Blood samples were taken from two people. Person A does not have HIV. Person B has untreated HIV. Each sample was mixed with the same type of bacteria, starting with 100 bacterial cells per cm³, and kept under the same conditions for 6 hours.
| Person | White blood cells per mm³ | Bacterial cells per cm³ after 6 hours |
|---|---|---|
| A | 5000 | 120 |
| B | 1000 | 640 |
Explain how these results support the idea that untreated HIV increases a person's susceptibility to other infections.
112 exam-style questions on Edexcel GCSE Biology 5.1 Health and communicable disease, covering 5.1.1 Communicable and non-communicable diseases, 5.1.2 Disease susceptibility interactions, 5.1.3 Pathogens as disease-causing organisms, 5.1.4 Common infections, 5.1.5 Spread and prevention of pathogens, 5.1.6 Lifecycle of a virus, and 5.1.7 Spread and prevention of STIs. Each one has a worked solution and a mark scheme showing where the marks go.