Band 7.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.5 · Cambridge IELTS 19 · 2026-10-02

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 process by which ethanol biofuel is produced from plant material and how carbon dioxide circulates throughout the cycle.

Overall, ethanol production is a cyclical process that begins with the growth of plants and trees and ends with the use of ethanol as a fuel. A key feature of the system is that the carbon dioxide released during production and consumption is reabsorbed by plants, creating a continuous cycle.

Initially, plants and trees grow by using energy from sunlight together with carbon dioxide from the atmosphere. Once mature, these crops are harvested and sent for pre-processing, during which some carbon dioxide is emitted. The plant material is then converted into cellulose, which is subsequently transported to a processing facility.

At the processing stage, cellulose is broken down into sugars. Microorganisms are then added to the sugars to facilitate fermentation, resulting in the production of ethanol. The finished biofuel is used to power various forms of transport, including cars, trucks, and aircraft.

When ethanol is burned as fuel, carbon dioxide is released into the atmosphere. Additional emissions also occur during the pre-processing stage. However, this carbon dioxide is absorbed by growing plants and trees, which use it along with sunlight to produce new biomass. As a result, ethanol production operates as a renewable cycle in which plant material is continuously converted into fuel and the emitted carbon dioxide is largely recycled.

AI examiner evaluation

Task Achievement / Task Response: Band 7.5

The response successfully addresses all parts of the task by providing a clear and comprehensive summary of the process diagram illustrating biofuel production and the carbon dioxide cycle. The overview paragraph accurately captures the cyclical nature of the system and the key role of carbon dioxide. Main features, such as the stages from plant growth and harvesting through to processing and fermentation, are clearly reported and supported with appropriate details. The progression from cellulose to sugars and ultimately to ethanol is well-traced. To reach the highest band, the response could incorporate slightly more granular data from the diagram or draw sharper comparative inferences regarding the emission points, though the current coverage is thorough and well-developed.

Coherence and Cohesion: Band 7.5

The essay displays clear logical organisation and progression throughout. Information is grouped logically by stages, and the introduction, body paragraphs, and conclusion guide the reader smoothly through the cyclical process. Cohesive devices such as 'Initially', 'Once mature', 'subsequently', and 'However' are used flexibly and appropriately to connect ideas and signal time relationships. Paragraphing is managed skilfully, with each paragraph focusing on a distinct phase of the diagram. Referencing is consistently clear, ensuring that pronouns and demonstratives point accurately to previous entities. To achieve the highest band, cohesive devices could be even more seamlessly integrated so that their mechanical appearance is entirely eliminated, though the current structure is already remarkably coherent.

Lexical Resource: Band 7.5

The writer demonstrates a sufficient and flexible range of vocabulary suited to an academic report. Less common lexical items and technical terms such as 'cyclical', 'biomass', 'fermentation', and 'reabsorbed' are used with good awareness of style and collocation. Word choices are precise, accurately reflecting the processes shown in the diagram. Spelling and word formation are entirely correct throughout the text. Minor occasional lapses in stylistic perfection prevent a higher rating, but the vocabulary is fully adequate for conveying complex scientific concepts clearly and effectively.

Grammatical Range and Accuracy: Band 8.0

The response exhibits a wide range of complex sentence structures used with a high degree of flexibility and control. The majority of sentences are entirely error-free, featuring sophisticated subordinate clauses, passive constructions, and participial phrases such as 'resulting in the production of ethanol' and 'Once mature, these crops are harvested'. Control of grammar, tense consistency, articles, and punctuation is excellent, with only very occasional minor slips that never impede communication. The writer demonstrates a strong command over complex syntactic patterns appropriate for an academic descriptive task.

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