Practice Question

1.Name 3 factors that affect the rate of diffusion

1.The difference in concentrations (concentration gradient)

2.Temperature

3.The surface area of the membrane.

2. A perfume is sprayed into the corner of a room. A person at the other end of the room detects the smell faster in June, than they do in December. Explain why.

Diffusion is the spreading out of particles from an area of high concentration to an area of low concentration.

The perfume particles spread through the air in the room by diffusion.

In June, the room is warmer than in December.

At a higher temperature, the air particles and the perfume particles have more kinetic energy.

This makes them move faster and collide more often, so diffusion happens more quickly.

Therefore, the person detects the smell sooner in June than in December.

3. Below is an image of a root hair cell.