Explain why studying the brain to understand diseases such as Alzheimer's is difficult.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Scientists use techniques such as functional magnetic resonance imaging (fMRI) to investigate the brain. However, there are many challenges involved in researching the brain and finding cures for brain diseases.
Model answer (5 marks)
The brain contains billions of neurons, making it extremely complex to study.
The brain must still be functioning, so the patient must be alive to investigate many brain functions.
Ethical issues arise because patients with brain damage may be unable to give informed consent.
Studies are usually carried out only after damage has occurred, so the brain cannot be compared to the patient’s healthy brain.
Brain damage rarely causes a single problem, making it difficult to link a specific deficit to a particular damaged neuron or area.
The brain must still be functioning, so the patient must be alive to investigate many brain functions.
Ethical issues arise because patients with brain damage may be unable to give informed consent.
Studies are usually carried out only after damage has occurred, so the brain cannot be compared to the patient’s healthy brain.
Brain damage rarely causes a single problem, making it difficult to link a specific deficit to a particular damaged neuron or area.
Examiner tips
- Use the exact points from the mark scheme in order; each point is worth one mark.
- Show understanding of why each point makes research difficult.
- Keep sentences short and to the point.
Common mistakes
- Mixing up the order of the points, losing a mark for a misplaced point.
- Adding unnecessary details such as specific imaging techniques that are not asked for.
Mark scheme (5 marks)
- There are billions of neurones in the brain, making it complex to study
- The brain must still be working / the patient must be alive to study many brain functions
- There are ethical issues — patients with brain damage may not be able to give informed consent
- Studies are only carried out after damage has occurred, so the brain cannot be compared to the patient's healthy brain
- Brain damage rarely causes a single problem, so it is difficult to match a specific problem to specific damaged neurones / area
Related
- All Eduqas A-Level Biology revision notes →
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- Decode the mark scheme abbreviations →
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