AQA EXAM PAST PAPER QUESTIONS A LEVEL BIOLOGY - CELL RECOGNITION AND IMMUNE SYSTEMS

AQA
A-Level
BIOLOGY
3.2 | b Immunity
Cell Recognition and Immune system

Time allowed
50 minutes

QUESTION PAPER




Score Percentage

/40 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1

, Malaria is a disease caused by parasites belonging to the genus Plasmodium. Two species
that cause malaria are Plasmodium falciparum and Plasmodium vivax.

A test strip that uses monoclonal antibodies can be used to determine whether a person is
infected by Plasmodium. It can also be used to find which species of Plasmodium they are
infected by.

• A sample of a person’s blood is mixed with a solution containing an antibody, A, that
binds to a protein found in both species of Plasmodium. This antibody has a
coloured dye attached.
• A test strip is then put into the mixture. The mixture moves up the test strip by
capillary action to an absorbent pad.
• Three other antibodies, B, C and D are attached to the test strip. The position of
these antibodies and what they bind to is shown in Figure 1.

Figure 1




(a) Explain why antibody A attaches only to the protein found in species of
Plasmodium.


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(2)