Diffusion (B3.1)

Question 1

Diffusion definition

Answer 1

Diffusion is the net movement of particles from a region where their concentration is higher to a region where their concentration is lower, down a concentration gradient, as a result of their random movement

Question 2

Net movement definition

Answer 2

When more particles overall move down the concentration gradient in liquids and gases

Question 3

Diffusion in organisms examples (3)

Answer 3

• movement of Co2 amd O2 in leaves
• movement of glucose (diffuses through intestinal wall) and other food molecules in and out of the blood
• movement of Co2 and O2 in the alveoli of the lungs

Question 4

Factors of diffusion (4)

Answer 4

Passive process - rate increase if:
- temp. increases
- distance decreases
- surface area increases
- concentration gradient increases