biology B3

Question 1

Explain the difference between diffusion and osmosis?

Answer 1

diffusion is the movement of particles from high concentration to a low concentration. Whereas osmosis is the movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration.

Question 2

Explain why active transport requires energy, whereas diffusion and osmosis.

Answer 2

because the particles have to be moved across a concentration gradient from low to high.

Question 3

describe 2 adaptations of the villi which help the small intestine to function.

Answer 3

1) Increase surface area so a more food can be absorbed.

2) very good blood supply to aid absorption.