Cambridge AS & A Level Biology 9700/12 is the May/June 2026 Paper 1 (Multiple Choice), variant 2. It has 40 questions worth one mark each, lasts 1 hour 15 minutes and tests the AS Level content. Every question is compulsory, and the paper covers all eleven AS topic areas, from cell structure to immunity. Biological molecules carried the most questions (eight), including a water-counting calculation on amylose hydrolysis. This guide gives the official answer to every question, the topic it tested and the reasoning or working behind it. 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.

9700/12 at a glance

Syllabus area	Questions	Number of questions
Cell structure	1–6	6
Biological molecules	7–14	8
Enzymes	15–16	2
Cell membranes and transport	17–20	4
The mitotic cell cycle	21–23	3
Nucleic acids and protein synthesis	24–27	4
Transport in plants	28–30	3
Transport in mammals	31–34	4
Gas exchange	35–36	2
Infectious diseases	37–38	2
Immunity	39–40	2
Total		40

Each correct answer scores one mark, so the total is 40. You answer all forty questions in soft pencil on the answer sheet.

Answer key and topic for every question

Question	What it tested	Answer
1	Width of a plant cell membrane from a 2 nm scale bar	C
2	Resolution and whether structures 75 µm apart can be distinguished	D
3	Organelle holding pathogen material in a macrophage	B
4	Where labelled nucleotides first become concentrated in a cell	C
5	Structures present in typical animal and plant cells	B
6	Feature shared by eukaryotic and prokaryotic cells	B
7	Benedict’s test results for a disaccharide from starch	A
8	General formula of starch	D
9	Advantage of covalent bonds in polymers	A
10	Water molecules needed to hydrolyse two amylose molecules	B
11	Comparing triglyceride and phospholipid structure	D
12	Statement describing only the tertiary structure of FSH	A
13	Statements about the structure of haemoglobin	C
14	A reaction needing water, and why high specific heat capacity helps	C
15	Why a mutated enzyme catalyses a slower reaction	D
16	Essential feature of drugs that target HIV protease	D
17	Positions of molecules in the cell surface membrane	C
18	Plant tissue strips in sucrose solutions: turgidity and water potential	A
19	How molecules too large for membrane proteins enter a cell	B
20	Agar block that takes longest to lose its colour in acid	B
21	Events that decrease as brain stem cells fall with age	C
22	First phase of mitosis affected by drugs that stop spindle formation	C
23	Order of plant cells through one mitotic cell cycle	B
24	How nucleotide-like antiviral drugs reduce nucleic acid synthesis	D
25	Effect of inhibiting DNA ligase on DNA replication	D
26	Post-transcriptional modification of RNA	C
27	Mutation types that always change the primary structure	B
28	Plan diagram of a transverse section of a dicotyledonous stem	B
29	Function of a structure in an electron micrograph of a leaf	A
30	How water moves in xylem vessel elements	A
31	Correct statement about the pulmonary artery	D
32	Axes and point of highest saturation on an oxygen dissociation curve	B
33	Carbon dioxide transport pathway in a red blood cell	A
34	Order in which heart chambers contract, from wall thickness	A
35	Phospholipid bilayers crossed by oxygen from alveolus to haemoglobin	B
36	Function of squamous epithelial cells in the gas exchange system	C
37	Statements about tuberculosis	B
38	A cause, consequence and response to antibiotic resistance	A
39	Type of blood cell that produces memory cells	D
40	Natural passive immunity	B

What the paper tested, topic by topic

Cell structure (Questions 1–6)

• Membrane width (Question 1): measure the membrane against the 2 nm scale bar beside the diagram. It comes out at about 7.5 nm, and 1 nm = 10⁻⁹ m, so the width is 7.5 × 10⁻⁹ m. The other options are the same number in millimetres, micrometres and picometres, so the question is really testing the unit conversion.
• Resolution (Question 2): the term for the level of detail in an image is resolution, not magnification. The student could already tell apart structures 0.05 mm (50 µm) apart, so structures 75 µm apart, which are further apart, can also be distinguished: resolution, yes.
• Organelles (Questions 3 and 4): the structure holding solid material from pathogens in a macrophage is a lysosome. In Question 4, labelled nucleotides are used to make DNA and RNA, so they first concentrate where nucleic acids are made, the nucleus and the mitochondrion (structures 2 and 3).
• Cell comparisons (Questions 5 and 6): the correct table showed centrioles in animal cells only, chloroplasts and plasmodesmata in plant cells only, and Golgi bodies in both. The feature shared by eukaryotes and prokaryotes is circular DNA, which eukaryotic cells have in their mitochondria and chloroplasts. Centrioles, lysosomes and nucleoli are found only in eukaryotes.

Biological molecules (Questions 7–14)

• Amylose hydrolysis (Question 10): each glycosidic bond broken uses one water molecule.
  • Molecule X, 700 glucose units, has 699 bonds. Breaking it fully into glucose needs 699 water molecules.
  • Molecule Y, 300 glucose units, has 299 bonds. Breaking it into maltose gives 150 maltose molecules, and each maltose keeps one bond, so 299 − 150 = 149 bonds are broken.
  • Total: 699 + 149 = 848. Answer 850 comes from forgetting that a chain of n units has n − 1 bonds.
• Food test (Question 7): two α-glucose molecules make maltose, a reducing sugar. It gives a red precipitate with Benedict’s solution straight away, and still does after acid hydrolysis and neutralising, because the products are glucose.
• Formulae and bonds (Questions 8 and 9): starch is (C₆H₁₀O₅)ₙ, one glucose minus one water per unit. Covalent bonds are useful in polymers because they are strong and stable.
• Lipids (Question 11): a triglyceride has three fatty acids and so three ester bonds, while a phospholipid has two fatty acids and two ester bonds.
• Protein structure (Questions 12 and 13): disulfide bonds within the β-subunit of FSH describe tertiary structure only. An α-helix is secondary structure and two subunits together are quaternary structure. For haemoglobin, statement 1 was wrong because the hydrophilic R-groups lie on the outside of the molecule, which leaves answer C (statements 2 and 3).
• Water (Question 14): amylase hydrolyses starch, so its reaction uses water as a reactant. DNA polymerase catalyses condensation reactions, which release water. High specific heat capacity means water needs a lot of energy to raise its temperature; removing heat as it evaporates is a different property.

Enzymes (Questions 15–16)

• Mutated enzyme (Question 15): a change in the active site’s shape makes it less complementary to the substrate, and a raised activation energy also slows the reaction, so the answer was statements 2 and 3.
• HIV protease drugs (Question 16): the essential feature is a specific structure that inhibits only the viral protease, so that the drug does not inhibit the body’s own enzymes.

Cell membranes and transport (Questions 17–20)

• Membrane positions (Question 17): glycolipids and glycoproteins are on the surface, phospholipids extend into the membrane and cholesterol sits between the phospholipid tails.
• Tissue in sucrose (Question 18): the ratio of initial to final length rises as sucrose concentration rises, so the strips get shorter. The cells lose water, become less turgid, and their water potential becomes more negative.
• Bulk transport (Question 19): molecules too large to pass through membrane proteins enter by endocytosis.
• Agar blocks (Question 20): the block with the smallest surface area to volume ratio takes longest to lose its colour.

Block	Surface area (mm²)	Volume (mm³)	SA : V
A, 10 × 10 × 10 mm	600	1000	0.6
B, 20 × 20 × 20 mm	2400	8000	0.3
C, 40 × 20 × 10 mm	2800	8000	0.35
D, 40 × 40 × 5 mm	4000	8000	0.5

Blocks B, C and D have the same volume, so the trap is picking the biggest-looking block (D). The 20 mm cube has the lowest ratio, and the acid also has the furthest to travel to reach its centre.

The mitotic cell cycle (Questions 21–23)

• Stem cells (Question 21): as brain stem cells fall with age, mitosis, cell replacement and tissue repair all decrease. The option that also included “cell repair” was not the answer.
• Spindle drugs (Question 22): the spindle starts to form in prophase, so that is the first phase affected.
• Ordering cells (Question 23): the cycle runs 1 → 3 → 5 → 4 → 2, starting with the cell in interphase and ending with the cell whose chromosomes are being pulled apart.

Nucleic acids and protein synthesis (Questions 24–27)

• Antiviral drugs (Question 24): acyclovir and ganciclovir resemble purine nucleotides. They replace them, so the nucleic acids made are incomplete.
• DNA ligase (Question 25): ligase catalyses the condensation reactions that join nucleotides on the lagging strand, so inhibiting it stops those nucleotides being linked together.
• Splicing (Question 26): the primary transcript has its introns removed and exons joined to form mRNA. Two options reversed introns and exons, and two named the wrong starting molecule.
• Mutations (Question 27): a deletion or an insertion in the coding region always changes the primary structure, but a substitution might not, because the new codon can code for the same amino acid.

Transport in plants (Questions 28–30)

• Dicotyledonous stem (Question 28): a transverse section shows separate vascular bundles, each with xylem and phloem, arranged in a ring. The star-shaped xylem in A is the arrangement of a root, and C and D are longitudinal sections.
• Leaf micrograph (Question 29): structure M is a xylem vessel, whose function is the transport of mineral ions (with water).
• Water in xylem (Question 30): water moves by mass flow, driven by cohesion-tension. Osmosis moves water between cells, not along xylem vessels.

Transport in mammals (Questions 31–34)

• Pulmonary artery (Question 31): it carries blood at a higher pressure than the pulmonary vein. It carries deoxygenated blood away from the heart and does not have a series of valves along its length.
• Dissociation curve (Question 32): partial pressure of oxygen in kPa goes on the x-axis, and haemoglobin is most saturated at point 2, at the top of the curve.
• Carbon dioxide transport (Question 33): carbon dioxide and water are combined by carbonic anhydrase (1) to form carbonic acid (2), which dissociates into hydrogen ions (3), taken up by haemoglobin, and hydrogencarbonate ions (4).
• Cardiac cycle (Question 34): W, with the thickest wall, is the left ventricle and X is the right ventricle. Y and Z, with equal and thinner walls, are the atria. The two ventricles contract together and the two atria contract together, so the only option that pairs the chambers correctly is A.

Gas exchange (Questions 35–36)

• Counting bilayers (Question 35): oxygen crosses into and out of an alveolar epithelial cell (2), into and out of a capillary endothelial cell (2), then into the red blood cell (1): 5 bilayers. Answer A, 3, comes from counting each cell as a single barrier instead of two membranes.
• Squamous epithelium (Question 36): it acts as a thin barrier between the air and the blood. Mucus production and removing dust belong to goblet cells and ciliated cells.

Infectious diseases (Questions 37–38)

• Tuberculosis (Question 37): statements 1 and 2 were correct. Statement 3 was wrong because TB is caused by a bacterium, not a protoctist.
• Antibiotic resistance (Question 38): the only fully correct row was routine use of the same antibiotic (cause), higher average treatment costs (consequence) and testing the pathogen’s sensitivity before prescribing (step). Increasing antibiotic use is the opposite of a solution, and vaccination does not cause resistance.

Immunity (Questions 39–40)

• Memory cells (Question 39): lymphocytes produce memory cells. Phagocytes, neutrophils and macrophages do not.
• Natural passive immunity (Question 40): antibodies received in breast milk. An injection of antibodies is artificial passive immunity, and the two options about stimulating lymphocytes describe active immunity.

Where the marks are on 9700/12

• Biological molecules carried 8 marks and cell structure 6, so these two topics made up 14 of the 40 marks.
• Every one of the eleven AS topic areas was tested, with no area worth fewer than two marks. A gap in any topic costs marks.
• Five questions needed numbers: the membrane width (1), the resolution comparison (2), the amylose water count (10), the agar block ratios (20) and the bilayer count (35).
• Ten questions were built on a diagram, graph or micrograph: 1, 3, 4, 18, 21, 23, 28, 29, 32 and 33. Read the labels and axes before the options.
• Four questions used numbered statements (13, 15, 30 and 37). Decide whether each statement is true on its own before you look at the letter combinations.

How to self-mark 9700/12 with the mark scheme

1. Check each answer against the key above or the official mark scheme. Count one mark per correct letter.
2. Tag every wrong answer by topic, using the at-a-glance table, to see which area is costing the most.
3. Tag it by reason too: knowledge (for example, which phase the spindle forms in), misread (missing “always” in Question 27 or “first” in Questions 4 and 22) or working (an off-by-one bond count in Question 10, or a unit slip in Question 1).
4. Redo the five number-based questions with the working written out, and check that your answer matches the key without guessing between options.
5. Revise knowledge gaps first, then practise statement questions by marking each statement true or false in the margin before choosing a letter.

Sit 9700/12 as a timed mock

You have 75 minutes for 40 questions, just under two minutes each. Use two passes: answer the recall questions first, mark any that need a calculation or careful diagram reading, then come back to them.

Block	Questions	Time
Cell structure and biological molecules	1–14	26 minutes
Enzymes, membranes and the cell cycle	15–23	16 minutes
Nucleic acids and transport in plants	24–30	12 minutes
Transport in mammals, gas exchange, disease and immunity	31–40	15 minutes
Second pass and check the answer sheet	–	6 minutes

The first block is longest because it holds three of the five number-based questions and two protein-structure questions with closely worded options.

Other May/June 2026 9700 papers

• 9700 Paper 22 (AS Level Structured Questions)
• 9700 Paper 32 (Advanced Practical Skills)
• 9700 Paper 42 (A Level Structured Questions)
• 9700 Paper 52 (Planning, Analysis and Evaluation)

Practise and download

• Download 9700/12 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 topics were on 9700 Paper 12 May/June 2026? +

All eleven AS topic areas. Biological molecules had 8 questions, cell structure 6, cell membranes and transport 4, nucleic acids and protein synthesis 4, transport in mammals 4, the mitotic cell cycle 3, transport in plants 3, and enzymes, gas exchange, infectious diseases and immunity 2 each.

How many marks is 9700/12 and how long is it? +

It has 40 multiple choice questions, one mark each, for a total of 40 marks. You have 1 hour 15 minutes, you answer on a multiple choice answer sheet and you may use a calculator.

Is 9700/12 an AS Level or A Level paper? +

Paper 1 tests the AS Level content. It is sat by AS candidates with Papers 2 and 3, and by full A Level candidates with Papers 2, 3, 4 and 5.

What was the answer to the amylose hydrolysis question on 9700/12? +

B, 848 water molecules. Breaking the 700-glucose chain into glucose takes 699 water molecules. Breaking the 300-glucose chain into 150 maltose molecules breaks 299 − 150 = 149 bonds. 699 + 149 = 848.

How many phospholipid bilayers does oxygen cross on 9700/12 Question 35? +

Five, so the answer is B. Oxygen goes into and out of an alveolar epithelial cell (two), into and out of a capillary endothelial cell (two), and into the red blood cell (one).

Where can I download 9700/12 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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