Biology 9700 · AS & A Level · Infectious diseases

Infectious diseases — practice question

Plasmodium falciparum is one Plasmodium species that causes the potentially fatal disease malaria. If diagnosis is made early and the correct drug treatment is given, the pathogen can be removed from the body, especially when the illness is not severe.
(a)[1]

Name the pathogen type responsible for malaria.

(b)

To help stop drug resistance in Plasmodium from developing and spreading, the World Health Organization (WHO) advises using artemisinin-based combination therapy (ACT). ACT uses two different drugs: a fast-acting drug derived from a compound called artemisinin, which causes a rapid fall in the number of P. falciparum; and one or more longer-acting, non-artemisinin, drugs that remove any pathogens left behind.

(b(i))[2]

Suggest why using ACT with two different types of drug is more effective at preventing the development of drug resistance in Plasmodium than treatment with only one type of drug.

(b(ii))[2]

In some areas, partial artemisinin resistance has developed. This means ACT takes longer to eliminate the pathogen from the body. Explain why the risk of the pathogen being passed to other people is increased if a person is being treated with ACT and the pathogen has partial artemisinin resistance.

(c(i))[3]

Using gene kelch13 and mutation F446I as examples, explain how a gene differs from a gene mutation.

(c(ii))[3]

State the main conclusions that can be drawn from the results shown in Table 3.2.

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