The graph below shows the antibody levels in the blood after a person has been exposed twice to the same pathogen - VCE - SSCE Biology - Question 21 - 2008 - Paper 1
Question 21
The graph below shows the antibody levels in the blood after a person has been exposed twice to the same pathogen.
With regard to this pathogen, we can conclude tha... show full transcript
Worked Solution & Example Answer:The graph below shows the antibody levels in the blood after a person has been exposed twice to the same pathogen - VCE - SSCE Biology - Question 21 - 2008 - Paper 1
Step 1
A. the person has a deficient immune response.
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Answer
This statement is not supported by the graph. The response shows a significant increase in antibody levels after the second exposure, indicating a functioning immune response.
Step 2
B. the virulence of the pathogen increased between the 1st and 2nd exposures.
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Answer
The graph does not provide evidence of a change in the virulence of the pathogen. The antibody response is typical of the immune system's memory and not necessarily indicating an increase in virulence.
Step 3
C. antibodies are only produced after a second exposure to the pathogen.
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Answer
This statement is incorrect. Antibodies are produced after the first exposure, but the levels are higher after a second exposure due to the immune memory.
Step 4
D. memory cells for antibodies against the pathogen exist at the time of the second exposure.
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Answer
This statement is correct. The graph indicates that memory cells were activated during the second exposure, leading to a rapid and high production of antibodies.
