6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
When a person is infected by a pathogen for the first time, they may become ill, but if the same pathogen infects them again later they often do not become ill.
Explain how the body's immune system defends against a pathogen, and why the person is immune to that same pathogen in future. Refer to white blood cells, antibodies and memory cells in your answer. (6 marks)
A town has 2500 young children. In one year, 2000 of these children were vaccinated against measles.
(a) Calculate the percentage of the children who were vaccinated. Show your working. (2 marks)
(b) Explain how vaccinating a large percentage of the children helps to protect even the children who were not vaccinated. (2 marks)
Pathogens that cause communicable diseases include bacteria and viruses.
(a) State one way in which a communicable disease can be spread from person to person. (1 mark)
(b) Antibiotics can be used to treat some diseases. Explain why antibiotics are effective against bacterial infections but not against diseases caused by viruses. (2 marks)
Before a new medicine can be given to patients, it is tested in a series of stages.
Describe three things that are tested or checked when a new medicine is developed, before it is approved for use. (3 marks)
A person is described as being in good health.
(a) State what is meant by health. (1 mark)
(b) Give one example of a non-communicable disease and state why it is described as non-communicable. (1 mark)
Diseases are caused by different types of pathogen.
Name the type of pathogen that causes measles. (1 mark)