Biology 9700 · AS & A Level · Infectious diseases

Infectious diseases — practice question

Fig. 4.1 illustrates the two base pairs in a DNA molecule.
(a)[3]

Name the bases indicated by J and K, and state the bond labelled L.

(b)[4]

Explain how the mode of action of zidovudine differs from that of efavirenz.

(c)[2]

People receiving drug treatment for HIV take a mixture of drugs that work in different ways. Suggest the advantage of taking a mixture of the drugs shown in Table 4.1.

(d)[2]

Antibiotics are given to people with HIV/AIDS to treat secondary infections, but they are not used to treat the HIV infection itself. Explain why this is so.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: The base J is thymine.

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