Practise 38 exam-style questions on Producing monoclonal antibodies (biology only) for AQA GCSE Biology. Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
38 questions
2–6 marks each
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20 questions, marked as you go
Sample questions with model answers
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Question 1
3 marks
What property of hybridoma cells makes them useful for producing large amounts of antibody?
Model answer
Hybridoma cells can both divide (are immortal/continue to grow in culture) and produce the specific antibody from the lymphocyte parent.
Explanation
Hybridomas combine the dividing ability of tumour cells with the antibody-producing function of lymphocytes, so they can be cultured to produce large quantities of one specific antibody.
Mark scheme
1 mark
they divide / are immortal / can be grown indefinitely
1 mark
they make the specific antibody (from the lymphocyte)
1 mark
therefore they produce large amounts of identical antibody
Question 2
3 marks
Why is it important to store monoclonal antibody stocks at recommended temperatures and what problems can occur if they are freeze–thawed repeatedly?
Model answer
Correct storage preserves stability, prevents denaturation and aggregation. Repeated freeze–thaw cycles promote aggregation, loss of activity (reduced binding), and increased immunogenicity.
Explanation
Temperature control prevents structural changes; aggregation from freeze–thaw degrades the product and can produce harmful immune responses.
Mark scheme
1 mark
storage at recommended temperatures preserves stability and activity
1 mark
freeze–thaw causes aggregation
1 mark
aggregation leads to reduced binding/activity and increased immunogenicity / safety issues
Question 3
4 marks
Explain why monoclonal antibodies used in diagnostics need to be validated for cross-reactivity against related human proteins and common environmental proteins.
Model answer
Cross-reactivity could give false positive results if the antibody binds related human proteins or contaminants; this reduces test specificity and clinical usefulness. Validation ensures accurate interpretation and avoids misdiagnosis or unnecessary treatment.
Explanation
Testing against potential cross-reactants demonstrates that the diagnostic antibody will selectively detect the intended target in patient samples.
Mark scheme
1 mark
cross-reactivity leads to false positives (antibody binds non-target proteins)
1 mark
false positives reduce specificity and clinical reliability of diagnostic tests
1 mark
related human proteins or environmental proteins may be present in samples
1 mark
validation prevents misdiagnosis and ensures test accuracy
Question 4
5 marks
Explain the difference between polyclonal and monoclonal antibodies, including how each is produced and one advantage of each.
Model answer
Polyclonal antibodies are a mixture produced by different B cell clones in an immunised animal; serum is collected and contains antibodies against multiple epitopes — advantage: robust detection (bind multiple epitopes) and easier/cheaper to produce. Monoclonal antibodies are from a single clone (hybridoma) and bind one epitope — advantage: high specificity and reproducibility.
Explanation
Polyclonals recognise multiple sites on an antigen, useful for detecting denatured or varied targets; monoclonals are uniform and highly specific, ideal when reproducibility and single-epitope targeting are required.
Mark scheme
1 mark
polyclonal: mixture of antibodies from different B cell clones (in serum)
1 mark
monoclonal: identical antibodies from a single clone (hybridoma)
1 mark
production: polyclonal from immunised animal serum
1 mark
production: monoclonal from cloned hybridoma cells
