GCSE Biology (AQA) chapter 2: Organisation MCQs with answers

By Team Megalecture · Updated 4 Nov 2026

48 exam-style questions on Organisation, 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.

48 questions · 4 topics · 10 per test

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What chapter 2 covers

Ten Organisation questions with answers

Try each one, then open the answer. These ten stay the same; the test draws new ones every time.

1. How does an increase in air humidity affect the rate of transpiration, and why?

  1. A
    it increases, because the plant has more water available
  2. B
    it falls, because the diffusion gradient is smaller
  3. C
    it increases, because the stomata open wider in moist air
  4. D
    it is unchanged, because humidity only affects the roots
Show answer

Answer: B. In humid air there is less difference in water vapour concentration between inside and outside the leaf, so water vapour diffuses out more slowly.

2. In an amylase investigation, the rate is calculated as 1000 ÷ time. At pH 7 the starch had all been broken down after 40 seconds. What is the rate?

  1. A
    0.025 s−1
  2. B
    8.3 s−1
  3. C
    25 s−1
  4. D
    40 s−1
Show answer

Answer: C. Rate = 1000 ÷ 40 = 25 s−1.

3. What causes coronary heart disease?

  1. A
    a faulty valve lets blood flow backwards through the heart
  2. B
    fatty material builds up inside the coronary arteries, narrowing them
  3. C
    the pacemaker cells stop sending signals to the ventricles
  4. D
    blood clots from the legs blocking the pulmonary artery
Show answer

Answer: B. Fatty deposits narrow the coronary arteries, reducing the flow of blood, and so oxygen, to the heart muscle.

4. How is the spongy mesophyll adapted to its function?

  1. A
    a waxy cuticle reduces water loss from the cells
  2. B
    air spaces allow gases to diffuse through the leaf
  3. C
    it is made of dead hollow cells that carry water
  4. D
    sieve plates in its cells allow sugar to move through
Show answer

Answer: B. The air spaces let carbon dioxide diffuse to the photosynthesising cells and oxygen and water vapour diffuse out.

5. Which leaf tissue carries out most of the photosynthesis?

  1. A
    the upper epidermis and cuticle
  2. B
    the palisade mesophyll
  3. C
    the spongy mesophyll layer
  4. D
    the xylem and phloem in the veins
Show answer

Answer: B. Palisade cells are packed with chloroplasts and lie near the top of the leaf where light is brightest.

6. The enzyme sucrase breaks down sucrose but has no effect on maltose. What is the best explanation?

  1. A
    only sucrose has a shape that fits the active site of sucrase
  2. B
    maltose stops sucrase working as soon as it is added
  3. C
    sucrase is used up once it has broken down some sucrose
  4. D
    maltose is too small to reach the active site of sucrase
Show answer

Answer: A. Only sucrose has a shape complementary to the active site of sucrase, so only sucrose is a substrate. Enzymes are not used up, and each enzyme is specific to its own substrate.

7. Which chamber of the heart pumps blood to the rest of the body?

  1. A
    right atrium
  2. B
    left atrium
  3. C
    right ventricle
  4. D
    left ventricle
Show answer

Answer: D. The left ventricle pumps blood into the aorta to the body. The right ventricle pumps blood to the lungs.

8. On a hot, dry day a plant loses water faster than its roots can take it up, and the guard cells become flaccid. What happens next?

  1. A
    the stomata open wider to let more air reach the leaf
  2. B
    the stomata close, reducing water loss and gas exchange
  3. C
    the stomata stay open but the cuticle stops water loss
  4. D
    the guard cells burst, leaving the stomata permanently open
Show answer

Answer: B. Flaccid guard cells close the stomata, which cuts water loss by transpiration but also reduces the uptake of carbon dioxide for photosynthesis. Guard cells swell and open the stomata when they are turgid.

9. How does a stent help a patient with coronary heart disease?

  1. A
    it lowers the level of cholesterol in the blood
  2. B
    it replaces a faulty valve with an artificial one
  3. C
    it holds a narrowed coronary artery open so blood can flow
  4. D
    it makes the heart beat at a regular rate
Show answer

Answer: C. A stent is a mesh tube placed in the narrowed artery to hold it open. Statins lower cholesterol; pacemakers correct heart rhythm.

10. Two tubes each contain milk, sodium carbonate solution, phenolphthalein and lipase. Bile is added to tube 2 only. Tube 2 turns colourless after 3 minutes and tube 1 after 9 minutes. What is the best explanation for the difference?

  1. A
    bile is an enzyme that also breaks down fat
  2. B
    bile provided extra lipase to speed up digestion
  3. C
    emulsified fat gave the lipase a larger surface area
  4. D
    bile lowered the pH by adding fatty acids to the tube
Show answer

Answer: C. Bile emulsifies fat into tiny droplets, increasing the surface area on which lipase can act, so the fat is digested faster. Bile is not an enzyme and contains no lipase. It is alkaline, so it does not lower the pH.

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Ways to practise this chapter

Organisation: questions students ask

How many Organisation MCQs are there?

48, each with the answer and a short explanation, across 4 topics: 4.2.1–4.2.2.1 Principles of organisation and the digestive system, 4.2.2.2–4.2.2.3 The heart, blood vessels and blood, 4.2.2.4–4.2.2.7 Coronary heart disease and non-communicable diseases, 4.2.3 Plant tissues, organs and organ systems. Every chapter test draws ten of them, so you can take it many times.

Is the GCSE Biology (AQA) chapter 2 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.

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