Band 6.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 6.5 · Cambridge IELTS 19 · 2026-10-03

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 6.5)

The image illustrates a continuous cycle for the production of Biofuel (Ethanol) involving 9 stages.

Overall, the biofuel production process is a continuous cycle consisting of 9 stages in which Sunlight and carbon dioxide help plants and trees grow, which are further processed to form ethanol that emits carbon dioxide later on when ethanol is burned, which serves as the input for this cycle at the start.

In the first stage, sunlight and carbon dioxide help the plants and trees to grow that are harvested in the 2nd stage and are pre-processed using machines in the 3rd stage to form Cellulose in the 4th.

The cellulose is taken through an industrial process in the 5th stage to produce sugars in the 6th. Now, Microbes are added to the Sugars in the 7th stage, which results in Ethanol in the 8th stage. Finally, Ethanol is burned in vehicles such as cars, trucks, etc to emit carbon dioxide in the 9th stage which combines with sunlight and serves as the input and continues this cycle.

AI examiner evaluation

Task Achievement / Task Response: Band 6.5

The response successfully addresses all parts of the task by outlining the main features of the biofuel production cycle. An overview is provided right at the beginning, summarizing the continuous nature of the process and its key inputs and outputs. However, certain aspects are slightly mechanical and under-developed, relying heavily on a step-by-step numbering approach rather than fully synthesising the relationships between the stages. While all critical steps from sunlight and plants to harvesting, pre-processing, cellulose, processing, sugars, microbes, and ethanol are mentioned, the explanation of how carbon dioxide acts as the linking bridge between the combustion in vehicles and plant growth could be more thoroughly integrated. This positions the response comfortably within the mid-range for task achievement, where relevant information is presented, but some stages lack depth and fuller extension.

Coherence and Cohesion: Band 6.5

The response demonstrates a coherent overall arrangement with a clear logical progression from the initial stages of plant growth through to the final combustion of ethanol. Paragraphing is utilized, separating the introduction, overview, and body paragraphs effectively. Cohesive devices are employed to guide the reader through the sequence, such as 'In the first stage', 'The cellulose is taken', and 'Finally'. However, the cohesion occasionally feels a bit mechanical, particularly with the repetitive reliance on numerical markers like 'in the 2nd stage', 'in the 3rd stage', and 'in the 4th'. Referencing is generally clear, though some sentences run on slightly, such as the lengthy overview sentence, which could benefit from tighter segmentation to improve overall flow and readability.

Lexical Resource: Band 6.0

The vocabulary used is adequate for the task, successfully conveying the sequence and processes shown in the diagram with terms such as 'continuous cycle', 'pre-processed', 'cellulose', 'industrial process', and 'combust'. The student makes attempts at less common vocabulary items like 'microbes' and 'emits', though there is some minor inaccuracy in word choice and collocation, such as referring to the biological growth as 'energy (sunlight + carbon dioxide) help plants and trees to grow'. Spelling is generally accurate throughout the response. To reach a higher band, the writer needs to incorporate a wider range of sophisticated, less common lexical items with greater precision and natural collocation when describing scientific and industrial processes.

Grammatical Range and Accuracy: Band 6.0

The response displays a mix of simple and complex sentence forms, attempting relative clauses and participial phrases, such as 'which results in Ethanol in the 8th stage' and 'which combines with sunlight and serves as the input'. There are some errors in grammar and punctuation, such as missing articles ('help plants and trees to grow that are harvested') and slight prepositional or punctuation slips around vehicle lists ('cars, trucks, etc to emit'). Nevertheless, these errors rarely impede communication, and the meaning remains clear throughout. The grammar control is consistent with a level that handles basic structures well and attempts complex sentences, though persistence of minor structural slips prevents a higher rating.

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

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