Band 7.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.5 · Cambridge IELTS 19 · 2026-09-22

IELTS Writing Task 1 question

 

The diagram below shows how a biofuel called ethanol is produced.

Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

Student answer (Band 7.5)

The diagram outlines the basic steps of producing ethanol, a type of biofuel.

In general, the process involves physical, chemical, and biological treatments to produce ethanol from trees and plants. Ethanol is then used as an alternative to fossil fuels to reduce pollution.

At the beginning of the six-stage process, plants and trees absorb carbon dioxide and sunlight from the atmosphere. A process called photosynthesis helps convert these two ingredients into energy, which directly contributes to the growth of these plants and trees. As they reach maturity, people harvest them using machinery. The harvested products will undergo a pre-processing process, which breaks them down into strands of cellulose by crushing. With the help of chemicals, these cellulose strands are further deconstructed into different sugar molecules.

After the aforementioned physical and chemical treatment steps, these sugar molecules are then biologically processed. Microbes are added to convert the sugars into ethanol, which in turn is used as a fuel to power vehicles with combustion engines such as cars, trucks, and planes. These vehicles burn up the ethanol, releasing carbon dioxide as waste into the atmosphere. The trees and plants, in turn, consume this as their food, and the cycle restarts.

AI examiner evaluation

Task Achievement / Task Response — Band 7.5

The student covers all parts of the diagram well, providing a clear and accurate summary of the biofuel production process from start to finish. The overview successfully captures the main features of the cycle, noting that it involves physical, chemical, and biological treatments. Key stages such as photosynthesis, harvesting, pre-processing into cellulose, chemical deconstruction into sugars, and biological conversion using microbes are reported logically and are fully grounded in the provided visual data. There are no major omissions or misinterpretations of the source diagram, making this a well-developed response.

Coherence and Cohesion — Band 8.0

Ideas are logically sequenced and the progression of the cyclical process is easy to follow. Paragraphing is used appropriately, with a clear introduction and overview followed by well-structured body paragraphs detailing the specific steps. Cohesive devices are managed skilfully, utilizing linking phrases such as 'In general', 'At the beginning of', and 'After the aforementioned physical and chemical treatment steps' to guide the reader smoothly through the text without mechanical transitions.

Lexical Resource — Band 7.5

The student demonstrates a wide and flexible lexical range suitable for an academic task. Words and phrases like 'photosynthesis', 'deconstructed', 'biologically processed', and 'combustion engines' are used naturally and with a good awareness of academic style and collocation. There are only very minor stylistic repetitions, such as 'process' in 'pre-processing process', but overall the vocabulary is precise and contributes significantly to the clarity of the response.

Grammatical Range and Accuracy — Band 7.5

The response features a wide range of complex structures used accurately and flexibly. Examples include participial phrases and relative clauses, such as 'which breaks them down into strands of cellulose by crushing' and 'vehicles with combustion engines such as cars, trucks, and planes'. The majority of sentences are error-free, with excellent control of punctuation, tense consistency, and subject-verb agreement throughout the essay.

See this exact question answered at other band scores — the same prompt compared across bands.

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