AQA GCSE Biology Paper 2 practice questions

What is on Paper 2?

• Paper 2 covers the second half of the course: homeostasis and response, inheritance, variation and evolution, and ecology.
• It is a written paper of 1 hour 45 minutes, worth 100 marks — 50% of the GCSE.
• Questions are a mix of multiple choice, structured, closed short answer and extended response.
• Required practicals and maths or data skills from anywhere in the course can appear, so they are worth revising alongside the Paper 2 topics.

Paper 2 practice questions with answers

10 original questions across the 5 Paper 2 topics. Try each one before reading the answer.

1. The nervous system and reflexes

   1. Put the reflex arc in order.

   Answer: Stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector → response

   Learn this sequence word for word.

2. The nervous system and reflexes

   2. Why are reflex actions fast?

   • • They involve fewer synapses and skip conscious brain processing
   • • The impulse travels as light
   • • They use hormones
   • • They only happen in the hand

   Answer: They involve fewer synapses and skip conscious brain processing

   Speed protects the body from harm.

3. Hormones and blood glucose

   3. Which organ monitors and controls blood glucose concentration?

   • • Liver
   • • Pancreas
   • • Kidney
   • • Pituitary

   Answer: Pancreas

   It detects the level and releases insulin or glucagon.

4. Hormones and blood glucose

   4. Describe what happens when blood glucose rises after a meal.

   Answer: The pancreas releases insulin; glucose moves into liver and muscle cells and is stored as glycogen, lowering blood glucose.

   Insulin → storage as glycogen → level falls.

5. Genetics and inheritance

   5. Two heterozygous parents (Bb × Bb) have a child. What is the probability of a recessive phenotype?

   • • 0%
   • • 25%
   • • 50%
   • • 75%

   Answer: 25%

   Only bb shows the recessive phenotype — 1 in 4.

6. Genetics and inheritance

   6. Define phenotype.

   Answer: The physical characteristics an organism shows, resulting from its genotype and environment.

   Genotype = alleles; phenotype = what you see.

7. Variation, evolution and selection

   7. Explain how antibiotic-resistant bacteria arise.

   Answer: A random mutation makes some bacteria resistant; the antibiotic kills the rest, the resistant ones survive, reproduce and pass on the allele.

   Mutation → survival → reproduction → spread.

8. Variation, evolution and selection

   8. Which is a disadvantage of selective breeding?

   • • Reduced genetic variation and more inherited disease
   • • It is illegal
   • • It slows plant growth
   • • It causes mutations in humans

   Answer: Reduced genetic variation and more inherited disease

   Inbreeding reduces the gene pool.

9. Ecosystems and adaptations

   9. Which of these is an abiotic factor?

   • • Predators
   • • Light intensity
   • • Disease
   • • Competition

   Answer: Light intensity

   Abiotic = non-living.

10. Ecosystems and adaptations

    10. Explain why removing a predator can reduce biodiversity.

    Answer: Prey numbers rise, they over-consume their food source, so other species decline or die out.

    Follow the chain through the food web.

Where Paper 2 marks are usually lost

• Describing a control mechanism without naming the receptor, coordinator and effector — examiners want the pathway, not just the outcome.
• Writing 'the body adjusts' or 'the level goes back to normal' instead of naming the hormone or nerve involved and the direction of the change.
• Answering genetic cross questions without drawing the Punnett square, then stating a ratio the working does not support.
• Giving one adaptation when the question says 'explain', which needs the adaptation and the survival advantage it produces.
• Quoting numbers from a graph without units, or reading the axis scale wrongly on ecology data questions.

How to answer the 6-mark extended response

• Spend the first 30 seconds underlining the command word and the number of things being compared — most 6-markers are secretly two 3-mark answers.
• Plan three points that each carry a scientific term, then a consequence for each. Six short linked sentences beat one long paragraph.
• For 'evaluate' questions, include a benefit, a drawback and a judgement sentence at the end. A missing judgement is the most common reason for dropping to 4 marks.
• For required practical questions, mention the control variable and how the result was measured — method detail is where the marks sit.

Timing that works under pressure

• Roughly one mark per minute leaves about 15 minutes spare on a 100-mark, 105-minute paper.
• Bank the multiple choice and one-mark recall questions first, then return to the extended responses with your remaining time.
• If a calculation stalls for more than two minutes, write down the formula and the substituted numbers and move on — method marks are still available.
• Leave five minutes to check units, significant figures and whether any question part was skipped over a page break.

A five-minute Paper 2 routine

• Pick one Paper 2 topic and answer five questions on it rather than rereading a whole revision guide.
• Mark them immediately and write one sentence about why each wrong answer was wrong.
• Repeat the same five questions two days later — the second attempt is what moves the knowledge into recall.
• Rotate topics so homeostasis, inheritance and ecology each come round twice a week.

Revise each Paper 2 topic

• The nervous system and reflexes (54 questions)
• Hormones and blood glucose (54 questions)
• Genetics and inheritance (55 questions)
• Variation, evolution and selection (54 questions)
• Ecosystems and adaptations (54 questions)

AQA Biology Paper 2 FAQs

What topics are on AQA GCSE Biology Paper 2?

Paper 2 assesses homeostasis and response, inheritance, variation and evolution, and ecology. Required practicals and maths and data skills linked to those topics can also be examined.

How long is AQA GCSE Biology Paper 2?

It is a 1 hour 45 minute written exam worth 100 marks, which is 50% of the GCSE. Working at about one mark per minute leaves time to check your answers.

Is Paper 2 harder than Paper 1?

Not inherently, but more of the marks come from explanation and extended response rather than straight recall, so answers need named structures, hormones or ratios rather than general description.

How should I revise for Biology Paper 2?

Practise answering questions rather than rereading notes. Short daily sets of five questions per topic, marked straight away, expose weak areas faster than a long passive revision session.