Biology 0610 · IGCSE · Diseases and immunity

Diseases and immunity — practice question

Fig. 4.1 shows a virus diagram.
(a)[2]

Identify the parts of the virus labelled N and O.

(b(i))[3]

Use the information in Fig. 4.2 to calculate the percentage change in the number of lymphocytes from month 10 to month 60. Round your answer to two significant figures.

(b(ii))[2]

Describe the changes in the number of lymphocytes, over the 84 months following infection with HIV, shown in Fig. 4.2.

(b(iii))[4]

Outline the consequences of the changes in the number of lymphocytes for the health of the person infected with HIV.

(b(iv))[2]

Explain why antibiotics are not used to treat viral infections.

Worked solution & mark scheme

This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: N - protein coat

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