Small Intestines And Lungs

Question 1

Explain how the vili and the alveoli are adapted to absorb molecules into bloodstream. (6marks)

Answer 1

Both of them have a large surface area.
- villi have mang microvili
- alveoli have many folds
These adaptations maximise (enhance) diffusion (alveoli) and absorption of food molecules

They both also have thin walls which helps to provide a short diffusion distance + for food molecules to travel

Villi have many mitochondria
To provide energy for active transport