Biology 9700 · AS & A Level · Infectious diseases

Infectious diseases — practice question

Tuberculosis (TB) is an infectious disease responsible for about three million deaths worldwide each year.
(a)[1]

Name the pathogenic organism responsible for tuberculosis.

(b(i))[2]

The real length of the cell between X and Y in Fig. 3.1 is $2\,\mu\text{m}$. Calculate the magnification of the electron micrograph. Show your working and give the answer to the nearest whole number.

(b(ii))[3]

The organism that causes tuberculosis is a prokaryote. State three characteristics of prokaryotes.

(c(i))[1]

State one factor, other than drug therapy, that helped bring about the steady decline in the number of new cases of tuberculosis.

(c(ii))[3]

Outline three reasons why, in many developed countries, the number of new cases of tuberculosis is now rising.

(d(i))[2]

Suggest two ways in which streptomycin acts at ribosomes to inhibit protein synthesis.

(d(ii))[1]

Streptomycin does not harm mammalian cells. Suggest an explanation for this.

Worked solution & mark scheme

This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: Mycobacterium bovis or Mycobacterium tuberculosis

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI