Health and Disease

1. 1 State [1 mark]

   State what is meant by a non-communicable disease.

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   Model answer

   A disease that is not caused by a pathogen and cannot be passed from one person to another.

   Mark scheme

   • Not caused by a pathogen / cannot be passed on — 1 mark
2. 2 Give [2 marks]

   Give two examples of non-communicable diseases.

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   Model answer

   Any two of: coronary heart disease, cancer, type 2 diabetes, emphysema (lung disease).

   Mark scheme

   • First example — 1 mark
   • Second example — 1 mark
3. 3 Explain [2 marks]

   Explain why a person with HIV is more likely to suffer from other infections.

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   Model answer

   HIV damages the white blood cells of the immune system. The immune system can then no longer defend the body against other pathogens.

   Mark scheme

   • HIV damages the immune system / white blood cells — 1 mark
   • Cannot fight other pathogens — 1 mark
4. 4 Describe [3 marks]

   Describe three ways in which different types of disease can interact.

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   Model answer

   A defect in the immune system makes infectious diseases more likely. Viruses that live in cells can trigger cancers. An immune reaction started by a pathogen can trigger allergies such as asthma. (Also accept: severe physical illness can lead to depression.)

   Mark scheme

   • A first correct interaction — 1 mark
   • A second correct interaction — 1 mark
   • A third correct interaction — 1 mark
5. 5 Describe [2 marks]

   A scatter diagram shows that as the amount of salt in the diet increases, blood pressure also increases. Describe the correlation and state whether it proves that salt causes high blood pressure.

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   Model answer

   It is a positive correlation. It does not prove cause, because there may be other factors, so further evidence is needed.

   Mark scheme

   • Positive correlation — 1 mark
   • Does not prove cause / other factors — 1 mark
6. 6 Explain [3 marks]

   A study of the link between a disease and diet uses a sample of 20 people. Explain why a larger sample would give more reliable results.

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   Model answer

   A larger sample is more likely to represent the whole population. It reduces the effect of unusual individuals and chance, so a pattern found is more likely to be real.

   Mark scheme

   • Larger sample more representative — 1 mark
   • Reduces the effect of chance / unusual individuals — 1 mark
   • Results are more reliable — 1 mark
7. 7 Explain [4 marks]

   Explain how health can be affected by both physical and mental factors, giving one example of how each type of ill health can lead to the other.

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   Model answer

   Health is a state of physical and mental well-being, so both matter. Severe physical ill health, such as a long-term illness, can lead to depression or other mental illness. Mental stress can also affect physical health, for example by making a person less able to resist infection, because life situations and stress have a profound effect on physical health.

   Mark scheme

   • Health means physical and mental well-being — 1 mark
   • Physical illness can lead to mental illness — 1 mark
   • Stress or life situations can affect physical health — 1 mark
   • A relevant example — 1 mark

Quick check

1. 1

   Which of these is a communicable disease?

   1. ACoronary heart disease
   2. BType 2 diabetes
   3. CMeasles
   4. DLung cancer
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   C: Measles

   Measles is caused by a virus and can be passed from one person to another.

2. 2

   Which of these is a non-communicable disease?

   1. AMalaria
   2. BCancer
   3. CSalmonella food poisoning
   4. DGonorrhoea
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   B: Cancer

   Cancer is not caused by a pathogen, so it cannot be passed on.

3. 3

   How does HIV make other infections more likely?

   1. AIt makes the skin thinner
   2. BIt destroys red blood cells
   3. CIt makes the lungs smaller
   4. DIt damages the immune system
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   D: It damages the immune system

   HIV attacks the white blood cells of the immune system, so the body cannot fight other pathogens.

4. 4

   What type of correlation shows one variable falling as the other rises?

   1. ANegative
   2. BPositive
   3. CNone
   4. DCausal
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   A: Negative

   When one variable increases and the other decreases, the correlation is negative.

5. 5

   Which statement about a correlation is correct?

   1. AIt proves that one factor causes the other
   2. BIt is always positive
   3. CIt shows a link but not necessarily a cause
   4. DIt cannot be shown on a graph
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   C: It shows a link but not necessarily a cause

   A correlation shows that two things are linked, not that one causes the other.

6. 6

   Why is a large sample better than a small sample?

   1. AIt is cheaper
   2. BIt is more likely to be representative
   3. CIt is quicker to collect
   4. DIt avoids the need for a graph
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   B: It is more likely to be representative

   A large sample is more likely to represent the whole population.

7. 7

   Which virus can trigger cervical cancer?

   1. AHPV
   2. BThe measles virus
   3. CTobacco mosaic virus
   4. DSalmonella
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   A: HPV

   Some types of human papillomavirus (HPV) can trigger cervical cancer.

8. 8

   Which of these is an example of severe physical ill health affecting mental health?

   1. AA virus triggering a cancer
   2. BA rash caused by an allergy
   3. CA bacterium making toxins
   4. DDepression following a serious illness
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   D: Depression following a serious illness

   Severe physical illness can lead to depression and other mental illness.