Are these real mark scheme answers?

The context and data are described in our own words, not reproduced, and the worked answers are written entirely by us, aimed at the actual level descriptors of the real AQA mark schemes for each sitting. They are not copied from AQA's own exemplar materials, since that would breach copyright, but they are built to hit exactly what the real mark scheme rewarded that year. PrepWise is independent of AQA and not endorsed by them.

Will the exact same questions come up again this year?

The Punnett square question returns in some form in every single sitting we analysed, and evolution, plant hormones, temperature regulation and glucose regulation all return regularly too. But you cannot rely on repeats alone, since the exact condition, numbers and context change every time even when the question type is similar. Use this page to see which TOPICS and QUESTION TYPES keep returning and make sure you know the underlying biology cold, whatever the exact wording turns out to be.

Is PrepWise free to use for this?

Yes, PrepWise is free during alpha. You can practise every topic on this page without paying anything right now.

Person 7 and person 8 in Figure 6 are expecting a fourth child. What is the probability of the child having Dupuytren's?

Person 7 has Dupuytren's, caused by the dominant allele D, and from earlier working in the question is known to be heterozygous, Dd. Person 8 does not have Dupuytren's and so is homozygous recessive, dd. Person 7's gametes are therefore D and d, and person 8's gametes are both d. Drawing a Punnett square with person 7's gametes D and d along the top and person 8's gametes d and d down the side gives four offspring genotypes: Dd, Dd, dd and dd. The genotypes Dd have Dupuytren's, since D is dominant, while the genotypes dd do not have Dupuytren's. This means two of the four possible offspring, or half, would have Dupuytren's.

Persons 8 and 9 in Figure 14 are expecting a second child. Determine the probability that the child will be a girl with sickle cell trait.

Person 8 does not have sickle cell anaemia or trait, so is homozygous for the normal allele, HAHA, giving gametes of HA and HA. Person 9 has sickle cell trait, meaning she is heterozygous, HAHS, giving gametes of HA and HS. Crossing person 8's gametes (HA and HA) with person 9's gametes (HA and HS) in a Punnett square gives four offspring genotypes: HAHA, HAHA, HAHS and HAHS. The genotypes HAHA do not have sickle cell anaemia or trait, while the genotypes HAHS have sickle cell trait but are generally healthy. Since sex is inherited separately and independently, with an equal 1 in 2 chance of the child being female, the combined probability of a child being both female AND having sickle cell trait is 1/2 (probability of trait) multiplied by 1/2 (probability of female), which equals 1/4.

Persons 7 and 8 in Figure 4 are expecting a fourth child. Determine the probability that the child will have MSUD.

Since persons 7 and 8 are both unaffected but have already had a child with MSUD, a recessive condition, they must both be heterozygous carriers, Nn, giving gametes of N and n from each parent. Crossing the gametes N and n from person 7 with N and n from person 8 in a Punnett square gives four offspring genotypes: NN, Nn, Nn and nn. The genotype nn is the only one that has MSUD, since the condition is recessive, so one out of the four possible offspring, or a quarter, would be expected to have MSUD.

Show how the woman's parents could have a child that does not produce FSH.

Since the woman does not produce FSH, and this is recessive, she must be homozygous recessive, hh. As stated in the question, she inherited one faulty allele from each parent, so both of her parents must carry at least one copy of the h allele, meaning both are heterozygous, Hh, giving gametes of H and h from each parent. Crossing gametes H and h from one parent with H and h from the other parent in a Punnett square gives four offspring genotype combinations: HH, Hh, Hh and hh. The genotypes HH and Hh both produce FSH, since H is dominant, while the genotype hh does not produce FSH. This shows that even though both parents themselves produce FSH, there is a 1 in 4 chance of a child not producing FSH, exactly matching the woman's own situation described in the question.

AQA GCSE Biology Paper 2, Higher Tier: Ecology, Genetics and Evolution, Homeostasis and Response: every question, answered

6-mark extended response6 marksAO1, point marked with a two level mark scheme

“Describe how microorganisms break down carbon and nitrogen compounds in dead material, and how the released substances are taken in and used again by living plants”

Two of the four sittings we analysed built a 6-mark question around exactly this structure: a picture of dead material decaying (a compost heap or fallen leaves), asking you to trace both the breakdown by microorganisms and the reuse of the released substances by a living plant. The mark scheme rewards scientifically accurate, detailed points over a long list of vague ones.

Every 6-mark extended response asked — find yours1 question · 2 full worked answers

1×asked

“Describe how microorganisms in the layers of soil help to recycle chemicals in the dead plants, and how the chemicals are used again by living plants.”

June 2021Decomposition and nutrient cycling in a compost heap Full worked answer inside

What it’s really asking

The real Q04 (6 marks) shows a compost heap with alternating layers of dead plant material and thin layers of soil, and wants a full account of how carbon and nitrogen compounds cycle from the dead plants back into living plants via the microorganisms in the soil.

Sitting:

What the sources actually showed — June 2021

Figure 7

A diagram of a compost heap, drawn in cross section, showing alternating layers of dead plant material and thin layers of soil built up on top of each other.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2021

Written to: 6/6 · full, accurate, detailed coverage of both the microorganism-decomposition/CO2 route and the mineral-ion/nitrate route

Microorganisms in the soil layers, bacteria and fungi, digest the dead plant material using enzymes, breaking down large molecules such as proteins and carbohydrates into smaller soluble molecules. These microorganisms then respire, which releases carbon dioxide as a waste product into the air around the compost heap.

Why this scoresThis covers the first part of the carbon strand at Level 2 detail: naming the decomposers, the enzyme-based mechanism of decay, and the specific gas released by their respiration, rather than a vague 'things rot' statement.

That carbon dioxide diffuses out of the compost heap and into the air, where it can be taken in through the stomata of a living plant's leaves. Inside the leaf, the carbon dioxide is used in photosynthesis, combining with water to make glucose, which the plant can convert into starch or cellulose for its cell walls.

Why this scoresThis closes the carbon loop: from decomposer respiration to a named entry point (stomata) to a named use (photosynthesis making glucose, then starch or cellulose), which is the specific detail the mark scheme rewards over 'the plant uses it'.

The digestion of proteins in the dead plant material also releases nitrogen compounds into the soil as mineral ions such as nitrate. These nitrate ions are absorbed by the roots of a living plant, using active transport since the concentration of nitrate is often higher inside the root hair cells than in the soil.

Why this scoresThis opens the second required strand, nitrogen, with the same level of named detail: the specific ion (nitrate) and the specific mechanism of uptake (active transport against a concentration gradient), which distinguishes Level 2 from a Level 1 answer that just says 'nitrogen is recycled'.

Once inside the plant, the nitrate ions are used to make amino acids, which are then built into proteins the plant needs for growth, and nitrate is also needed to make chlorophyll and DNA. This completes the recycling of nitrogen from the dead plant material back into a new generation of living plant tissue.

Why this scoresThis finishes the nitrogen strand with named end uses (amino acids, proteins, chlorophyll, DNA), giving the answer equal depth on both required strands, which the mark scheme's Level 2 descriptor explicitly asks for.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise decomposition and nutrient cycling questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the sources actually showed — June 2023

Question stem only

No diagram accompanies this variant; the question states directly that dead leaves contain carbon compounds and nitrogen compounds and asks how both are recycled and used by living trees.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2023

Written to: 6/6 · full, accurate account covering decay, CO2 release/uptake, photosynthetic carbon use, and the complete nitrate uptake/use pathway

The dead leaves are broken down by decomposers, bacteria and fungi, which digest the large carbon and nitrogen compounds in the leaf tissue using enzymes, turning them into smaller, soluble substances. As the decomposers respire to release energy from this digested material, they produce carbon dioxide as a waste product, which is released into the air.

Why this scoresThis directly answers the 'how the leaves are broken down' instruction the question stem asks for, naming both the decomposer type and the enzyme mechanism, and introduces the carbon strand's key gas.

This carbon dioxide is taken in by nearby living trees through the stomata on their leaves, by diffusion, and is used in photosynthesis to produce glucose. The tree can then convert this glucose into starch for storage or into cellulose to build new cell walls as it grows.

Why this scoresThis is the 'how substances are taken in and used' half of the question for the carbon strand, naming the entry route (stomata, diffusion) and two specific end products (starch, cellulose), which earns the detailed Level 2 credit.

The decay of proteins in the dead leaves also releases nitrate ions into the soil. These nitrate ions are absorbed into the tree's roots by active transport, since the nitrate concentration is often lower in the soil than inside the root hair cells.

Why this scoresThis begins the nitrogen strand with a named ion and a named transport mechanism against the concentration gradient, the second required half of a full mark answer according to the mark scheme's note that both strands must be covered.

The nitrate is then used by the tree to build amino acids, which are combined to make new proteins for growth and repair, and nitrate is also essential for producing chlorophyll and DNA in new cells. In this way, both the carbon and the nitrogen originally locked up in the dead leaves are returned to the living tree.

Why this scoresThis finishes the nitrogen strand with the same specificity as the carbon strand (amino acids, proteins, chlorophyll, DNA), giving the answer the balanced Level 2 depth the mark scheme's indicative content spells out for both compound types.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise decomposition and nutrient cycling questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Naming bacteria and/or fungi as the decomposers, not just 'microorganisms' unqualified
Linking decay to enzyme digestion turning large molecules into small ones
Naming carbon dioxide as the gas released by microorganism respiration and its route back into a plant via stomata, then into photosynthesis
Naming nitrate ions as the mineral released and active transport as the route back into roots, then into amino acids, proteins, DNA or chlorophyll

Evidence to deploy — 6 factsScreenshot this

Decomposers, bacteria and fungi, digest dead organic material using enzymes
Microorganism respiration releases carbon dioxide into the air
Plants take in carbon dioxide through stomata for photosynthesis, making glucose, starch and cellulose
Decay of proteins releases nitrate ions into the soil
Plant roots absorb nitrate ions by active transport against the concentration gradient
Nitrate is used to make amino acids, proteins, chlorophyll and DNA

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Only describing one half of the cycle (just carbon, or just nitrogen) when the question explicitly asks for both
Saying 'nutrients are recycled' without naming the specific substance (carbon dioxide, nitrate) or the specific process (respiration, active transport)
Forgetting to close the loop by saying what the living plant actually uses the substance for

Full-mark self-check 0 of 4

Have I covered both the carbon strand and the nitrogen strand with equal detail?Have I named the decomposers and the specific mechanism (enzymes, respiration)?Have I named the specific substance released (carbon dioxide, nitrate) and the specific route it takes back into a living plant?Have I named what the plant actually builds from that substance?

The method for every 6-mark extended response — same every sittingMark bands, steps, timing

What this question type rewards

The topic changes by sitting — the mark scheme never does. Learn this once, then open your question above for that sitting’s sources and a full worked answer.

Naming the decomposers (bacteria and/or fungi) and the process of decay by digestion or enzyme action
Explaining that respiration by microorganisms releases carbon dioxide, which is then taken up by living plants through stomata for photosynthesis
Explaining that decay releases mineral ions such as nitrate, which is taken up by roots (by active transport) and used to build amino acids, proteins, DNA or chlorophyll
Covering BOTH the carbon strand and the nitrogen strand in detail, not just one of them

Level 2, 4 to 6 marksScientifically relevant facts, events or processes are identified and given in detail to form an accurate account.

Level 1, 1 to 3 marksFacts, events or processes are identified and simply stated but their relevance is not clear.

The steps

Split your answer into two clear halves: what happens to carbon compounds, and what happens to nitrogen compounds
For each half, name the microorganisms and the process (decay, respiration, digestion by enzymes)
Name the specific substance released (carbon dioxide for the carbon strand, nitrate ions for the nitrogen strand)
Explain how the living plant takes that substance back in and what it is used for (photosynthesis and making glucose or starch for carbon dioxide, making amino acids or proteins or DNA for nitrate)

6 marks, worth about 6 to 7 minutes of the paper. Do not run out of things to say for one half of the cycle

Try one now — from our question bank

Which organisms are the main decomposers?

This question always splits into a carbon half and a nitrogen half, and marks are lost for only doing one properly. Practise naming the exact gas, ion and process at every step.

Practise decomposition and nutrient cycling questions

3-mark evidence question3 marksAO2/AO3, point marked

“Explain what happened to the growth of a seedling shoot in one-sided light, or describe evidence that supports a hypothesis about how auxin moves or behaves”

Every sitting we analysed with a plant hormone question builds it around a real shoot-tip or agar-block experiment, then asks you to interpret what the data show about auxin's role in phototropism. The specific numbers and hypothesis change, but the skill tested is always reading experimental evidence, not reciting a textbook definition.

Every 3-mark evidence question asked — find yours2 questions · 2 full worked answers

1×asked

“Explain what happened to the growth of the seedling on side Q compared with the growth on side P.”

June 2020Phototropism and unequal auxin distribution in a curved seedling Full worked answer inside

What it’s really asking

The real Q03.4 (3 marks) shows a seedling growing towards a lamp with the shoot curved, side P nearest the lamp and side Q furthest away, and wants an explanation of why side Q grew more than side P.

What the sources actually showed — June 2020

Figure 4

A diagram of a lamp positioned to one side of a growing seedling, with the shoot shown curving towards the lamp. Side P is labelled as the side of the shoot nearest the lamp, and side Q as the side furthest from the lamp.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2020

Written to: 3/3 · Full marks, links unequal auxin to unequal cell elongation and to the curvature

Side Q, the side furthest from the lamp, received less light than side P, so more auxin built up on side Q because auxin moves towards the shaded side of the shoot. This higher concentration of auxin on side Q caused the cells there to elongate more than the cells on side P.

Why this scoresThis directly names which side has more auxin (Q, the shaded side) and states the mechanism of unequal distribution, which is the first mark point the scheme rewards.

Because side Q grew more than side P, the shoot bent towards the lamp, since the shorter, less-elongated side P effectively pulled that side of the shoot towards the light source.

Why this scoresThis closes the answer by linking the unequal growth directly to the visible curvature described in the source, which is the comparative conclusion the question specifically asks for.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise plant hormone and phototropism questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Correctly identifying that the shaded side (side Q) had more auxin
Linking more auxin to more cell elongation on that side
Concluding this unequal growth caused the shoot to bend towards the light

Evidence to deploy — 4 factsScreenshot this

Auxin is produced in the tip of a shoot and moves down towards the growing region
Auxin moves to the shaded side of a shoot when light is one sided
Higher auxin concentration causes greater cell elongation
Unequal cell elongation on the two sides of a shoot causes it to bend

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Saying 'more auxin on side Q' without saying which side is shaded, since a marker cannot tell if a candidate has confused P and Q
Describing the bending without explaining the underlying cause (unequal auxin, unequal cell elongation)

Full-mark self-check 0 of 3

Have I named which side has more auxin and why (it is the shaded side)?Have I linked more auxin to more cell elongation?Have I explained that this unequal growth is what causes the bending?

1×asked

“Describe the evidence from Figure 14 which supports the hypothesis that light causes auxin to move from the side of the shoot nearest the light to the side furthest from the light.”

June 2022Auxin diffusion in agar blocks under one-sided light Full worked answer inside

What it’s really asking

The real Q09.5 (3 marks) shows four shoot tips placed on agar blocks under different lighting conditions, with numbers showing the mass of auxin that diffused into each block, and wants you to pick out which numbers support the stated hypothesis.

What the sources actually showed — June 2022

Figure 14

Four separate shoot-tip experiments (labelled D, E, F and G) each with a shoot tip placed on a small block of agar jelly. Two are kept in the dark and two receive one-sided light, with numbers given under each block showing the mass of auxin, in arbitrary units, that diffused into that block, split by side for the blocks that were cut in half with a thin strip of glass down the middle.

Experiment	Condition	Auxin diffused — left half, units	Auxin diffused — right half, units
D	Kept in the dark (block not split)	25.3	not split
E	Kept in the dark (split by glass)	12.5	12.4
F	One-sided light from the right (split by glass)	17.2	7.8
G	One-sided light from the right (split by glass)	12.6	12.6

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2022

Written to: 3/3 · Full marks, cites both the dark control and the one-sided light block by their actual numbers

In experiment E, which was kept in the dark with a glass barrier splitting the agar block into two halves, the mass of auxin was almost equal in both halves (12.5 and 12.4 units), showing that without one-sided light, auxin diffuses evenly to both sides of the shoot.

Why this scoresThis establishes the baseline from the dark control, using the actual near-equal numbers from the source, which the mark scheme credits as part of the comparative evidence needed.

In experiment F, which had one-sided light and the same glass barrier, the mass of auxin was much higher on the side furthest from the light (17.2 units) than on the side nearest the light (7.8 units). This uneven split only appeared when light was one sided, which supports the hypothesis that light causes auxin to move away from the light towards the shaded side.

Why this scoresThis is the direct evidence for the hypothesis, using the real, specific values from experiment F and explicitly contrasting them with the even split from the dark control in experiment E, which is exactly the comparative reasoning the mark scheme rewards.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise plant hormone and phototropism questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Referring to the roughly equal auxin split in the dark control block
Referring to the unequal auxin split in the one-sided light block, specifically more auxin on the shaded side
Making clear the comparison between the two situations supports the hypothesis

Evidence to deploy — 4 factsScreenshot this

Auxin diffuses from a cut shoot tip into an agar block below it
A glass barrier prevents auxin moving sideways within the block, so it can be measured separately on each side
In the dark, auxin distributes evenly since there is no light-driven signal to move it to one side
Under one-sided light, more auxin accumulates on the shaded side than the illuminated side

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Quoting the wrong experiment letter or wrong numbers, always double check which block was in the dark and which had one-sided light
Describing only the one-sided light result without contrasting it with the dark control, since the comparison is the actual evidence for the hypothesis

Full-mark self-check 0 of 3

Have I quoted the near-equal numbers from the dark control?Have I quoted the unequal numbers from the one-sided light experiment, and identified which side is which?Have I explicitly stated that this contrast supports the hypothesis?

The method for every 3-mark evidence question — same every sittingMark bands, steps, timing

What this question type rewards

The topic changes by sitting — the mark scheme never does. Learn this once, then open your question above for that sitting’s sources and a full worked answer.

Correctly identifying which side of the shoot has more auxin, and linking this to which side grows more
Referring to specific numbers or specific parts of the described diagram, not a general statement
Explaining the mechanism: auxin causes cell elongation on the side with more of it, causing the shoot to bend

Full marks (3 marks)Explains growth and bending together, refers to specific evidence from the source material, and correctly attributes the mechanism to auxin distribution.

Partial marks (1 to 2 marks)Identifies unequal growth or unequal auxin distribution but does not link both together, or omits reference to the mechanism (cell elongation).

The steps

Identify which side of the shoot received less light (the shaded side)
State that side has more auxin, because auxin moves away from the light
State that more auxin means more cell elongation, so that side grows more
Conclude that the shoot bends towards the light because the shaded side has grown longer

3 marks, about 4 minutes. Keep the answer tightly linked to the actual described evidence

Try one now — from our question bank

When a plant shoot is lit from one side, where does auxin accumulate?

This question is always about reading real numbers from an auxin experiment, not reciting the theory from memory. Practise picking out the exact comparison the data shows.

Practise plant hormone and phototropism questions

2 to 3-mark mechanism explanation2 marksAO2, point marked

“Explain why a specific body change (decreased body temperature, dilated blood vessels) happens during temperature regulation”

Both sittings we analysed with a temperature regulation question isolate one specific mechanism, either why drinking something cold changes internal body temperature, or why dilating blood vessels helps to cool the body down, and ask for a mechanistic chain rather than a one-line fact.

Every 2 to 3-mark mechanism explanation asked — find yours2 questions · 2 full worked answers

1×asked

“The results show that when the ice-cold water was drunk, the temperature near the brain decreased. Explain why the temperature near the brain decreased.”

June 2021How drinking ice-cold water cools internal body temperature Full worked answer inside

What it’s really asking

The real Q03.3 (2 marks) follows a graph showing a person's internal body temperature dipping sharply after drinking 500cm³ of ice-cold water, and wants the physical explanation for why that measured drop near the brain happens.

What the sources actually showed — June 2021

Figure 5

A line graph of internal body temperature in degrees Celsius over 70 minutes, showing a steady 37.4 degrees Celsius baseline that dips sharply to around 36.8 degrees Celsius shortly after the point marked 'drinks ice-cold water', then rises back to baseline.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2021

Written to: 2/2 · Full marks, links cooling at the mouth or stomach to the measured temperature drop near the brain

The blood is cooled as it passes close to the ice-cold water in the stomach and mouth, since heat is transferred from the warmer blood into the colder water. This cooled blood then circulates around the body and flows to the brain, lowering the temperature measured there.

Why this scoresThis gives both required steps: WHERE the cooling physically happens (stomach and mouth, by heat transfer to the cold water) and HOW that cooled blood reaches the measurement site near the brain, which is exactly the two-step chain the mark scheme rewards.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise temperature regulation questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Stating that blood is cooled at the stomach or mouth by contact with the cold water
Stating that this cooled blood then flows to the brain, explaining the measured drop

Evidence to deploy — 3 factsScreenshot this

Drinking cold water directly cools blood passing near the mouth and stomach
Blood circulates around the whole body carrying heat or cold with it
The thermoregulatory centre in the brain (hypothalamus) monitors blood temperature

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Only saying 'the water is cold so the body gets cold' without mentioning the blood as the carrier of temperature change
Confusing this with the skin's response to external cold, when the question is specifically about internal temperature measured near the brain

Full-mark self-check 0 of 2

Have I said where the blood is directly cooled (mouth or stomach)?Have I said that this cooled blood then reaches the brain, explaining the measured drop?

1×asked

“An echidna can dilate and constrict blood vessels in its skin. Explain how the dilation of blood vessels in the skin can help to decrease body temperature.”

June 2022Vasodilation and heat loss in a hibernating mammal Full worked answer inside

What it’s really asking

The real Q08.4 (3 marks) is about an echidna waking from hibernation with a body temperature over 30 degrees Celsius, and wants an explanation of how dilating skin blood vessels specifically brings that temperature back down.

What the sources actually showed — June 2022

Question context only

The stem states the echidna's body temperature rises above 30 degrees Celsius each time it wakes from hibernation, and that it can dilate or constrict blood vessels in its skin, without an accompanying diagram.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2022

Written to: 3/3 · Full marks, gives the full chain from vessel diameter to heat loss to cooler blood

More blood flows nearer to the surface of the skin when the blood vessels there dilate, because the wider vessels allow a greater volume of blood to pass close to the skin's surface. This means more heat is able to transfer from the blood to the surrounding air, since heat can escape more easily the closer the blood is to the surface.

Why this scoresThis gives the mechanical first step (dilation lets more blood flow near the surface) and the physical consequence (more heat transferred to the air), which the mark scheme separates as its first two credit points.

As heat is lost from this blood to the environment, the blood itself becomes cooler, and this cooler blood then circulates back around the echidna's body, lowering its overall body temperature.

Why this scoresThis closes the chain with the final step the mark scheme wants: the blood that lost heat then cools the whole body once it recirculates, rather than stopping at 'heat is lost' without explaining how that lowers body temperature overall.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise temperature regulation questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Stating that dilation moves more blood flow near the skin surface
Stating that this causes more heat to be lost from the blood to the surroundings
Stating that this cools the blood, which then circulates and cools the whole body

Evidence to deploy — 3 factsScreenshot this

Blood vessels near the skin surface can dilate (widen) or constrict (narrow)
Dilation increases blood flow near the surface where heat can radiate away
Cooled blood recirculates around the body, lowering overall body temperature

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Stopping at 'heat is lost' without explaining that this cools the blood which then cools the whole body
Confusing dilation (widening, increases heat loss) with constriction (narrowing, reduces heat loss)

Full-mark self-check 0 of 3

Have I explained that dilation moves more blood near the surface?Have I explained that this increases heat loss to the surroundings?Have I closed the loop by saying the cooled blood then lowers overall body temperature?

The method for every 2 to 3-mark mechanism explanation — same every sittingMark bands, steps, timing

What this question type rewards

The topic changes by sitting — the mark scheme never does. Learn this once, then open your question above for that sitting’s sources and a full worked answer.

Naming the specific physical process involved (cooling of blood, heat loss from blood vessels near the surface)
Linking cause to effect in a clear chain, not just stating the end result

Full marks (2 marks)Both linked steps of the mechanism are stated clearly and in the correct order.

Partial marks (1 mark)Only one step of the mechanism, or the correct idea but expressed too vaguely to be sure it is right.

The steps

Identify exactly which mechanism the question is asking about (do not confuse vasodilation with vasoconstriction)
State the direct physical effect (blood is cooled, or blood flows nearer the skin surface)
State the resulting change in body temperature and explain why

2 to 3 marks, about 3 minutes. Keep the chain short and specific rather than padding with general homeostasis facts

Try one now — from our question bank

What is the normal core body temperature in humans?

This question always wants a short, specific mechanism chain rather than a general homeostasis fact. Practise linking each step clearly.

Practise temperature regulation questions

3-mark effect and explanation3 marksAO1/AO2, point marked

“Explain the effect a high concentration of insulin has on blood glucose concentration, or explain negative feedback control of a named substance”

Both sittings we analysed test the same underlying skill, negative feedback, but from two different angles: one gives you a real blood glucose graph and asks for insulin's specific effect, the other gives a generic negative feedback diagram with two hormones and asks you to explain the whole loop using the diagram's own labels.

Every 3-mark effect and explanation asked — find yours2 questions · 2 full worked answers

1×asked

“Explain the effect a high concentration of insulin has on blood glucose concentration.”

June 2022Insulin's effect on blood glucose after a meal Full worked answer inside

What it’s really asking

The real Q03.2 (3 marks) follows a graph of blood glucose concentration rising sharply after a meal and then falling back to baseline within about two hours, and wants the effect of insulin plus the mechanism by which it lowers glucose.

What the sources actually showed — June 2022

Figure 2

A line graph of blood glucose concentration in mmol per cubic decimetre over 4 hours, starting around 4.4, rising to a peak of about 6.0 roughly 90 minutes after a meal is eaten, then falling back down to around 4.4 by 2.5 hours and staying level.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2022

Written to: 3/3 · Full marks, effect plus mechanism plus location

A high concentration of insulin lowers blood glucose concentration. This happens because insulin causes glucose to be taken into cells, and it also causes the liver and muscles to convert excess glucose into glycogen for storage.

Why this scoresThis gives the direct effect (lowered) plus the specific mechanism (uptake into cells, conversion to glycogen), both of which are separately creditable mark points rather than combining into one vague sentence.

These processes are carried out by cells throughout the body, but the liver and muscle cells in particular store the excess glucose as glycogen, which explains why blood glucose concentration falls back towards its normal level within around two hours of the meal.

Why this scoresThis names the location (liver, muscles) required for the third mark point and connects it back to the actual shape of the graph, showing the answer is grounded in the real data rather than generic textbook recall.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise glucose regulation and negative feedback questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Stating the effect is lowered blood glucose concentration
Stating the mechanism: glucose taken in, or converted to glycogen
Naming the cells or organs involved (cells generally, or liver, or muscles)

Evidence to deploy — 3 factsScreenshot this

Insulin is released by the pancreas when blood glucose is high
Insulin causes body cells to take up glucose from the blood
Insulin causes the liver and muscles to convert glucose into glycogen for storage

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Saying insulin 'controls' blood glucose without stating the direction (lowered) or the mechanism
Confusing insulin's effect with glucagon's opposite effect

Full-mark self-check 0 of 3

Have I stated the effect is a decrease in blood glucose concentration?Have I named the mechanism (uptake into cells, or conversion to glycogen)?Have I named where this happens (liver or muscle cells)?

1×asked

“Explain how the concentration of substance Q in the blood is controlled by negative feedback.”

June 2023General negative feedback loop for a hormone-controlled substance Full worked answer inside

What it’s really asking

The real Q05.1 (3 marks) shows a generic negative feedback diagram with an ideal concentration of a substance Q, and arrows showing hormone A released if Q rises too high and hormone B released if Q falls too low, and wants the whole loop explained using the diagram's own labels.

What the sources actually showed — June 2023

Figure 8

A generic negative feedback diagram with a central box showing 'ideal concentration of substance Q', with an arrow labelled 'increase of substance Q' leading up to a box 'concentration of substance Q too high', which has an arrow labelled 'hormone A' pointing back down to the ideal box. A mirrored arrow labelled 'decrease of substance Q' leads down to a box 'concentration of substance Q too low', which has an arrow labelled 'hormone B' pointing back up to the ideal box.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2023

Written to: 3/3 · Full marks, explains both directions of the loop using the diagram's own labels

If the concentration of substance Q becomes too high, hormone A is released and used to bring the concentration back down towards the ideal level.

Why this scoresThis directly uses the diagram's own labels (substance Q, hormone A) to explain the 'too high' half of the loop, which the mark scheme credits explicitly since the question could equally be answered in terms of insulin/glucagon for blood glucose.

If the concentration of substance Q becomes too low, hormone B is released and used to bring the concentration back up towards the ideal level.

Why this scoresThis mirrors the first paragraph for the opposite direction, since a negative feedback answer is not complete unless both directions of the loop are explained, matching the second creditable mark point.

In both cases the released hormone acts to bring substance Q's concentration back to its ideal, normal level, which is the defining feature of a negative feedback system.

Why this scoresThis closes with the general principle the mark scheme's third point wants: that the whole system works to restore the ideal concentration, tying the two directional halves together into one coherent negative feedback explanation.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise glucose regulation and negative feedback questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Explaining that a high concentration triggers hormone A, which lowers it back to ideal
Explaining that a low concentration triggers hormone B, which raises it back to ideal
Stating that the overall effect of the hormones is to restore the ideal concentration

Evidence to deploy — 4 factsScreenshot this

Negative feedback systems detect a change away from an ideal/normal level
A hormone is released that counteracts the direction of change
The system continues to adjust until the level returns to ideal
This same negative feedback pattern controls blood glucose (insulin and glucagon), blood water content (ADH), and body temperature (thyroxine)

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Only explaining one direction of the loop (just 'too high') when the question and diagram clearly show both directions need covering
Not using the diagram's own labels (substance Q, hormone A, hormone B) and instead writing a generic answer that does not engage with the specific source

Full-mark self-check 0 of 3

Have I explained the 'too high' direction using hormone A?Have I explained the 'too low' direction using hormone B?Have I stated that both responses aim to restore the ideal concentration?

The method for every 3-mark effect and explanation — same every sittingMark bands, steps, timing

What this question type rewards

The topic changes by sitting — the mark scheme never does. Learn this once, then open your question above for that sitting’s sources and a full worked answer.

Stating the correct direction of effect (insulin lowers blood glucose, not raises it)
Naming the actual biological mechanism (glucose taken into cells, or converted to glycogen) rather than just the outcome
For negative feedback questions, correctly using both directions (too high triggers one hormone, too low triggers the other) and explaining that the response returns the level to normal

Full marks (3 marks)Effect, mechanism and location (or, for negative feedback, both directions of the loop) are all stated correctly.

Partial marks (1 to 2 marks)The correct direction of effect is given but the mechanism or location is missing or vague, or only one direction of the feedback loop is explained.

The steps

State whether the level goes up or down as a result of the hormone described
State the specific cellular mechanism causing that change
Name where in the body this happens if the question or diagram supports it
For negative feedback questions, explicitly state that the response returns the level back towards normal/ideal

3 to 4 marks, about 4 minutes

Try one now — from our question bank

Which organ monitors blood glucose concentration and secretes insulin and glucagon?

Negative feedback questions always want both directions of the loop and the specific mechanism, not just 'a hormone fixes it'. Practise stating the full chain.

Practise glucose regulation and negative feedback questions

4 to 5-mark Punnett square5 marksAO2/AO3, point marked

“Draw a Punnett square diagram, identify the phenotype of each offspring genotype, and give the probability of a named outcome”

This is one of the most reliable questions on the whole paper. All four sittings we analysed include a real family pedigree or genetics scenario followed by a Punnett square question worth 4 or 5 marks, always rewarding the same sequence: correct gametes, correct offspring genotypes, correct phenotypes, and a correct final probability.

The method for every 4 to 5-mark Punnett square — same every sittingMark bands, steps, timing

What this question type rewards

The topic changes by sitting — the mark scheme never does. Learn this once, then open your question above for that sitting’s sources and a full worked answer.

Correctly writing the two possible gametes from each parent using the given allele symbols
Correctly deriving all four offspring genotype combinations in a Punnett square grid
Correctly stating the phenotype (has the condition, or does not, or is a carrier) for each genotype
Giving the final probability as a fraction, decimal or percentage consistent with the square drawn

Full marks (4 to 5 marks, depending on sitting)All four steps, gametes, genotypes, phenotypes and probability, are present and internally consistent, even if an earlier step contains an error that is carried through correctly.

Partial marksSome steps present but with errors, or the final probability inconsistent with the student's own derived genotypes.

The steps

Write out both parents' genotypes using the symbols given in the question
Split each parent's genotype into the two possible gametes
Draw a 2x2 grid and fill in all four combinations by crossing each parent's gametes
State the phenotype for each of the four genotype combinations
State the probability of the specific outcome asked for, as a fraction, decimal or percentage

4 to 5 marks, about 5 to 6 minutes including drawing the grid

Try one now — from our question bank

What is the term for an allele that is always expressed when present?

Punnett square questions always reward the full chain: gametes, genotypes, phenotypes, then probability. Practise every step, not just the final fraction.

Practise genetic inheritance and Punnett square questions

6-mark extended response6 marksAO1/AO2, point marked or level marked depending on sitting

“Explain how a population evolved a new trait through natural selection, or explain how fossil evidence and genetics have both shaped our understanding of evolution”

Two of the four sittings we analysed build a high-tariff evolution question, one following a single population through a specific mutation and natural selection (birds evolving UV vision), the other asking more broadly how two different strands of evidence, fossils and genetics, have together developed our understanding of evolution since Darwin.

Every 6-mark extended response asked — find yours2 questions · 2 full worked answers

1×asked

“Explain how birds that detect UV light have evolved from birds that could not detect UV light.”

June 2020Natural selection of a new sensory mutation (UV vision in birds) Full worked answer inside

What it’s really asking

The real Q06.5 (6 marks) states that some birds' eyes contain cells that detect ultraviolet light, that UV light is reflected by some fruits and by the urine of small mammals, and wants the full natural selection story for how this trait spread through a bird population.

What the sources actually showed — June 2020

Question context only

The stem states that the eyes of some birds contain cells that detect ultraviolet light, and that UV light is reflected by some fruits and by the urine of small mammals, with no accompanying diagram.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2020

Written to: Level 3 · 6/6full logical chain (mutation, UV-linked advantage, survival, inheritance, natural selection) hits the mandatory link-to-UV-vision gate for Level 3

A random mutation occurred in the gene for a visual pigment in the retina of a bird, by chance, causing that bird's retina to produce a slightly different pigment able to detect a wider range of wavelengths of light, including ultraviolet.

Why this scoresThis opens with the origin of the variation, naming it as a random mutation causing a new protein/pigment, which the mark scheme's indicative content lists as the essential starting point of the chain.

Birds with this mutation could detect ultraviolet light, so they were more likely to see fruits that reflect UV light, and more likely to see the urine trails of small mammals, which also reflects UV light, helping them locate prey.

Why this scoresThis links the new trait directly to the two specific advantages named in the question's own context (fruit, small mammal urine), which is the specific, source-grounded reasoning the mark scheme rewards over a generic 'they could see better' statement.

Because they could find more food, birds with the UV-detecting mutation were more likely to survive and reproduce than birds without the mutation, outcompeting them for the same limited food sources.

Why this scoresThis is the survival-and-reproduction step of the chain, explicitly stating the competitive advantage over non-mutated birds, which the mark scheme's indicative content separates out as its own creditable point.

These surviving birds passed the mutated allele on to their offspring, and over many generations, more and more birds in the population inherited the ability to detect UV light, until eventually most or all birds in that population had evolved this trait by natural selection.

Why this scoresThis closes the chain with inheritance and repetition over many generations, the final step the mark scheme requires for a Level 3 answer, and explicitly names natural selection as the mechanism.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise evolution and natural selection questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Starting the chain with a random mutation affecting the retina's visual pigment
Linking the new trait specifically to seeing UV-reflecting fruits and UV-reflecting small mammal urine (the two clues given in the question)
Explaining the survival and reproductive advantage this trait gives over birds without it
Explaining inheritance of the allele and repetition over many generations as the mechanism of natural selection

Evidence to deploy — 4 factsScreenshot this

Mutations occur randomly and can create new versions of a gene or protein
Some fruits and the urine of small mammals reflect ultraviolet light
Natural selection favours individuals with an advantageous trait for survival and reproduction
An advantageous allele becomes more common in a population over many generations

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Writing a generic natural selection answer without linking each step specifically to UV detection and the two named UV-reflecting sources in the question
Skipping the mutation origin step and starting from 'some birds could see UV', missing the first mark point

Full-mark self-check 0 of 4

Have I started with a random mutation as the origin of the new trait?Have I linked the trait specifically to seeing UV-reflecting fruit and small mammal urine?Have I explained the survival and reproductive advantage this gives?Have I explained that this trait spreads through the population over many generations?

1×asked

“Explain how our understanding of evolution has developed due to: fossil evidence, and increased understanding of the mechanisms of genetics.”

June 2023Development of evolutionary theory through fossil evidence and genetics Full worked answer inside

What it’s really asking

The real Q09 (6 marks) explicitly names two separate strands, fossil evidence and genetics, and requires both to be covered in detail for the top level, since a Level 3 answer specifically needs both parts addressed.

What the sources actually showed — June 2023

Question context only

The stem states that a wide variety of species exists on Earth and that most scientists accept Darwin's theory of evolution by natural selection as the explanation for this, with no accompanying diagram.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2023

Written to: Level 3 · 6/6full marks, covers both required strands (fossils and genetics) in detail, includes a named worked example and closes the loop to speciation

Fossils give us direct evidence of organisms that lived in the past, showing how species have changed over time and providing evidence of species that have since become extinct. By comparing fossils of different ages, scientists can build evolutionary trees showing how organisms alive today are related to earlier species.

Why this scoresSecures the fossil evidence marking points: fossils show evidence of life in the past, show change over time, show evidence of extinction, and the fossil record shows how species alive today are related to earlier organisms (via evolutionary trees).

There are still gaps in the fossil record because the conditions needed for a fossil to form are rare, so not every organism that has ever lived has left a trace. However, new fossil discoveries keep being made, and these help fill in some of the gaps, giving a clearer picture of exactly how and when different species diverged from one another.

Why this scoresCovers the mark scheme points on gaps in the fossil record and gaps being filled in with new evidence.

Separately, our understanding of genetics has also developed. Mendel's breeding experiments with pea plants first suggested that characteristics are passed on as separate units, which we now know as genes or alleles, occurring in dominant and recessive forms. Later, scientists observed chromosome behaviour during cell division and found that it matched the pattern Mendel had already worked out mathematically. Eventually the structure of DNA was discovered, and the mechanism by which genes control protein production was worked out too.

Why this scoresSecures all six genetics-development marking points in sequence: Mendel's breeding experiments, his idea of units of inheritance, dominant/recessive alleles, chromosome behaviour during cell division matching Mendel's pattern, structure of DNA worked out, and gene mechanism in protein synthesis worked out.

This understanding of genetics explains where variation within a species comes from, since a mutation can change the structure of a gene. If that mutation gives an individual an advantageous characteristic, that individual is more likely to survive in its environment. Because it survives, it is also more likely to reproduce, and when it does, it passes on the advantageous allele to its offspring, so the allele becomes more common in the population over generations.

Why this scoresSecures variation due to mutation, individuals with advantageous characteristics more likely to survive, more likely to reproduce, and survivors specifically passing on the advantageous allele/gene to offspring, kept as distinct steps rather than compressed together.

A real example of this is antibiotic resistance in bacteria. A random mutation can make a bacterium resistant to an antibiotic; when the population is exposed to that antibiotic, the resistant bacterium survives and reproduces while non-resistant bacteria are killed, so the resistance allele spreads through the population. More generally, if enough genetic change accumulates in a population over time, it can become so different from the original population that it can no longer successfully reproduce with it, which is how a new species can eventually arise.

Why this scoresProvides the named example of evolution (antibiotic resistance in bacteria) and closes the loop by linking accumulated genetic change to new species arising when successful reproduction with the original population is no longer possible.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise evolution and natural selection questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Detail on fossil evidence: showing change over time, evidence of extinction, evolutionary trees, and acknowledgement of gaps being filled by new discoveries
Detail on genetics: Mendel's original experiments, chromosome behaviour matching his units, discovery of DNA structure and gene mechanism
Explicitly covering BOTH strands with real detail, since the mark scheme states Level 3 requires detail on fossils AND genetics

Evidence to deploy — 6 factsScreenshot this

Fossils show gradual change in organisms over long periods of time and evidence of extinction
The fossil record has gaps because fossilisation requires specific rare conditions
Mendel's pea plant experiments first suggested inheritance occurs via discrete dominant and recessive units
Chromosome behaviour during cell division was later found to match Mendel's units
The structure of DNA and the gene mechanism for protein synthesis were worked out afterwards
Mutation creates genetic variation, and natural selection favours individuals with advantageous variation

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Writing six marks worth of detail on only one strand (for example, all fossils, no genetics), which caps the answer well below Level 3 according to the mark scheme's explicit requirement for both
Describing modern genetics facts without connecting them back to how they developed OUR UNDERSTANDING of evolution specifically, rather than just restating genetics facts

Full-mark self-check 0 of 3

Have I given detailed, specific content on fossil evidence, not just one line?Have I given detailed, specific content on genetics, not just one line?Have I linked both strands together in my conclusion, showing they combine to explain evolution?

The method for every 6-mark extended response — same every sittingMark bands, steps, timing

What this question type rewards

The topic changes by sitting — the mark scheme never does. Learn this once, then open your question above for that sitting’s sources and a full worked answer.

For the natural selection variant: correctly sequencing mutation, then variation, then survival advantage, then reproduction, then repeated over generations
For the broader evolution variant: covering BOTH named strands (fossil evidence and genetics) with real, specific detail rather than one strand only
Linking cause and effect logically so an examiner can follow the chain of reasoning from start to finish

Level 3, 5 to 6 marksRelevant points are identified, given in detail, and logically linked to form a clear account, covering all parts the question asks for.

Level 2, 3 to 4 marksRelevant points are identified with some logical linking attempted, but the account is not fully clear or misses depth on one required strand.

Level 1, 1 to 2 marksPoints are identified and stated simply, but their relevance is not clear and there is no attempt at logical linking.

The steps

Identify how many separate strands the question asks for (one trait's evolution, or two evidence types) and make sure you cover all of them
Start with the origin of variation (mutation, or Mendel's original experiments)
Trace the mechanism step by step: advantage, survival, reproduction, inheritance, repetition over generations
Finish with a clear statement of the overall outcome (a new characteristic spreads through the population, or our understanding of evolution becomes more complete)

6 marks, about 7 to 8 minutes. This is one of the longest point-scoring opportunities on the paper, so plan before writing

Try one now — from our question bank

What is evolution?

This question either wants a full natural selection chain for one specific trait, or detailed coverage of every strand named in the question. Missing depth on one part caps your mark well below full marks.

Practise evolution and natural selection questions

6-mark extended response6 marksAO2, point marked

“Describe how the nervous system coordinates a reflex action from stimulus to response”

The reflex arc question always asks you to trace the full pathway from stimulus through to muscle response, naming each part of the nervous system in the correct order. Marks are lost for skipping a stage or naming the parts out of sequence.

Every 6-mark extended response asked — find yours1 question · 1 full worked answer

1×asked

“A woman's hand accidentally touches a hot object. The woman moves her hand away rapidly. Describe how the woman's nervous system coordinates the reflex action.”

June 2021Reflex arc pathway for withdrawing a hand from a hot object Full worked answer inside

What it’s really asking

The real Q06.2 (6 marks) gives a specific real-life scenario, a hand touching something hot and being pulled away, and wants the full nervous system pathway that coordinates that automatic, rapid response.

What the sources actually showed — June 2021

Question context only

The stem describes a woman's hand accidentally touching a hot object and the hand being moved away rapidly, with no accompanying diagram.

The real data and numbers, recreated in our own layout — never the exam board's own artwork or photos.

The full worked answer — June 2021

Written to: 6/6 · Full marks, every stage of the reflex arc named in the correct order

A receptor in the skin of the woman's finger or hand detects the temperature change caused by touching the hot object, and this triggers an electrical impulse that passes along a sensory neurone towards the spinal cord.

Why this scoresThis opens with the receptor and the specific stimulus (temperature change) named, and correctly starts the impulse along the sensory neurone, matching the first stages the mark scheme's indicative content lists.

At a synapse in the spinal cord, the impulse passes from the sensory neurone to a relay neurone. This happens because a chemical (a neurotransmitter) is released across the gap between the two neurones, triggering a new electrical impulse in the relay neurone.

Why this scoresThis correctly names the synapse and its chemical mechanism, which the mark scheme requires as a distinct creditable point, not just 'the message passes to the next neurone'.

The impulse then passes along the relay neurone, which is located entirely within the spinal cord, and across a second synapse to a motor neurone, again using a neurotransmitter to cross this gap.

Why this scoresThis correctly places the relay neurone within the spinal cord/CNS and repeats the synapse mechanism for the second synapse, which the mark scheme also credits, showing the answer understands synapses occur at both neurone junctions.

The impulse travels along the motor neurone to a muscle in the woman's arm, which is the effector. The muscle contracts, pulling the hand away from the hot object rapidly, without the woman needing to consciously think about the action.

Why this scoresThis correctly names the effector (a muscle) and the resulting response (contraction, pulling the hand away), and closes with the defining feature of a reflex, that it happens automatically without conscious thought, which the mark scheme's context rewards as the final linking point.

Could you have written this? Every fact in this answer is drilled in our quizzes — the writing is the easy part once the evidence is automatic.

Practise reflex arc questions

Worked answer · PrepWise · prepwise.ukOur own writing — aimed at the real mark scheme, never copied

What the mark scheme rewarded

Naming the receptor and the specific stimulus (temperature/heat) it detects
Correctly sequencing sensory neurone, then a synapse, then relay neurone (in the spinal cord), then a second synapse, then motor neurone
Naming the synapse mechanism as a chemical/neurotransmitter crossing the gap between neurones
Naming the effector as a muscle and describing muscle contraction as the response

Evidence to deploy — 6 factsScreenshot this

Receptors detect specific stimuli and convert them into electrical impulses
Sensory neurones carry impulses from receptors towards the central nervous system
Relay neurones are located within the spinal cord or brain and connect sensory to motor neurones
Synapses are gaps between neurones crossed using a chemical neurotransmitter
Motor neurones carry impulses to effectors (muscles or glands)
Reflexes are automatic and rapid because they do not involve conscious processing by the brain

PrepWise · prepwise.ukDrill these facts in the app

Traps examiners saw

Skipping the relay neurone entirely and saying the impulse goes straight from sensory to motor neurone
Saying the impulse 'passes to the next neurone' without naming the synapse and the chemical/neurotransmitter mechanism
Forgetting to name the effector (a muscle) and the specific response (contraction)

Full-mark self-check 0 of 4

Have I named the receptor and the specific stimulus it detects?Have I correctly sequenced sensory neurone, relay neurone and motor neurone in that order?Have I named the synapse and its chemical/neurotransmitter mechanism at each neurone junction?Have I named the effector as a muscle and described the resulting contraction?

The method for every 6-mark extended response — same every sittingMark bands, steps, timing

What this question type rewards

The topic changes by sitting — the mark scheme never does. Learn this once, then open your question above for that sitting’s sources and a full worked answer.

Naming the receptor and the specific stimulus it detects
Correctly sequencing sensory neurone, relay neurone (in the spinal cord or CNS) and motor neurone
Naming the synapse and the fact that a chemical (neurotransmitter) crosses the gap between neurones
Naming the effector (a muscle) and the resulting response (contraction)

Full marks (6 marks)Every stage of the pathway, receptor, sensory neurone, synapse, relay neurone, synapse, motor neurone, effector, is named in the correct order with the correct mechanism at synapses.

Partial marksMost stages present but with a step skipped, out of order, or the synapse mechanism (chemical/neurotransmitter crossing the gap) omitted.

The steps

Start with the receptor detecting the specific stimulus described in the question
Trace the impulse along the sensory neurone to the spinal cord
Name the synapse, where impulses pass from sensory to relay neurone via a neurotransmitter
Continue along the relay neurone, then across another synapse to the motor neurone
Finish with the effector (a muscle) contracting to produce the reflex response

6 marks, about 6 to 7 minutes. Write the pathway as a clear numbered or sequential list of stages

Try one now — from our question bank

Which word best describes a reflex action?

This question always wants the full pathway named in the correct order, receptor to sensory neurone to synapse to relay neurone to synapse to motor neurone to effector. Missing a stage loses marks even if the general idea is right.

Practise reflex arc questions

The paper is a template

“Describe how microorganisms in the layers of soil help to recycle chemicals in the dead plants, and how the chemicals are used again by living plants.”

What it’s really asking

What the sources actually showed — June 2021

The full worked answer — June 2021

What the sources actually showed — June 2023

The full worked answer — June 2023

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 4

What this question type rewards

The steps

“Explain what happened to the growth of the seedling on side Q compared with the growth on side P.”

What it’s really asking

What the sources actually showed — June 2020

The full worked answer — June 2020

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 3

“Describe the evidence from Figure 14 which supports the hypothesis that light causes auxin to move from the side of the shoot nearest the light to the side furthest from the light.”

What it’s really asking

What the sources actually showed — June 2022

The full worked answer — June 2022

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 3

What this question type rewards

The steps

“The results show that when the ice-cold water was drunk, the temperature near the brain decreased. Explain why the temperature near the brain decreased.”

What it’s really asking

What the sources actually showed — June 2021

The full worked answer — June 2021

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 2

“An echidna can dilate and constrict blood vessels in its skin. Explain how the dilation of blood vessels in the skin can help to decrease body temperature.”

What it’s really asking

What the sources actually showed — June 2022

The full worked answer — June 2022

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 3

What this question type rewards

The steps

“Explain the effect a high concentration of insulin has on blood glucose concentration.”

What it’s really asking

What the sources actually showed — June 2022

The full worked answer — June 2022

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 3

“Explain how the concentration of substance Q in the blood is controlled by negative feedback.”

What it’s really asking

What the sources actually showed — June 2023

The full worked answer — June 2023

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 3

What this question type rewards

The steps

“Person 7 and person 8 in Figure 6 are expecting a fourth child. What is the probability of the child having Dupuytren's?”

What it’s really asking

What the sources actually showed — June 2020

The full worked answer — June 2020

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 4

“Persons 8 and 9 in Figure 14 are expecting a second child. Determine the probability that the child will be a girl with sickle cell trait.”

What it’s really asking

What the sources actually showed — June 2021

The full worked answer — June 2021

What the mark scheme rewarded

Traps examiners saw

Full-mark self-check 0 of 4

“Persons 7 and 8 in Figure 4 are expecting a fourth child. Determine the probability that the child will have MSUD.”

What it’s really asking

What the sources actually showed — June 2022

The full worked answer — June 2022

What the mark scheme rewarded

Traps examiners saw