Interpret herd immunity threshold
A model in a advanced investigation workshop shows disease spread slowing as the immune proportion of the population increases. Explain the population-level effect. Use the labelled diagram, data, or experimental evidence before writing the answer. Enter the answer and choose the interpretation that best matches the HL Biology evidence.
Worked practice: biological evidence and answer
Use the labelled biological evidence first, then connect it to the final answer.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.