Using data about risk factors

Organisation · Animal tissues, organs and organ systems · note 19 of 20

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Using data about risk factorsSpec 4.2.2.6

In short

Using risk factor data means interpreting charts, tables and scatter diagrams that link a risk factor to a disease. First describe what the data show, then say whether there is a correlation. A correlation alone does not prove that the risk factor causes the disease; you also need a causal mechanism, and a large, representative sample.

You need to interpret data about risk factors for specified diseases. The same skills apply as for incidence data.

Translate information between graphical and numerical forms.
Extract and interpret information from charts, graphs and tables.
Use a scatter diagram to identify a correlation between a risk factor and a disease.
Understand sampling: the sample should be large and representative for the conclusion to be reliable.

Describe what the data show first, then say whether there is a correlation. Then say whether the data prove a cause. A correlation alone does not. You also need a causal mechanism, or evidence that other factors were controlled.

Common mistake:

Do not write ‘this proves that smoking causes cancer’ from a scatter diagram. Write that the data show a correlation.

Written and checked against the AQA GCSE Biology (8461) specification · Updated October 2026

Frequently asked questions

Why do enzymes denature at high temperatures?

At high temperatures the shape of the enzyme's active site changes, so the substrate no longer fits and the reaction cannot be catalysed. The enzyme is denatured, and this cannot be changed back. Below the optimum, the rate rises with temperature because particles move faster and collide more often. Enzymes are not killed, because they are not alive.

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Millions of alveoli give a very large surface area for diffusion. Their walls are one cell thick, so the diffusion distance is short. A network of capillaries carries oxygen away and brings carbon dioxide, and constant ventilation brings fresh air. Both keep a steep concentration gradient, so oxygen diffuses into the blood and carbon dioxide diffuses out quickly.

Why is the left ventricle thicker than the right?

The left ventricle has a thicker muscular wall than the right because it pumps blood all the way around the body at a higher pressure. The right ventricle only pumps blood to the lungs. Both are part of the double circulatory system, in which blood passes through the heart twice on each complete circuit.

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