Plant defences and the human immune system

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Question 15

Table 1 shows the number of recorded pertussis (whooping cough) cases in a regional population between 1960 and 2000.

Table 1: Annual recorded pertussis cases

Year	Number of pertussis cases
1960	114 000
1970	28 500
1980	7 200
1990	1 150
2000	120

Explain one conclusion that can be made from these data about the change in the number of pertussis cases and suggest a biological explanation for it.

[2]

Plant defences and the human immune system

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Question 15

Table 1 shows the number of recorded pertussis (whooping cough) cases in a regional population between 1960 and 2000.

Table 1: Annual recorded pertussis cases

Year	Number of pertussis cases
1960	114 000
1970	28 500
1980	7 200
1990	1 150
2000	120

Explain one conclusion that can be made from these data about the change in the number of pertussis cases and suggest a biological explanation for it.

[2]

Plant defences and the human immune system

Question 15

Table 1: Annual recorded pertussis cases

Plant defences and the human immune system Questions

Plant defences and the human immune system

Question 15

Table 1: Annual recorded pertussis cases

Plant defences and the human immune system Questions