CAIE A Level Biology 9700 · Infectious diseases
In 2021, a cholera outbreak in a coastal town was traced to a municipal water supply contaminated after flooding. Explain how the bacterium Vibrio cholerae is transmitted, and why providing clean water is considered essential for the control of cholera outbreaks.
6 marks, so the mark scheme is looking for about 6 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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