Edexcel GCSE Combined Science: Biology: Health, Disease and the Immune System
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.
A person is infected by a pathogen for the first time. They feel ill for about a week, then recover. If they later meet the same pathogen, they usually do not become ill.
Explain how the body's immune system responds to the pathogen on the first infection, and why the person is protected against that pathogen in the future. In your answer you should refer to white blood cells, antibodies and memory cells. (6 marks)
Pathogens are micro-organisms that cause communicable (infectious) diseases. The table below gives information about four diseases caused by different types of pathogen.
| Disease | Type of pathogen | Organism affected |
|---|---|---|
| Cholera | Bacterium | Humans |
| Influenza (flu) | Virus | Humans |
| Athlete's foot | Fungus | Humans |
| Malaria | Protist | Humans |
(a) Using the table, name a disease caused by a virus and a disease caused by a protist. (2 marks)
(b) Some plant diseases are also caused by pathogens. Name one named example of a plant disease and state the type of pathogen that causes it. (2 marks)
The body has defences that stop pathogens entering and reduce infection.
(a) The skin is described as a physical barrier. Explain how the skin helps to defend the body against pathogens. (1 mark)
(b) The stomach produces hydrochloric acid. Explain how this helps to protect the body from pathogens in food. (2 marks)
Immunisation (vaccination) protects people against communicable diseases.
(a) A vaccine contains a small amount of a dead or inactivated pathogen. Explain how being given this vaccine makes a person immune to the disease. (2 marks)
(b) Explain why a person who has been vaccinated against a disease does not become ill if they later meet the live pathogen. (1 mark)
Heart disease is a non-communicable disease. Smoking and a poor diet are risk factors for it.
Explain what is meant by a risk factor for a non-communicable disease, using smoking as an example. (2 marks)
Antibiotics are medicines used to treat some infections.
State which type of pathogen antibiotics are effective against. (1 mark)