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Which test strip shows a negative test result? Tick one box - AQA - GCSE Biology - Question 11 - 2018 - Paper 1
Question 11
Which test strip shows a negative test result? Tick one box. A B C D Monoclonal antibodies are used for pregnancy testing. Give one other use of monoclonal antib... show full transcript
Worked Solution & Example Answer:Which test strip shows a negative test result? Tick one box - AQA - GCSE Biology - Question 11 - 2018 - Paper 1
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Explain how the pregnancy test strip works to show a positive result.
Answer
The pregnancy test strip functions through a series of interactions involving monoclonal antibodies and the hormone HCG.
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Reaction Zone: When urine is applied, any HCG present will bind to the mobile antibodies specific to HCG which are attached to a blue dye.
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Movement: This complex then moves along the strip towards a region called the control window.
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Result Window: In the result window, there are immobilized antibodies specific to HCG. If HCG is present, it will form a visible line showing the positive test result.
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Control Window: The control window always displays a line if the test is working properly, confirming the test's validity regardless of the test result for HCG.