Exchanging Materials

Question 1

What is exchanging materials

Answer 1

This exchange takes place by diffusion and active transport. Villi are adapted for the maximum absorption of digested food molecules because: the folded villi greatly increase the surface area of the intestine. the villi are made of a single layer of thin cells.

Question 2

Getting bigger

Answer 2

For larger, more complex organisms – which have a small surface area:volume ratio and a bigger distance from the surface to the cells inside the body - diffusion alone is insufficient to meet the needs of all cells.

Question 3

Adaptations

Answer 3

Villi are adapted for the maximum absorption of digested food molecules because: the folded villi greatly increase the surface area of the intestine. the villi are made of a single layer of thin cells. beneath the villi is an extensive blood capillary network to distribute the absorbed food molecules.