Biology 9700 · AS & A Level · The immune system

The immune system — practice question

Alveolar macrophages are immune system cells that stay within the alveolar part of the gas exchange system. They help to prevent infection by pathogens that have been inhaled.
(a(i))[3]

Complete Table 2.1 by naming the cell structures that correspond to the stated functions. Do not use abbreviations.

(a(ii))[2]

Fig. 2.1 shows an alveolar macrophage together with some of the cell structures that would be visible with an electron microscope, plus a newly formed phagocytic vacuole (phagosome) containing two cells of Mycobacterium tuberculosis. The cell structures with the functions described in Table 2.1 are not shown in Fig. 2.1. Complete Fig. 2.1 by drawing and labelling the cell structures described in Table 2.1.

(b(i))[2]

Outline the sequence of events that results in formation of a phagocytic vacuole after the bacterial cells are detected by an alveolar macrophage.

(b(ii))[1]

Name the cell structures that merge with the phagocytic vacuole and release hydrolytic enzymes to destroy the bacterial cells.

(c)[4]

Apart from being cost effective, suggest and explain the advantages of using the Bacillus Calmette-Guérin (BCG) vaccine for the prevention and control of tuberculosis (TB).

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