Health and environment
Health and environment

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Health and environment

9 course questions

course Question A

Foxes eat rabbits and rabbits eat dandelions. Predict what will happen if rabbit numbers are severely reduced (e.g. by disease). How confident are you about your predictions?


A simple prediction is that dandelions will flourish and the number of foxes will decline. The reduction in fox numbers in relation to rabbit numbers might resemble the predator–prey relationship shown in Figure 4. However, you should not be too confident of this prediction because it is rare for simple food chains to operate in isolation (feeding relationships between organisms are more realistically represented as food webs (e.g. Figure 2). In fact, when rabbit numbers were reduced by myxomatosis in the UK during the 1950s, the number of foxes did not decline but owl numbers did. This is because foxes can eat a varied diet, including insects, fruit, berries and also voles, and voles are the owl's main food source.

course Question B

In the UK there are some substances that it is illegal to own or use. List arguments for and against banning the sale of tobacco. Are there any reasons why a ban is unlikely?


Arguments for a ban:

  1. The smoke from tobacco contains pollutants that are causally implicated as cancer-causing agents (carcinogens).

  2. Smoking increases risk of cardiovascular disease.

  3. The particulate matter in smoke can cause respiratory disorders such as bronchitis and emphysema.

  4. Tobacco smoke in an enclosed atmosphere affects the respiratory tract of non-smokers too.

  5. Babies born to mothers who smoke during pregnancy are smaller and more susceptible to disease than normal. Also the risk of miscarriage is much higher for smokers than non-smokers.

Arguments against a ban:

  1. Claims made about the adverse effects of tobacco smoke on human health are based on epidemiological studies, not on evidence gained from direct experimentation on humans.

  2. Individuals have the right to make their own health choices.

  3. There is the possibility that useful substances might be obtained from the tobacco plant; a total ban on tobacco sales would therefore be undesirable.

The revenue from the tax on tobacco and also the considerable individual fortunes that rest on the tobacco industry might make a ban on all sales unlikely. From general knowledge you probably realize that the financial, social and scientific issues that relate to the use of tobacco are very complex.


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