Cambridge AS & A Level Biology 9700/52 is the May/June 2026 Paper 5 (Planning, Analysis and Evaluation), variant 2. It is an A Level paper, lasts 1 hour 15 minutes and is worth 30 marks. It had two compulsory questions: a 20-mark question on catalase in ripening avocados, which included a 7-mark method, and a 10-mark question on a butterfly survey. This guide goes through each part and shows what the official mark scheme gave marks for. The paper and its mark scheme are free on the Tutopiya Learning Portal.

For an overview of all five 9700 papers from this series, see A Level Biology 9700 May/June 2026 past papers: what came up and how it was marked.

9700/52 at a glance

Question	Part	Marks	Skill
1(a), 1(b)	Catalase in avocados: hazard, independent variable, method	9	Planning
1(c)(i), (ii)	Cold storage study: random selection of trees, humidity	2	Planning
1(c)(iii), (iv)	95% confidence intervals and error bars	3	Data processing and presentation
1(c)(v), (vi)	Conclusions with evidence, why not a t-test	6	Analysis and evaluation
2(a)	Butterfly belt transect: identification, standardised variables, limitations	6	Planning and evaluation
2(b)	Urban against rural diversity	2	Prediction and explanation
2(c)	Percentage increase in cabbage white butterflies	2	Calculation
	Total	30

Question-by-question walkthrough

Question 1: catalase in ripening avocados (20 marks)

Avocados ripen only after harvesting: the skin changes from bright green to dark purple and the mesocarp softens. Mesocarp cells contain catalase, which breaks hydrogen peroxide down into water and oxygen, and the amount of catalase changes as the fruit ripens. A student saw bubbles of oxygen form on pieces of mesocarp in hydrogen peroxide.

• Hazard, risk and precaution, 1(a) (1 mark): all three were needed for the mark. The mark scheme’s combinations: a knife or scalpel, risk of cuts, cut away from the hand or onto a board; the avocado or its catalase, risk of an allergy or irritation, wear gloves; hydrogen peroxide, which is an irritant, toxic or corrosive or can damage the eyes, wear gloves, goggles or safety glasses. “Hydrogen peroxide is harmful” and “burns” were ignored. “No risk” was rejected, and gloves as the precaution for a knife were ignored.
• Independent variable, 1(b)(i) (1 mark): the time after harvesting, or the stage (degree) of ripeness. Skin colour or the softness of the mesocarp was accepted. “Ripeness” or “time” on its own and “age” were ignored.
• Method, 1(b)(ii) (7 marks): one mark for using five different stages of ripeness, then any six from:
  1. pieces of mesocarp with the same stated dimensions, such as cubes or cylinders of stated size (“same size” or “same mass” alone was ignored);
  2. cutting them with a knife and ruler, or a cork borer and ruler;
  3. the same avocado variety, or the same number of pieces in each test;
  4. a suitable way to keep the hydrogen peroxide at constant temperature, such as a water bath (a stated temperature had to be between 10 °C and 40 °C);
  5. the same volume and concentration of hydrogen peroxide;
  6. adding the avocado to the hydrogen peroxide and starting the timer straight away;
  7. a suitable way to measure the oxygen, such as a gas syringe, collecting it over water in an inverted measuring cylinder, the height of foam with washing-up liquid, or loss of mass on a balance (“count bubbles” on its own was ignored);
  8. a fixed time for each stage of ripeness;
  9. at least three measurements at each stage;
  10. fresh hydrogen peroxide for each test.

Part (c) described a study by scientists. They took one mature avocado from each of 100 trees chosen at random, tested 10 straight after harvest and stored 30 in each of three groups at 7 °C and 85% humidity for 10, 20 or 30 days. Five from each group were tested after storage (groups 10d, 20d, 30d), and five more after being left at 20 °C to ripen (groups 10dR, 20dR, 30dR).

• Choosing trees at random, 1(c)(i) (1 mark): number every tree and use a random number generator to pick them. Quadrats and coordinates were ignored.
• Why 85% humidity, 1(c)(ii) (1 mark): to reduce water loss (transpiration or evaporation) from the avocados during storage. “Keep moist” and “prevent drying out” were ignored.
• Confidence intervals, 1(c)(iii) (1 mark): using mean ± (2 × SE), 822 ± 412 for 20dR and 736 ± 358 for 30dR. Both were needed.
• Error bars, 1(c)(iv) (2 marks): one mark per bar, plotted to within half a square: 410 to 1234 for 20dR and 378 to 1094 for 30dR. Wrong values carried forward from 1(c)(iii) could still score.
• Conclusions with evidence, 1(c)(v) (4 marks, any four):
  1. cold storage alone has a variable effect on catalase activity: it rises and falls with no clear trend;
  2. data to show this, such as 571 at 0d against 615 at 10d and 455 at 20d (only after the first point);
  3. avocados left to ripen after storage have higher mean activity than those tested straight after storage, or than 0d;
  4. data to show this, such as 455 for 20d against 822 for 20dR (only after the third point);
  5. the error bars overlap, so there may be no significant difference between the groups. Points 2 and 4 only count if you have also made the matching conclusion.
• Why not a t-test, 1(c)(vi) (2 marks, any two): the data may not be normally distributed; the standard deviations are different; there are more than two means to compare (seven groups). “Not continuous”, “discrete” or “categoric” data was rejected.

Question 2: a butterfly survey (10 marks)

Members of the public helped scientists estimate UK butterfly populations by walking slowly along a transect and identifying and counting every butterfly within 2.5 m on each side of the line.

• Identifying species, 2(a)(i) (1 mark): an identification key, guide book, app, database or expert. “Photographs” without more detail was ignored.
• Two other standardised variables, 2(a)(ii) (2 marks, any two): the length of the transect; the same person counting; the time of day; the time of year or season; the time spent counting. Weather and “time” on its own were ignored.
• Limitations of the method, 2(a)(iii) (3 marks, any three): each mark needed a limitation and its effect. For counting, butterflies fly and move about, so some are counted twice or missed; small or camouflaged butterflies are missed; the 2.5 m distance is hard to judge; a fast walker misses some. For identification, butterflies in flight or very small ones are hard to see clearly; some species look alike; the person may lack the knowledge or be unable to see clearly; walking too fast leads to misidentification. “Human error” was ignored.
• Urban or rural diversity, 2(b) (2 marks): either prediction could score, as long as the explanation supported it. Points for rural areas included more variety of food plants and flowers, more habitats or niches, and fewer fragmented habitats; points for urban areas included more gardens and parks and warmer temperatures. Qualified points about pesticides and active conservation worked either way. Predators, pollution, light and “greenery” were ignored.
• Percentage increase, 2(c) (2 marks): from Figure 2.2, the highest daily count rose from 2300 in 2012 to 13 500 in 2013. (13 500 − 2300) ÷ 2300 × 100 = 11 200 ÷ 2300 × 100 = 487% to three significant figures. The working earned one mark and the answer the other. An answer not given to three significant figures was rejected, and a correct answer with no working scored only 1.

Where the marks are on 9700/52

• Planning carried 14 marks: the risk assessment (1), independent variable (1), method (7), random sampling (1), humidity (1), identifying butterflies (1) and standardised variables (2).
• Conclusions and evaluation carried 11 marks: the conclusions with evidence (4), the t-test (2), the transect limitations (3) and the diversity prediction (2).
• Data processing and presentation carried 5 marks: the confidence intervals (1), the error bars (2) and the percentage increase (2).
• The 7-mark method is almost a quarter of the paper. Each mark is for one specific, practical detail, so vague statements such as “keep variables the same” score nothing.

How to self-mark 9700/52 with the mark scheme

1. Learn the abbreviations first. A semicolon separates marking points, a slash shows alternatives, A means accept, R means reject, I means ignore, AW means alternative wording, ora means or reverse argument, ecf means error carried forward and AVP means alternative valid point.
2. Mark the method as a checklist. Award the five-stages mark first, then tick each of the ten listed points you included and stop at six more.
3. Look for numbers and units. “Same size” scored nothing; stated dimensions with units did. The same applies to temperature: a stated value had to be between 10 °C and 40 °C.
4. Check the paired points in 1(c)(v). Give the data marks only where you also made the conclusion they support.
5. Check your error bars against 410 to 1234 and 378 to 1094.
6. Be strict with significant figures. 487% is the only accepted form in 2(c).

Sit 9700/52 as a timed mock

The paper allows 75 minutes for 30 marks, two and a half minutes per mark. A workable plan:

Block	Marks	Time
Question 1(a) and 1(b): hazard, variable and method	9	22 minutes
Question 1(c): cold storage data	11	25 minutes
Question 2: butterfly survey	10	22 minutes
Check calculations, error bars and significant figures	–	6 minutes

Plan the method as a numbered list first: what you change, how you measure, what you keep the same and how many repeats.

Other May/June 2026 9700 papers

• 9700 Paper 12 (Multiple Choice)
• 9700 Paper 22 (AS Level Structured Questions)
• 9700 Paper 32 (Advanced Practical Skills)
• 9700 Paper 42 (A Level Structured Questions)

Practise and download

• Download 9700/52 and its mark scheme on the Learning Portal →
• All 9700 May/June 2026 papers: overview and marking patterns
• Try a free A Level Biology quiz

Need help with a 9700 topic? Book a free trial lesson with an A Level Biology tutor →

Frequently asked questions

What was on 9700 Paper 52 May/June 2026? +

Two questions. Question 1 (20 marks) was about catalase in ripening avocados: a risk assessment, the independent variable, a 7-mark method, random sampling, storage humidity, confidence intervals and error bars, conclusions and why a t-test was unsuitable. Question 2 (10 marks) was a butterfly survey using a modified belt transect.

How many marks is 9700/52 and how long is it? +

It is out of 30 marks and lasts 1 hour 15 minutes. It is an A Level paper with two compulsory questions, and the biggest single part is the 7-mark method in Question 1(b)(ii).

What were the 95% confidence intervals on 9700/52? +

Using mean ± (2 × SE), group 20dR was 822 ± 412 and group 30dR was 736 ± 358. The error bars therefore run from 410 to 1234 and from 378 to 1094 arbitrary units, with one mark for each bar plotted within half a square.

Why was a t-test not suitable on 9700/52? +

The mark scheme accepted any two of: the data may not be normally distributed, the standard deviations are different, and there are more than two means to compare (seven groups). Saying the data were discrete or categoric was rejected.

What was the percentage increase in cabbage white butterflies on 9700/52? +

The highest daily count rose from 2300 in 2012 to 13 500 in 2013, so the increase is 11 200 ÷ 2300 × 100 = 487%. The answer had to be to three significant figures, and a correct answer with no working scored only 1 of 2.

Where can I download 9700/52 May/June 2026 and its mark scheme? +

Both are free to download and print on the Tutopiya Learning Portal, on the Cambridge AS & A Level Biology 9700 past papers page.

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