Skip to content
Biology journal Cambridge IGCSE 0610

Pupil sheet · Diffusion and active transport

Active transport — questions

Name ______________________ Date ____________

Try every question before you use a nudge. Write in full sentences where you are asked to explain.

1. define

Which statement describes active transport?

Circle one answer.

  • Net movement of particles from higher to lower concentration
  • Movement of water through a membrane
  • Movement of particles down a gradient using energy
  • Movement of particles through a membrane from lower to higher concentration, using energy from respiration

Nudge (only if you are stuck): Which way does it move particles compared with diffusion, and what does it need?

2. compare

Sort each statement: true of diffusion, true of active transport, or true of both.

Write the number of the matching option.

  1. Diffusion
  2. Active transport
  3. Both
  • Needs energy from respiration: ______
  • Moves particles down a concentration gradient: ______
  • Moves particles through the cell membrane: ______
  • Needs carrier proteins: ______

Nudge (only if you are stuck): Which one needs energy from respiration? Which one goes against the gradient?

3. explain

The concentration of nitrate ions is higher inside root hair cells than in the soil water around them. Explain how and why the root hair cells take in more nitrate ions.

Nudge (only if you are stuck): Diffusion would move the ions which way? What does the cell use instead?

4. describe

Put the steps of active transport by a carrier protein in order.

Write the number of each step in order.

  1. The ion is released inside the cell
  2. The ion binds to the carrier on the outside
  3. The carrier returns to its first shape
  4. The carrier changes shape using energy from respiration
  • First: ______
  • Second: ______
  • Third: ______
  • Last: ______

Nudge (only if you are stuck): The ion must bind before the carrier changes shape.

5. suggest / explain

A scientist adds a poison that stops respiration to the water around some root hair cells. Predict what happens to (a) the uptake of nitrate ions and (b) the uptake of oxygen by diffusion. Explain each prediction.

(a) Nitrate ions

(b) Oxygen

Nudge (only if you are stuck): Which process needs energy from respiration, and which uses only the kinetic energy of the particles?