GuidesBiologyPaper 2 · last-minute revision
3 days to go

GCSE Biology Paper 2: last-minute revision

Three days left. Paper 2 covers the nervous system, hormones, genetics and ecology, and it's the paper where required practicals on reaction time and field sampling quietly cost marks. Here's where to spend your time.

AQA 8461 (topics apply broadly to Edexcel and OCR)
The plan

Your 3-day plan

One focus per day, building to a timed run. Work it in order.

3
3 days to go

Homeostasis and the nervous system

  • Learn the reflex arc in order: stimulus, receptor, sensory neurone, relay neurone (in the CNS), motor neurone, effector, response. Be able to explain why reflexes are faster than a conscious response.
  • Revise the required practical on reaction time: the method, what's being controlled, and how to reduce error by repeating and averaging results.
  • Go through hormonal control of blood glucose: insulin, glucagon, and how the body responds to blood glucose being too high or too low. Diabetes (Type 1 and Type 2) is commonly tested alongside this.
2
2 days to go

Inheritance, variation and evolution

  • Practise Punnett square questions until they're automatic: dominant and recessive alleles, genotype vs phenotype, and predicting ratios of offspring.
  • Learn the structure of DNA and the difference between a gene, a chromosome and an allele. These terms get mixed up under exam pressure, so drill the definitions.
  • Revise Darwin's theory of evolution by natural selection and be ready to apply it to an unfamiliar example. Examiners love giving you a species you've never seen and asking you to explain why it evolved.
1
1 day to go

Ecology and a full past paper

  • Revise the required practical on sampling techniques, quadrats and transects, including how to estimate population size across a whole area from a sample, and why random placement matters.
  • Go through the carbon cycle and the water cycle diagrams until you can redraw and label each stage from memory.
  • Sit one full past paper under timed conditions and mark it against the scheme. Pay particular attention to any 6-mark questions on the nervous system, plant hormones or genetics, since these carry the most marks per question on this paper.
Priority order

The topics that come up most

Ranked from analysed past papers. Start at the top: if you run out of time, you will have covered the most-tested ground.

1

The nervous system and reflex arc

The nervous system is consistently one of the most heavily examined topics on this paper. Reflex arc diagrams, synapse function and reaction time questions come up together in multi-part questions.

2

Reflex arc and reaction time required practical

The reaction time practical is examined almost every year, usually asking students to identify variables, explain sources of error, or interpret a results table.

3

Plant hormones (auxin and tropisms)

When plant hormones appear on the paper they tend to carry large marks in a single extended question, covering phototropism, gravitropism and the auxin/seedling growth required practical together.

4

Blood glucose regulation

Insulin and glucagon control of blood glucose, plus the difference between Type 1 and Type 2 diabetes, is a reliable source of multi-mark questions on this paper.

5

The human endocrine system

Understanding hormones as chemical messengers, the role of glands, and how the endocrine system differs from the nervous system underpins several other questions on this paper.

6

Genetic inheritance and Punnett squares

Genetic diagrams are a guaranteed calculation-style question. Practise them until predicting genotype and phenotype ratios is automatic, including inherited disorders.

7

Evolution and natural selection

Almost always tested using an unfamiliar example organism. You need to apply Darwin's theory to new information, not just recite the definition.

8

Ecosystems, sampling and the carbon cycle

Quadrat and transect sampling technique, plus redrawing the carbon and water cycles from memory, are dependable sources of marks that are easy to lose through vague answers.

Your Knowledge Organisers

PrepWise has a one-page Knowledge Organiser for every topic above. In your final 3 days, use them the same way each time: cover the page, try to recall everything from memory, uncover and check what you missed, then repeat that topic again tomorrow.

Open the Biology Knowledge Organisers
Cheat sheet

Exam technique

Rules specific to Paper 2. On this paper, structure earns as many marks as knowledge.

1

Redraw the reflex arc and both cycles from memory

The reflex arc, the carbon cycle and the water cycle are all diagram-based topics that reward students who can redraw them unprompted, with every arrow and label correct. It's not enough to just recognise a completed version. Practise from a blank page, not by reading over a finished diagram.

2

Genetic diagrams: show your Punnett square every time

Even when the question only asks for a ratio, draw the full cross. It's faster than trying to work it out in your head, and if your final ratio is wrong you can still pick up method marks for a correctly set-up diagram.

3

6-mark questions on this paper often combine two topics

Expect questions that link the nervous system with reaction time, or plant hormones with the seedling growth practical. Structure your answer to move logically between the two linked ideas rather than answering them as separate blocks.

4

Required practical questions test control of variables

For both the reaction time and quadrat/transect practicals, be ready to name a variable that should be controlled, explain why, and suggest how repeating readings improves reliability.

Avoid these

5 mistakes that cost marks

The errors examiners see most on this paper. Each one is an easy mark you already know how to keep.

Mixing up gene, allele and chromosomeA chromosome is made of DNA and carries many genes. A gene is a section of DNA that codes for a characteristic. An allele is a different version of that gene. Know all three definitions cold. Examiners test them directly.

Saying insulin 'makes' glucose or 'creates' glycogenInsulin causes the liver to convert glucose into glycogen for storage. It doesn't create the glucose itself. Be precise about what the hormone actually does to blood glucose levels.

Describing natural selection without applying it to the example givenIf the question gives you a specific organism, your answer must reference that organism's variation, survival advantage and reproduction. A generic definition of natural selection alone won't get full marks.

Forgetting that a quadrat only samples part of the areaTo estimate a population across a whole habitat, you must multiply the mean count per quadrat by the total number of quadrats that would fit in the area. It's a common calculation students skip or get backwards.

Confusing tropism direction: auxin doesn't always promote growth in the same placeIn shoots, auxin accumulates on the shaded side and promotes elongation there, bending the shoot towards light. In roots, higher auxin concentration inhibits growth, bending the root away from light. Learn both directions separately. Don't assume they work the same way.

Exam day

The morning of the exam

The 60 minutes before you walk in. Review what you know and settle your nerves.

  • Redraw the reflex arc, the carbon cycle and the water cycle from memory one final time.
  • Recap insulin vs glucagon in one sentence each: what triggers them and what they do.
  • Remind yourself of the auxin rule: shoots bend towards light, roots bend away.
  • Check you have a black pen, a spare pen, and a ruler for drawing genetic diagrams.
  • Do not attempt new topics this morning. Only review what you already know.
  • Eat something before you go in. A blood glucose crash mid-exam is avoidable.

Now test yourself

Reading this plan is not the same as being able to do it. Answer exam-style Biology questions in PrepWise, get them marked in seconds, and find the gaps while you still have time to fix them.

Practise Biology questions

Start the 3-day plan now

Open the Biology Knowledge Organisers, quiz every priority topic and walk in ready. Free during alpha.

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