Biology 9700 · AS & A Level · Antibiotics

Antibiotics — practice question

Tuberculosis (TB) is an infectious disease brought about by the bacterium Mycobacterium tuberculosis.
(a)[2]

Describe how TB is passed on.

(b)[4]

Streptomycin was the first antibiotic used to treat TB. In the first few years after streptomycin treatment was introduced, more and more $M.\ tuberculosis$ bacteria became resistant to streptomycin. Outline how this happened.

(c(i))[2]

Explain the meaning of transcription.

(c(ii))[1]

M. tuberculosis and humans both use RNA polymerase for transcription. Suggest why rifampicin has no effect on transcription in human cells.

(d)[3]

Other drugs such as isoniazid are also used in the treatment of TB. Some bacteria are now resistant to more than one of these drugs. These bacteria are called multi-drug resistant (MDR) bacteria. Outline the steps that can be taken to lessen the impact of drug resistance in bacteria.

(e)[2]

Explain why antibiotics can be used to treat bacterial infections but not viral infections.

Worked solution & mark scheme

This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: Transmission by airborne/aerosol/droplet infection

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