O Level / IGCSE Biology chapter 3: Movement into and out of cells MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
21 exam-style questions on Movement into and out of cells, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Ten Movement into and out of cells questions with answers
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. What is needed for active transport but not for diffusion?
A
energy from respiration
B
a concentration gradient
C
a partially permeable membrane
D
a high temperature
Show answer
Answer: A. Active transport uses energy released by respiration. Diffusion relies only on the random movement of particles.
2. Root hair cells absorb nitrate ions from soil water where the nitrate concentration is lower than inside the cells. Which process is used?
A
transpiration through the stomata
B
osmosis through a partially permeable membrane
C
diffusion down a concentration gradient
D
active transport
Show answer
Answer: D. The nitrate concentration is lower in the soil than in the cell, so the ions must be moved against the gradient, which needs active transport using energy from respiration.
3. The concentration of potassium ions inside a root cell is twenty times that in the soil water, yet potassium ions continue to enter the cell. Which conclusion is correct?
A
potassium enters by active transport against its concentration gradient
B
potassium enters by diffusion down its concentration gradient into the cell
C
potassium enters by osmosis, moving in with the water that enters the root cell
D
the cell must be losing potassium by diffusion at the same rate as it gains it
Show answer
Answer: A. Potassium is moving into a region where it is already more concentrated, which is against the gradient. Only active transport can do this.
4. Red blood cells are placed in distilled water. What happens to them?
A
they shrink, because water leaves them by osmosis and they have no wall to support them
B
they become turgid and keep their shape, because their cell walls resist the water
C
they become plasmolysed, because water leaves them by osmosis
D
they burst, because water enters and there is no cell wall
Show answer
Answer: D. Distilled water has a higher water potential than the cytoplasm, so water enters by osmosis. Red blood cells have no cell wall to resist the pressure, so they burst.
5. Agar cubes of side 1 cm, 2 cm and 3 cm are placed in acid. What is the surface area to volume ratio of the 2 cm cube?
A
4 : 1
B
6 : 1
C
3 : 1
D
2 : 1
Show answer
Answer: C. For the 2 cm cube, surface area = 6 × 2 × 2 = 24 cm² and volume = 2 × 2 × 2 = 8 cm³, so the ratio is 24 : 8 = 3 : 1. The 1 cm cube is 6 : 1 and the 3 cm cube is 2 : 1, so smaller cubes have larger ratios and the acid reaches their centre faster.
6. Why does a non-woody plant wilt when it is short of water?
A
its cell walls break down when there is too little water, so the stem collapses
B
its cells take in too much water and burst, so the stem falls over
C
its cells lose water and become flaccid, so they no longer support the plant
D
its stomata close, so photosynthesis stops and the leaves lose their support
Show answer
Answer: C. Non-woody plants are held up by turgid cells pressing against their walls. If water is short the cells become flaccid and the plant wilts.
7. Where does the energy for diffusion come from?
A
energy supplied by carrier proteins in the cell membrane
B
energy released from glucose by respiration in the cell
C
light energy absorbed by chlorophyll in the cell
D
the kinetic energy of the random movement of the particles
Show answer
Answer: D. Diffusion is passive: particles move randomly because of their own kinetic energy, so the cell does not use energy from respiration.
8. Which describes osmosis?
A
the net movement of solute molecules from a dilute to a concentrated solution through a partially permeable membrane
B
the net movement of water from a region of higher water potential to a region of lower water potential through a partially permeable membrane
C
the net movement of water from a region of lower water potential to a region of higher water potential through a partially permeable membrane
D
the movement of water molecules through a fully permeable membrane using energy from respiration
Show answer
Answer: B. Osmosis is the net movement of water molecules from a higher to a lower water potential through a partially permeable membrane. The direction and the type of membrane both matter.
9. Identical potato cylinders are left for one hour in sugar solutions of different concentrations. Their percentage change in mass is: 0.0 mol/dm3, +12%; 0.2 mol/dm3, +5%; 0.4 mol/dm3, −3%; 0.6 mol/dm3, −10%. What is the best estimate of the concentration of the potato cell sap?
A
about 0.6 mol/dm3
B
about 0.5 mol/dm3
C
about 0.3 mol/dm3
D
about 0.1 mol/dm3
Show answer
Answer: C. The cell sap has the same water potential as the solution in which there is no change in mass. The change goes from +5% to −3% between 0.2 and 0.4 mol/dm³, so it is zero at about 0.3 mol/dm³.
10. A poison stops respiration in cells. Which process will stop as a result?
A
osmosis into root hair cells
B
diffusion of carbon dioxide out of cells
C
active transport of ions into cells
D
diffusion of oxygen into cells
Show answer
Answer: C. Only active transport needs energy from respiration. Diffusion and osmosis are passive and continue.
Movement into and out of cells: questions students ask
How many Movement into and out of cells MCQs are there?
21, each with the answer and a short explanation, across 2 topics: Diffusion and osmosis, Active transport. Every chapter test draws ten of them, so you can take it many times.
Is the O Level / IGCSE Biology chapter 3 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
