Question

1. What specific features make the exchange of gases in gills and lungs possible?
2. Capillaries are things walled. Why?
3. Arteries are thick walled. Why?
4.why is small intestine very long in our body?

Answer 1

1. higher concentration of carbon dioxide in gills and lungs makes it possible for exchange of gases.
2. capillaries are thin-walled because they are also to deal with gaseous exchange inside the body cells so if they wear thick the gaseous exchange wouldn't be very easy.
3. arteries are thick walled because they get blood directly from heart by pumping so if they were thin they would brust out.
4. as main work of small intestine is to absorb the nutrients of the food so if it is small then it would not absorb much of the nutrients from the food so it is very long in our body.