A person with AIDS dies after a bad bout of pneumonia, an illness that a healthy body usually…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A person with AIDS dies after a bad bout of pneumonia, an illness that a healthy body usually fights off. Explain why this happens. Then name two things that do not spread HIV, and one way to prevent it.
Need a reminder? The key ideaShow
The immune system, led by white blood cells, kills microbes and remembers them. A vaccine is a harmless form of a microbe that trains it. Edward Jenner used cowpox against smallpox. Vaccinating most of a community protects those who are not vaccinated. HIV attacks the white blood cells themselves.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The weak defence. HIV attacks the white blood cells, which are the defenders of the body. When too many are destroyed, the immune system cannot fight even common infections.
Step 2. The death. The person dies of pneumonia, a common infection, and not of the virus directly.
Step 3. What does not spread HIV. A hug, a handshake, shared food or a mosquito bite.
Step 4. Prevention. Use a new, sterile needle for every injection, and use only tested blood.
Answer: HIV destroys the defenders, so ordinary infections become deadly. It is prevented by safe needles and tested blood.
Discussion (0)
Log in to join the discussion.
Loading…