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Measles is a serious disease - AQA - GCSE Biology Combined Science - Question 5 - 2018 - Paper 1
Question 5
Measles is a serious disease. A person can die from measles. Table 3 shows the number of medically confirmed cases of measles in England and Wales between 2012 and ... show full transcript
Worked Solution & Example Answer:Measles is a serious disease - AQA - GCSE Biology Combined Science - Question 5 - 2018 - Paper 1
Step 1
Step 2
Calculate the percentage decrease in the number of medically confirmed cases of measles between 2012 and 2015.
Answer
To calculate the percentage decrease:
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Find the difference in cases: 2030 - 91 = 1939.
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Divide by the original amount:
\frac{1939}{2030} \times 100 \approx 95.5%.
Therefore, the percentage decrease is approximately 95.5%.
Step 3
One reason for the decrease in the number of cases of measles is that more children were vaccinated against the disease. Explain why.
Answer
Vaccinating a large proportion of the population leads to herd immunity. This means that most people are immune, reducing the chances of the virus spreading. Consequently, fewer individuals can catch and transmit the disease, protecting even those who are unvaccinated.
Step 4
Explain the differences between antibody production after the vaccine injection and after exposure to the measles virus.
Answer
After vaccination, antibody production is typically quicker and results in higher concentrations of antibodies as seen in Figure 8, where a peak occurs shortly after vaccination. However, after exposure to the measles virus, the antibody response is usually slower and may not reach the same concentration levels. The figure shows a gradual increase after exposure, indicating that the immune response to the virus is not as immediate as with vaccination.