Biology 9700 · AS & A Level · Antibodies and vaccination

Antibodies and vaccination — practice question

The diseases myasthenia gravis (MG) and HIV/AIDS are both disorders of the immune system.
(a)[2]

The cause of MG includes a response involving B-lymphocytes. Explain why MG is described as a disorder of the immune system.

(b)[3]

Studies have shown that T-lymphocytes are involved in stimulating the B-lymphocyte response that leads to MG. Research has been done on a vaccine that will give a person active immunity against these T-lymphocytes and B-lymphocytes. Suggest and explain how this vaccine will provide a person with active immunity against the T-lymphocytes and B-lymphocytes responsible for causing MG.

(c)[1]

Many people living with HIV (infected with HIV) develop tuberculosis (TB). If a person has no symptoms of TB, one preventive measure is to prescribe antibiotics. This lowers the total number of TB cases and TB deaths. State the disadvantage of prescribing antibiotics as a preventive measure against TB.

(d)[3]

Fig. 6.1 summarises some of the statistics published by UNAIDS (Joint United Nations Programme on HIV and AIDS) about HIV and HIV/AIDS for the year 2017. The values shown in Fig. 6.1 for 2017 are estimates.\n\nAnother statistic published by UNAIDS showed that, in 2017, only $75\%$ of the estimated $36.9$ million people living with HIV knew that they had been infected with the virus. With reference to the information in Fig. 6.1, discuss why this statistic is important.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Myasthenia gravis is an autoimmune disorder

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