Explain why studying the structure and functions of the brain is extremely difficult. In your answer, refer to the challenges of obtaining consent, the number of neurones, and the limitations of non-invasive scanning methods.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Scientists use a range of methods to investigate the brain, including functional magnetic resonance imaging (fMRI) and electrical stimulation. Understanding which areas of the brain control which functions could help develop cures for diseases such as Alzheimer's and Parkinson's disease.
Model answer (5 marks)
The brain contains billions of neurones, making it extremely complex to study.
The brain must still be working/the patient must be alive in order to study the function of neurones.
Patients with brain damage may not be able to give informed consent, raising ethical issues.
Brain damage rarely causes a single problem, so it is difficult to match which problem is caused by which damaged neurones.
Non‑invasive scanning methods (e.g. fMRI) are expensive and/or have poor temporal or spatial resolution and/or may cause tissue damage.
The brain must still be working/the patient must be alive in order to study the function of neurones.
Patients with brain damage may not be able to give informed consent, raising ethical issues.
Brain damage rarely causes a single problem, so it is difficult to match which problem is caused by which damaged neurones.
Non‑invasive scanning methods (e.g. fMRI) are expensive and/or have poor temporal or spatial resolution and/or may cause tissue damage.
Examiner tips
- Use the exact wording from the mark scheme – e.g. ‘billions of neurones’ and ‘non‑invasive scanning methods’.
- Show each point as a separate sentence to match the 5‑mark structure.
- Mention both ethical and technical difficulties to cover all criteria.
Common mistakes
- Confusing ‘neurones’ with ‘neurons’ – use the UK spelling ‘neurones’.
- Omitting the point about patients not being able to give informed consent.
Mark scheme (5 marks)
- The brain contains billions of neurones, making it extremely complex to study
- The brain must still be working/the patient must be alive in order to study the function of neurones
- Patients with brain damage may not be able to give informed consent, raising ethical issues
- Brain damage rarely causes a single problem, so it is difficult to match which problem is caused by which damaged neurones
- Non-invasive scanning methods (e.g. fMRI) are expensive and/or have poor temporal or spatial resolution and/or may cause tissue damage
Key terms in this question
Related
- All Eduqas A-Level Biology revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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