Page 29 - Exercise 1

Page 29 - Exercise 1

There are five different type of animals with back bones (vertebrates).

1) Mammals

Mammals are warm-blooded. They control the temperature of their body. They usually have hair of fur on their bodies and they produce milk for their babies. Horses, tigers, squirrels and mice are all mammals. We’re mammals, too.

2) Reptiles

Reptiles are cold-blooded. They can’t control the temperature of their body, so they don’t normally live in very cold parts of the world. Snakes, lizards and crocodiles are all reptiles. Reptiles don’t produce milk. They lay eggs. They must lay their eggs on land. Some reptiles, like turtles, live in water, but they must come onto land to lay their eggs.

3) Birds

Birds lay eggs, too, but they aren’t cold-blooded. Birds have got feathers to keep them warm. Feathers also help birds to fly. Not all birds can fly. Some birds are too big and heavy, but they can usually run very fast instead. Penguins are birds, too. They can’t fly, but they are good swimmers. The only other vertebrates that can fly are bats. They aren’t birds. Thy’re mammals.

4) Fish

Fish are cold-blooded and they lay eggs. Some fish, like sharks, live in the sea. Other fish, like carp, live in lakes and rivers. Fish are the only vertebrates that don’t breathe air. Whales and dolphins live in the sea, too, but they aren’t fish. They’re mammals. They produce milk and they breathe air.

5) Amphibians

These animals can live in fresh (not sea) water and on land. They are cold-blooded and lay eggs, like reptiles, but they can’t live all the time on land, and they must lay their eggs in water. Frogs are amphibians.