The diagram below shows the nitrogen cycle.
Write a report for a university lecturer describing the information shown below.
Nitrogen moves in a cycle through the air, plants and animals and the soil, and back into air. The action of lighting and free-living nitrogen-fixing bacteria carries the nitrogen into the soil. At the same time some nitrogen-fixing bacteria in the nodules of leguminous plants take the nitrogen directly from the air. The nitrogen in the soil is taken up by non-leguminous green plants, while leguminous plants derive nitrogen directly from the bacteria in the nodules. Both types of plants are consumed by animals. Then, when the animals and plants die, or the animals excrete their food, the nitrogen is returned to the soil, where it is acted on by denitrifying bacteria. These cause the nitrogen to be returned to the air, and the cycle continues.
|Test tip:The vocabulary will mostly be closely related to the special subject matter being shown, and so you cannot prepare for that. There are, however, two aspects of the language that you will require for describing most diagrams and you should make sure that you know how to use them well:
1)The verbs will normally be in the present tense and the passive form.
2)Where a process or structure is being presented, you will need a variety of connectors showing stages or time.