backbone is called a vertebra. As the animal grows, its backbone grows, too. An animal with a backbone can usually grow larger than an animal without a backbone. Animals with backbones often have bigger brains, too.
Some animals with backbones spend part of their lives living in water and part of their lives living on land. These animals are called amphibians. When they live in water, they use gills to breathe. When they live on land, they use lungs to breathe. A tadpole begins its life in water. Then, when it becomes a frog, it lives on land.
