GuidesBiologyPaper 2 · last-minute revision
3 days to go

GCSE Biology OCR B Paper 2: last-minute revision

Three days left. Paper 2 covers respiration and growth, how the human body stays alive, and evolution. Every question opens with a real-world scenario, so you need to apply your knowledge, not just recall it. Here's the plan.

OCR Twenty First Century Science B, J257
The plan

Your 3-day plan

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

3
3 days to go

Explaining life using chemistry (B4): respiration and growth

  • Compare aerobic and anaerobic respiration: the conditions each needs, the inputs and outputs, and why aerobic respiration produces far more ATP. Practise applying this to an exercise or fermentation scenario.
  • Revise the cell cycle: interphase and mitosis, plus meiosis and why it halves the chromosome number to form gametes. You don't need to know the intermediate stages of mitosis or meiosis in detail, just the overall purpose and outcome.
  • Go through stem cells: their role in embryonic and adult animals, and be ready to give a scientific justification (not just an opinion) for whether stem cells should be used to treat disease.
2
2 days to go

The human body: staying alive (B5)

  • Revise how substances get into, out of and around the body: diffusion, osmosis, active transport, and the surface area to volume ratio reason why larger organisms need transport systems.
  • Go through the nervous system and reflex arc pathway, then revise hormonal control: insulin and glucagon in blood glucose regulation, and the role of hormones in the menstrual cycle and contraception.
  • Revise thermoregulation and the kidney's role in water balance, including how ADH affects the permeability of the kidney tubules.
1
1 day to go

Life on Earth: evolution, classification and biodiversity, plus a full past paper

  • Revise Darwin's theory of evolution by natural selection and apply it step by step to an unfamiliar organism: variation, survival advantage, reproduction, and the allele becoming more common over generations.
  • Go through classification and how DNA analysis has changed how organisms are grouped, then revise biodiversity threats and conservation measures.
  • Sit one full past paper under timed conditions and mark it against the scheme. If you're sitting a Depth paper, practise the 6-mark Level of Response question in full continuous prose, not bullet points.
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

Aerobic and anaerobic respiration

Comparing the two types of respiration, including conditions, inputs, outputs and relative ATP yield, is core B4 content that appears across Breadth and Depth papers at both tiers.

2

The nervous system and reflex arc

The nervous system underpins B5 'staying alive' content and is tested through the reflex arc pathway and synapse function on nearly every sitting.

3

Blood glucose regulation

Insulin and glucagon control of blood glucose, and how this can go wrong in diabetes, is one of the most reliable sources of multi-mark questions in the B5 human body content.

4

The human endocrine system

Understanding hormones as chemical messengers, and how the endocrine system compares with the nervous system, underpins several other questions in B5.

5

Evolution and natural selection

Almost always tested using an unfamiliar example organism in B6. You need to apply Darwin's theory to the specific example given, not just define natural selection.

6

Classification and biodiversity

How DNA analysis has changed classification systems, plus biodiversity threats and conservation, are consistently tested in the Life on Earth content.

7

Water regulation and the kidney

Kidney function and ADH's role in controlling water balance is tested at both Foundation and Higher tier, with more mechanistic detail expected at Higher.

8

Mitosis, meiosis and stem cells

The cell cycle and the difference between mitosis and meiosis, plus stem cell uses and ethics, are reliably tested, often alongside a 'should we...?' evaluation question.

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

Every question starts with a scenario: find the biology inside it

OCR B never asks bare recall questions. Read the context carefully first, identify which topic it's really testing, then apply what you know. This matters most on B5, where scenarios often involve a medical condition or a specific patient case.

2

Depth papers include the 6-mark Level of Response question; Breadth papers do not

If you're sitting a Depth paper, expect one asterisked extended-writing question marked against level descriptors. Write in continuous prose covering the process in a logical order, not bullet points, since examiner reports consistently flag bullet-point answers losing the top level.

3

Apply natural selection to the exact organism given

Your answer must reference that organism's specific variation and advantage, in order: variation exists, it gives a survival or reproductive advantage, more individuals with that allele survive to reproduce. A generic definition alone loses marks.

4

'Should we...?' questions need scientific justification, not opinion

Stem cell use is a common OCR B evaluation topic. Give a specific scientific reason for and against, then reach a justified conclusion. A one-sided opinion or a vague answer loses marks.

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 the products of aerobic and anaerobic respirationAerobic respiration needs oxygen and produces carbon dioxide and water, releasing far more ATP. Anaerobic respiration in humans produces lactic acid and does not need oxygen, but releases much less ATP. Keep the yield comparison in your answer, not just the equation.

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

Writing 'survival of the fittest' as the whole answer on natural selectionThat phrase alone earns no marks. You need the full chain: variation exists, some variants have an advantage, those individuals are more likely to survive and reproduce, so the allele becomes more common over generations.

Confusing mitosis and meiosisMitosis produces two genetically identical cells for growth and repair. Meiosis produces four genetically different gametes with half the chromosome number. If the question mentions gametes or fertilisation, it's meiosis.

Reversing answers in a true/false table under time pressureSlow down on true/false tables specifically. It's easy to tick the wrong column when working quickly, and this is flagged as a common, avoidable error in OCR B examiner reports.

Exam day

The morning of the exam

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

  • Recap insulin vs glucagon in one sentence each: what triggers them and what they do.
  • Say the natural selection chain out loud once: variation, advantage, survival, reproduction, more common allele.
  • Check you have a black pen, a spare pen, and a ruler for drawing diagrams.
  • Do not attempt new topics this morning. Only review what you already know.
  • Remind yourself: every question has a scenario first. Find the biology being tested before you answer.
  • 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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