The diagram below illustrates the carbon cycle in nature.Write a 150-word description of this diagram for a university lecturer.

Sample Answer 1:
The diagram shows how carbon moves through various stages to form a complete cycle. This report will give a brief description of the main stages in this cycle.
First, we can see that energy from the sun is transformed into organic carbon through a process in plants known as photosynthesis. This organic carbon is then transferred underground when plants, and the animals that feed on them, die and decay. Some of this carbon is trapped underground in the form of fossils and fossil fuels.
Carbon is also released back into the atmosphere, however, through various means. One is when animals and plants respire, and another is when humans burn fossil fuels in cars and factories. All this carbon enters the atmosphere as CO2. It is then reabsorbed by plants, and the cycle begins again.
Overall, we can see that carbon moves in a natural cycle, although human factors may now be affecting the balance.
(154 words, IELTS 8.0)

Why does this Task 1 answer get an IELTS Band 8 score?
Task achievement: The model answer selects and describes most components of the diagram except for waste products and ocean uptake. There is an overall description of the cycle followed by a clearly sequenced and divided description of the stages. The summary identifies something noteworthy about the diagram. The length is sufficient.
Coherence and cohesion: The model answer is divided into clear paragraphs with a logical separation between the body paragraphs and connective markers first, then, however, and overall. There is a general overview in paragraph 1 and a summary in paragraph 4. Referencing techniques such as ellipsis (one is…) are used to avoid over-repetition of key words.
Lexical resource: The writer makes good use of the language in the diagram and is also able to change forms in the case of respiration respire. The writer also introduces a range of verbs for describing a process or cycle such as transform, transfer and release.
Grammatical range and accuracy: The model answer demonstrates accurate usage of a wide range of forms including countable/uncountable nouns, active/passive structures, and transitive/intransitive verbs.