Lesson 4.1.3.1

4.1.3.1 Diffusion Quiz: AQA Biology, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.1.3.1, Diffusion: 20 multiple choice questions for the AQA GCSE Biology (8461), Unit 1: Cell biology, written with Revision Ninja.

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The 20 questions

  1. How do particles move during diffusion across a concentration gradient?

    • High to low
    • Equal to high
    • Low to equal
    • Low to high

  2. Which factor does not directly affect the rate of diffusion in cells?

    • Light intensity
    • Surface area
    • Concentration gradient
    • Temperature

  3. By which transport process do oxygen and carbon dioxide move during gas exchange?

    • Active transport
    • Endocytosis
    • Osmosis
    • Diffusion

  4. By which transport process does urea move from cells into blood plasma?

    • Active transport
    • Phagocytosis
    • Diffusion
    • Osmosis

  5. A steeper concentration gradient will cause diffusion to:

    • Happen faster
    • Stop completely
    • Reverse direction
    • Happen more slowly

  6. What happens to the rate of diffusion when temperature increases?

    • It increases
    • It stops completely
    • It decreases
    • It stays constant

  7. Which change to a cell membrane increases the rate of diffusion?

    • Smaller surface area
    • Lower temperature
    • Thicker membrane
    • Larger surface area

  8. Why can single-celled organisms rely on diffusion alone for gas exchange?

    • Large surface area
    • Thick cell membrane
    • Small surface area
    • Low surface area

  9. Calculate the surface area to volume ratio of a cube with side 2 cm.

    • 3:1
    • 2:1
    • 1.5:1
    • 6:1

  10. Calculate the surface area to volume ratio of a cube with side 1 cm.

    • 6:1
    • 1:6
    • 2:1
    • 3:1

  11. Calculate the surface area to volume ratio of a cube with side 3 cm.

    • 6:1
    • 2:1
    • 1:2
    • 3:1

  12. What happens to the surface area to volume ratio as an organism increases in size?

    • It stays constant
    • It decreases
    • It doubles
    • It increases

  13. Why do large multicellular organisms require specialised exchange surfaces?

    • Low SA:V ratio
    • Fast active transport
    • High SA:V ratio
    • Thick cell membranes

  14. Which feature of an exchange surface increases its rate of diffusion?

    • Poor blood supply
    • Thin membrane
    • Thick membrane
    • Small surface area

  15. What is the primary function of ventilation at an exchange surface?

    • Thickens membrane walls
    • Shortens diffusion distance
    • Maintains concentration gradient
    • Increases surface area

  16. Which exchange surface is specifically adapted in mammals for absorbing digested food?

    • The bladder
    • The large intestine
    • The gall bladder
    • The small intestine

  17. Which plant organ is primarily adapted for gas exchange?

    • Flower
    • Root tip
    • Stem
    • Leaf

  18. How are fish gills adapted for efficient gas exchange?

    • Thick outer skin
    • Slow blood flow
    • Large surface area
    • Small surface area

  19. Which structures in human lungs provide a large surface area for gas exchange?

    • Trachea
    • Bronchi
    • Capillaries
    • Alveoli

  20. How does a steeper concentration gradient affect the rate of diffusion?

    • Has no effect
    • Stops diffusion entirely
    • Increases the rate
    • Decreases the rate

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