Band 7.5 IELTS Writing Task 1 Model Answer
Overall Band Score: 7.5 · Cambridge IELTS 19 · 2026-09-28
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 illustrates the cyclical process of producing the biofuel ethanol, and shows how carbon dioxide is both used and released at different stages.
Overall, the production of ethanol is a closed-loop system with six main stages. It begins with the growth of plants using sunlight and carbon dioxide, and ends with the use of ethanol as fuel, which in turn releases carbon dioxide back into the atmosphere to be reused by plants. The process involves both natural and industrial steps, including harvesting, pre-processing, and microbial fermentation.
In the first stage, plants and trees grow by absorbing energy from sunlight and carbon dioxide. Once mature, they are harvested using machinery. The harvested biomass then undergoes pre-processing, where it is broken down into small particles, and cellulose is extracted.
Next, the cellulose is sent for processing in an industrial facility. During this stage, it is converted into sugars. Microbes are then added to these sugars to produce ethanol through fermentation. This is the key transformation point in the cycle.
The final product, ethanol, is used as a fuel source for various forms of transport, including cars, trucks, and airplanes. A notable feature is that when ethanol is burned as fuel, it releases carbon dioxide. This carbon dioxide is then reabsorbed by growing plants, thereby completing the cycle and allowing the process to begin again.
In comparison to fossil fuels, this system is circular rather than linear because the carbon dioxide emitted during fuel use is not a net addition to the atmosphere, but is instead recycled by plants for the next round of biofuel production.
AI examiner evaluation
| Criterion | Band |
|---|---|
| Task Achievement / Task Response | 7.5 |
| Coherence and Cohesion | 7.5 |
| Lexical Resource | 7.5 |
| Grammatical Range and Accuracy | 7.5 |
| Overall | 7.5 |
Task Achievement / Task Response: Band 7.5
The student covers all parts of the task well, providing a clear overview of the cyclical process and reporting the main stages from plant growth to ethanol consumption and carbon dioxide recycling. The information is fully supported by the visual data, correctly identifying the steps such as harvesting, pre-processing, cellulose extraction, and microbial fermentation. No key stages are omitted or misread, and the response properly highlights the circular nature of the process. The student easily meets the band 8 criteria for Task Achievement by presenting a well-developed, accurate summary.
Coherence and Cohesion: Band 7.5
The response is logically sequenced and easy to follow. Ideas are organized into clear paragraphs that progress smoothly from the overall overview to the specific stages of the cycle, concluding with a comparison regarding fossil fuels. Cohesive devices such as 'In the first stage', 'Next', and 'The final product' are used naturally and effectively without being obtrusive. Paragraphing is used appropriately to separate distinct phases of the diagram, demonstrating a high level of control over textual organization.
Lexical Resource: Band 7.5
The student demonstrates a wide and flexible range of vocabulary suited to describing a scientific process. Terms such as 'cyclical process', 'closed-loop system', 'biomass', 'cellulose', 'microbial fermentation', and 'reabsorbed' are used accurately and with good stylistic awareness. Word choice and collocations are natural, and there are no noticeable spelling or word-choice errors, enabling the response to read very smoothly.
Grammatical Range and Accuracy: Band 7.5
The response exhibits a wide variety of complex sentence structures, including participial phrases ('by absorbing energy', 'thereby completing the cycle') and subordinate clauses. The majority of sentences are error-free, and grammar and punctuation are handled with a high degree of control. Minor slips are virtually absent, and the grammatical execution supports clear and sophisticated communication throughout.
See this exact question answered at other band scores. The same prompt compared across bands.
Browse more IELTS Writing model answers or get your own writing scored by the same AI examiner.