Different animals, different canals

The idea

Animals show variations in the structure and function of the alimentary canal, adapted to digesting different kinds of food.

One plan or many?

A cow eats grass, a hen eats grain, and you eat chapati.

Do all animals digest food in exactly the same way?

• No, the canals differ to suit different foods
• Yes, in exactly the same way
• Only birds are different

Compare

Tap Human, Cow and Bird. Look at what changes.

Built for the food

The cow brings food back to chew it again. The bird has a gizzard and no teeth. The structures and jobs differ to suit the food.

Animals show variations in the structure and function of the alimentary canal, adapted to digesting different kinds of food.

Notes

Animals show variations in the structure and function of the alimentary canal, adapted to digesting different kinds of food.

Check yourself

Which animal brings food back from the stomach to the mouth for more chewing?

Which animal breaks its food with a gizzard?

Why do the alimentary canals of animals differ?

A bird has no teeth. Which statement is right?

• The bird. A bird has no teeth. It breaks food in its gizzard.
• The human. Humans do not bring food back from the stomach to chew it again.
• The cow — correct. Yes!
• The bird — correct. Yes!
• The cow. A cow chews and ruminates. The gizzard is found in birds.
• The human. Humans chew with teeth. The gizzard is found in birds.
• Because the animals have different colours. Colour does not decide the canal. Adaptation to different kinds of food does.
• They are adapted to digest different kinds of food — correct. Yes!
• Because the animals sleep for different times. Sleep does not decide the canal. Adaptation to different kinds of food does.
• It cannot break food at all. A bird breaks food in the gizzard.
• It has teeth inside the gizzard. Birds have no teeth. The walls of the gizzard break the food.
• It breaks food with its gizzard — correct. Yes!