Question 1
What is a pathogen?
- A disease-causing organism
- A protein that fights disease
- A cell that engulfs bacteria
- A chemical that kills bacteria
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Answer: A (1)
Question 2
Define the term transmissible disease and give two ways in which a pathogen can be transmitted indirectly.
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- a disease in which the pathogen can be passed from one host to another (1)
- contaminated surfaces / food / animals / air (1)
- any second different indirect route, e.g. contaminated food (1)
- allow water for food; ignore touching without reference to a surface
- Max 3
Question 3
Which is an example of transmission by direct contact?
- Breathing in droplets from the air
- Eating contaminated food
- Passing a pathogen in blood
- Touching a contaminated door handle
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Answer: C (1)
Question 4
Describe four ways the body defends itself against pathogens.
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- skin forms a barrier / stops pathogens entering (1)
- hairs in the nose trap pathogens / dust (1)
- mucus traps pathogens (1)
- stomach acid kills pathogens (1)
- white blood cells destroy pathogens / ingest / make antibodies (1)
- Max 4
Question 5
Explain why a clean water supply and sewage treatment are important in controlling the spread of disease.
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- water can contain pathogens / be contaminated (1)
- clean (treated) water has the pathogens removed / killed (1)
- so people do not swallow pathogens in drinking water (1)
- sewage contains pathogens (1)
- treating sewage stops it contaminating drinking water / food (1)
- Max 4
Question 6
Which action helps to stop pathogens spreading from hands to food?
- Washing hands before preparing food
- Keeping food in sunlight
- Eating food quickly
- Adding salt to water
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Answer: A (1)
Question 7
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanCholera is a disease caused by a bacterium. Explain how the cholera bacterium causes diarrhoea.
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- bacterium produces a toxin (1)
- toxin causes chloride ions to be secreted into the small intestine (1)
- water moves into the gut from the blood (1)
- by osmosis (1)
- allow Cl⁻ for chloride ions; reject chlorine / chlorine ions
- Max 4
Question 8
Explain how poor waste disposal could increase the spread of a transmissible disease.
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- waste may contain pathogens (1)
- pathogens can contaminate food / water / surfaces (1)
- people then take in the pathogens / pathogens passed to new hosts (1)
- allow animals attracted to waste spread the pathogens