AQA GCSE Biology Biology Paper 1 (Foundation), June 2022: Question 1

✅ Correct Answer

[✓] Sexual intercourse

💡 Key Knowledge

HIV (Human Immunodeficiency Virus) is spread via the exchange of bodily fluids, primarily through:

• Unprotected sexual intercourse
• Sharing needles contaminated with infected blood

❌ Common Errors

Confusing HIV transmission with droplet infections (coughing/sneezing like flu or measles) or contact transmission via door handles (like norovirus).

✅ Correct Answer

Must identify both stages of the trend:

1. Number of cases increased (from 2010 to 2014) [1 mark]
2. Then decreased (from 2014 to 2018) [1 mark]

🧠 Exam Technique: "Describe what happened"

• Look at all data points in the table, not just the start and end!
• 2010: 2642 → 2014: 2767 (rise) → 2018: 1530 (fall).
• A 2-mark trend question almost always contains a change in direction (up then down, or slow then fast).

❌ Common Errors

Examiners will ignore numbers quoted without explanation. Writing "In 2010 it was 2642 and in 2018 it was 1530" does not describe what happened. Do not state there was an "overall increase".

✅ Correct Answer

[✓] Better education on how to prevent the spread of HIV

💡 Key Knowledge

Public health campaigns educating people about using barrier contraception (condoms) and avoiding needle-sharing directly decrease pathogen transmission rates.

• 1 mark for link E → A
• 1 mark for link A → B
• 1 mark for link B → D
• Special allowance: If no other mark is awarded, allow 1 mark for (C) → E → B → A → D.

💡 Step-by-Step Logic

1. C: Inactive virus injected into the body.
2. E: White blood cells detect antigens and produce specific antibodies.
3. A: Antibodies attach to antigens on the inactive virus.
4. B: Antibodies destroy the inactive virus.
5. D: Memory cells remain, so if the active virus enters later, antibodies are produced quickly.

🧠 Exam Technique: Chain Marks

Even if you make a mistake with one letter, keep the remaining sequence logical! Examiners mark sequential pairs (e.g., E before A, A before B, B before D), meaning one error does not necessarily lose all 3 marks.

✅ Correct Answer

[✓] Testing on healthy volunteers

💡 Stages of Drug Development

1. Preclinical: Tested on isolated human cells & tissues.
2. Preclinical: Tested on live laboratory animals (for toxicity & efficacy).
3. Clinical Phase 1: Tested on healthy human volunteers at very low doses to check for safety and side effects.
4. Clinical Phase 2 & 3: Tested on patients with the disease to find optimum dose and check efficacy.

❌ Common Errors

Selecting "Testing on cells in a laboratory" shows confusion about the order: cell testing happens before animal testing, not after.

✅ Correct Answer

[✓] Drugs that destroy viruses also damage body tissues.

💡 Why Viruses are Hard to Kill

Viruses are intracellular pathogens—they reproduce inside host cells using the cell's own machinery. Therefore, it is very difficult to design drugs that destroy the virus without also damaging host cells and body tissues.

❌ Common Errors

Thinking viruses can be killed by antibiotics. Antibiotics kill bacteria only; they have no effect on viruses.

✅ Correct Matches

💡 Traditional Plant Medicines to Memorise

• Aspirin (painkiller) originates from the bark of willow trees.
• Digitalis (heart drug) originates from foxgloves.
• Bonus recall: Penicillin was discovered by Alexander Fleming from Penicillium mould (a fungus).