CAIE A Level Biology 9700 · Infectious diseases
In a rural area, an outbreak of cholera occurred after heavy rainfall caused a river to overflow, contaminating the main drinking water well. Many people became ill with severe diarrhoea. Outline how cholera is transmitted and explain why providing a clean water supply is an important factor in controlling the spread of the disease.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Outline means: Give the main points briefly. Less detail than describe, but every key step has to be there. One short line per step, in order. The marks are for coverage, not depth.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.