The brain (biology only) — AQA GCSE Biology

SPEC 4.5.2.2 • PAPER 2 • BOTH TIERS

BIOLOGY ONLY — NOT ON COMBINED SCIENCE

The Brain

Three named regions to identify on a diagram, their functions, and (HT-flagged) why investigating the brain is so difficult.

Why This Lesson Wins Marks

AQA Paper 2 brain questions follow a tight pattern: identify a region on a labelled diagram (1 mark each) and match it to its function (1 mark each). For Higher Tier students, you also need to know how neuroscientists investigate the brain and why it's so hard. Easy marks — if you've nailed the three named regions.

3

Named Regions To Know

3

Investigation Methods (HT)

P2

Paper 2 Only

Biology Only — Important

This entire lesson is on the AQA GCSE Biology 8461 specification only. Combined Science students do not need this content. If you're sitting Combined Science, skip to Lesson 5.05.

By The End You'll Be Able To…

1. Identify

Identify the cerebral cortex, cerebellum, and medulla on a labelled diagram of the brain.

2. Describe

Describe the function of each of the three named regions.

3. Explain HT

Explain how neuroscientists map brain function using brain-damage studies, electrical stimulation, and MRI scanning.

4. Evaluate HT

Explain why investigating brain function and treating brain disorders is so difficult, and weigh up the benefits and risks of brain procedures.

The Brain — The Headlines

Spec Definition

The brain controls complex behaviour. It is made of billions of interconnected neurones and has different regions that carry out different functions.

Function

The brain coordinates complex behaviour — thinking, memory, voluntary movement, and many automatic processes you don't think about (breathing, heart rate).

Structure

Built from billions of interconnected neurones. The brain isn't one uniform organ — it has different regions doing different jobs.

Link To 5.02

The brain + spinal cord form the CNS you met in Lesson 5.02. The brain handles the complex jobs — conscious thought, learned behaviour. The spinal cord handles reflexes (without involving the conscious brain).

The Three Named Regions

The spec asks you to identify these three regions on a diagram. AQA exam questions show a labelled brain diagram and ask you to name the parts. Memorise the locations.

Quick Locator

Cerebral cortex = the big wrinkly top · cerebellum = the small back-bottom region · medulla = the brain stem leading down to the spinal cord.

Exam Diagrams Vary

AQA exam diagrams of the brain can be drawn in different views — usually a sagittal (cross-section) view rather than the simplified side view shown above. Don't memorise the exact shape — memorise the positions: cerebral cortex on top/outer, cerebellum at the lower back, medulla as the brain stem.

What Each Region Does

The spec wants you to "describe their functions". Mark schemes credit specific function words — memorise them.

Cerebral Cortex

Outer / top — largest region

Consciousness, intelligence, memory, language, decision-making. Anything you "think about" happens here.

Cerebellum

Lower back of brain

Balance and coordination of movement. Damage causes clumsiness, not unconsciousness.

Medulla

Brain stem (connects to spinal cord)

Unconscious activities — controlling heart rate and breathing rate.

Accepted Alternative Names

AQA mark schemes allow "cerebrum" or "cerebral hemisphere(s)" as alternatives for cerebral cortex. They do not accept generic terms like "brain matter" or "front part of brain".

Memory Hook

Cortex = Cleverness (consciousness, thinking, decisions) · Cerebellum = Coordination (balance, movement) · Medulla = Maintenance (heart, breathing — the auto-pilot).

Mapping The Brain HT Only

How do neuroscientists work out which region does what? The spec names three methods. Memorise these — they're the answer to "how have we identified what different regions do" questions.

1 Studying patients with brain damage

If damage to a specific region causes loss of a specific function, that region must be responsible for that function. Example: damage to the cerebellum → loss of balance.

2 Electrically stimulating different parts of the brain

During brain surgery, scientists can apply small electrical currents to specific regions and observe the response (e.g. a muscle twitches). This shows what function that region controls.

3 MRI scanning

MRI scanners show which regions are active while a person does a particular task (thinking, reading, moving). Comparing scans of healthy people to those with brain damage reveals which regions are linked to which function.

Why MRI Is Powerful

You can ask people to do specific tasks (e.g. read a word, recall a memory, move a hand) while being scanned, and see which part of the brain lights up. Non-invasive — no surgery needed. This is what the Specimen P2 mark scheme credits for MRI benefits.

Why The Brain Is Hard To Investigate HT Only

Spec Wording

The complexity and delicacy of the brain makes investigating and treating brain disorders very difficult.

Complexity

Billions of neurones with trillions of connections

Multiple regions interact for most functions — hard to isolate one region

No two brains are identical

Delicacy

Brain tissue is easily damaged — surgery is high-risk

Enclosed in the skull, hard to access directly

Damaged neurones generally do not regrow

Treating Brain Disorders Is Also Difficult

The same complexity and delicacy makes treatment hard: surgery risks damaging nearby healthy tissue, and the brain doesn't heal as well as other tissues because damaged neurones generally don't regrow. AQA frequently asks about both investigation and treatment difficulties.

Risks vs Benefits of Brain Procedures HT Only

The spec's WS 1.5 skill asks you to evaluate the benefits and risks of procedures carried out on the brain and nervous system. This is a typical 4–6 mark "evaluate" question.

Potential Benefits

Remove or shrink tumours

Treat severe epilepsy by removing problem tissue

Restore or improve a lost function

Identify exactly where damage / disease is located (for diagnosis)

Potential Risks

Damage to healthy tissue near the target area

Permanent loss of function (memory, language, movement)

Risks of anaesthesia / surgical complications

Outcomes hard to predict due to brain complexity

Exam Approach

For "evaluate" questions, give at least one benefit and one risk, then write a brief judgement — e.g. "the procedure may be worthwhile if the condition is life-threatening and untreatable otherwise, but the risk of permanent loss means it's a last resort." That judgement is often where the final mark sits.

Worked Example — PEE

Original 3-mark question in AQA's style. Uses the PEE framework to build a structured answer.

"A patient suffers brain damage after a stroke and can no longer maintain balance when walking. Suggest which region of the brain is most likely to have been damaged and explain how scientists could confirm this." — Practice question · 3 marks · AO2 · Spec 4.5.2.2 · biology only

P

Point: The damaged region is most likely the cerebellum(1 mark).

E

Evidence: The cerebellum controls balance and coordination of movement, and balance has been lost (1 mark).

E

Explain: Scientists could confirm this by using an MRI scan to identify the damaged region, or by comparing the patient with people who have damage to other regions to see which region's damage matches this loss of balance (1 mark).

Mark Scheme Match

✓ Cerebellum named · ✓ Function (balance/coordination) matched to lost ability · ✓ MRI or brain-damage study used to confirm. 3/3.

Practice Question

(a) Name the region of the brain that controls heart rate and breathing rate.1 MARK

(b) Name the region of the brain responsible for memory, language and intelligence.1 MARK

(c) HT Explain two reasons why investigating brain function is difficult.2 MARKS

(d) HT Describe one method scientists use to map regions of the brain to particular functions.2 MARKS

(a)

Medulla. (1 mark — must be the exact named region.)

(b)

Cerebral cortex (or cerebrum / cerebral hemisphere). (1 mark)

(c)

Any two from: the brain is extremely complex, containing billions of interconnected neurones (1 mark); functions often involve multiple regions interacting, so isolating a single region is hard (1 mark); the brain is delicate / easily damaged, so investigation by surgery carries risks (1 mark); the brain is enclosed in the skull, making direct access difficult (1 mark).

(d)

One of: (i) Studying patients with brain damage — link the lost function to the damaged region (2 marks); OR (ii) Electrically stimulating different parts of the brain and observing the response (2 marks); OR (iii) MRI scanning — ask the patient to do a task while being scanned to see which region is active (2 marks).

⚠️

Mark-loss check: For (a) and (b) the named region is essential — generic answers like "brain stem" or "front of brain" don't score. For (c) "the brain is hard" is too vague — you need a specific reason (complexity OR delicacy + a consequence). For (d) just naming a method (e.g. "MRI") is 1 mark — describing how it identifies function gets the second mark.

Two Examiner Alerts

Patterns from AQA mark schemes and examiner reports specifically for brain questions.

Alert 1 — Exact Region Names

For "name this region" questions, AQA wants the specific name. "Brain stem" doesn't score for medulla. "Top of brain" doesn't score for cerebral cortex. Accepted alternatives for cerebral cortex: "cerebrum" or "cerebral hemisphere(s)" — but nothing more generic.

Alert 2 — Region Confusion

The two most-confused regions are cerebellum (balance/movement) and medulla (heart rate/breathing). They're both at the lower back of the brain — students often mix them up. Memorise: CerebellUM = movement (limbs); MeDULLA = automatic life support (heart, lungs).

Alert 3 — "Hard To Investigate" Needs Reasons

For HT questions asking why the brain is hard to investigate, vague answers like "it's complicated" don't score. AQA wants specific reasons: complexity (billions of neurones, regions interacting), delicacy (easily damaged, surgery is risky), or location (enclosed in skull). Each reason = a mark.

Common Errors

Phrasings that lose marks vs phrasings that win them. The right column is what mark schemes credit.

✗ Wrong

"The cerebellum controls thinking and memory."

Wrong region — cerebellum is balance/coordination.

✓ Correct

"The cerebral cortex controls consciousness, intelligence, memory, language and decision-making."

Spec wording, correct region.

✗ Wrong

"The medulla controls movement and balance."

Confused with cerebellum.

✓ Correct

"The medulla controls unconscious activities — heart rate and breathing rate."

Right region matched to right function.

✗ Wrong

"MRI shows blood flow."

Too narrow — doesn't explain how it maps function.

✓ Correct

"MRI shows which regions are active when a person does a specific task — building a map of which region controls which function."

Connects technique to spec's "map regions to functions".

✗ Wrong

"The brain is hard to operate on because it's important."

Circular — doesn't give a specific reason.

✓ Correct

"Brain tissue is delicate and easily damaged, so surgery risks causing permanent loss of function in nearby healthy regions."

Names the property (delicacy) + the consequence.

Summary

The Brain (Spec 4.5.2.2 · Biology Only · Paper 2)

The brain controls complex behaviour

Made of billions of interconnected neurones

Different regions carry out different functions

Three Named Regions To Identify On A Diagram

Cerebral cortex (outer / top) — consciousness, intelligence, memory, language, decision-making

Cerebellum (lower back) — balance, coordination of movement

Medulla (brain stem) — unconscious activities: heart rate, breathing rate

Mapping Brain Function HT

Studying patients with brain damage — link lost function to damaged region

Electrically stimulating different parts of the brain — observe the response

MRI scanning — see which regions are active during specific tasks

Why Investigation & Treatment Are Difficult HT

Complexity — billions of neurones, regions interact, no two brains identical

Delicacy — easily damaged, surgery is high-risk, neurones don't regrow

Location — enclosed in the skull, hard to access directly

Exam Tip

Brain questions are typically short and specific — 1 mark for naming a region, 1 mark for matching it to a function. Don't waste time over-writing. For HT "explain why" questions, give a named reason + a consequence per mark.