Biology (4-period option) / Science, Technology and Society (STS)
What the Biology option tests
The 4-period Biology option examines mechanisms, terminology and data interpretation across cell biology, genetics, evolution, ecology and physiology. You must explain processes causally, interpret experiments and use genetic ratios or probabilities accurately. Descriptions that name a structure without explaining its function rarely reach the top band.
What STS tests
Science, Technology and Society examines how scientific evidence interacts with technology, policy, ethics and stakeholders. You should distinguish evidence from opinion, identify uncertainty and risk, compare costs and benefits, and recognise that ethical disagreement is not settled by data alone.
Core rules
- Biology: use precise terms such as allele, genotype, phenotype, penetrance and control.
- Genetics: separate the probability of inheriting a variant from the probability of developing a condition.
- STS: identify the claim, the evidence, the stakeholder and the value judgement.
- Evaluate risk communication: absolute versus relative risk, false reassurance and false alarm.
- Link regulation and consent to scientific uncertainty rather than treating them as afterthoughts.
Worked example
A private clinic advertises: “Know your future: the BRCA1 test tells you whether you will get breast cancer.” Biologically, pathogenic BRCA1 variants increase lifetime risk substantially but do not determine outcome; penetrance is incomplete and other genes, hormones, lifestyle and chance matter. The test detects a variant, not a certainty. In STS terms, the advertisement converts a risk estimate into a promise, ignores genetic counselling and informed consent, and raises privacy and insurance questions. A strong answer concludes that the test can inform risk management but cannot tell an individual “whether” they will develop cancer; regulation of direct-to-consumer advertising is therefore a legitimate policy issue.
Traps that cost marks
Genetic determinism; confusing correlation with causation; ignoring sample size or missing controls; treating a risk factor as a diagnosis; and presenting an ethical preference as a scientific fact. In STS answers, unsupported claims about “society” or “progress” without a named stakeholder or trade-off lose credit.