Biology 9700 · AS & A Level · Antibodies and vaccination

Antibodies and vaccination — practice question

B-lymphocytes respond to the presence of a non-self antigen by dividing, as illustrated in Fig. 4.1.
(a(i))[2]

Explain what the term non-self antigen means.

(a(ii))[2]

Outline how B-lymphocytes identify non-self antigens.

(b(i))[4]

Outline how plasma cells make antibody molecules.

(b(ii))[2]

Describe how antibody molecules are secreted from the plasma cell.

(c)[3]

The cells labelled R on Fig. 4.1 divide to produce more cells that do not become plasma cells. These cells play an important part in the immune system. Explain the role of these cells.

(d)[2]

State what occurs at W and Z to alter the mass of DNA in each cell.

(e)[3]

Acute lymphoblastic leukaemia (ALL) is a cancer of B-lymphocytes. It is very uncommon in adults, but more common in children. A study in 2009 found that exposure to tobacco smoke in the home may put children at risk of developing ALL. Suggest how smoking by adults in the home may place their children at risk of cancers, such as ALL.

Worked solution & mark scheme

This 18-mark question has a full step-by-step worked solution and mark scheme. One marking point: Antigen recognised as non-self/foreign

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