Tuesday 26 November 2013

SKELETAL SYSTEMS OF TWO EARLY TYPES OF HUMAN

Question

The diagram shows the skeletal systems of two ancestors of modern human beings.
Write a 150-word report for a university lecturer describing the diagram and making comparisons where relevant.

IELTS Comparison Diagram

Model Answer

Variations in the skeletal systems of two early types of human are illustrated in this diagram. Overall, we can see that australopithecus afarensis had a heavier body and much longer arms, while homo erectus was slimmer and had more developed joints.

To begin with the upper half of the body, australopithecus afarensis had a much broader chest and waist than homo erectus, giving it a rounder appearance. The former had much longer arms and larger hands, which would have been useful for climbing trees.

As for the lower half of the body, we can see that homo erectus had proportionately longer legs and larger hip, knee and ankle joints. The feet of homo erectus were also smaller and more arched, with shorter toes. These differences meant that homo erectus was better suited to long-distance running.

In conclusion, we can see significant changes in the development of early humans from the diagram. Homo erectus is more similar to contemporary human beings with its long legs and arched feet. The physical differences are clearly related to differences in the lifestyles of tree climbers and endurance runners.

(183 words, IELTS 8.0-C1)

 

Why does this answer get an IELTS Band 8 score-C1?

Task achievement: The model answer selects only the most important information from the diagram and uses this to make several direct comparisons. The physical differences are clearly connected to the description of each creatures’s lifestyle, providing a very rounded answer. The length is sufficient.

Coherence and cohesion: The model answer is divided into clear paragraphs with a logical separation between the body paragraphs. There is a general overview in paragraph 1 and a summary in paragraph 4. A reference link, the former, is used to avoid over-repetition of the names of the creatures.

Lexical resource: The model answer adds more vocabulary not in the diagram such as lifestyle, proportionatelysuited, appearance and contemporary. There are also attempts to paraphrase such as wide > broad and endurance > long-distance.

Grammatical range and accuracy: The model answer uses comparative structures accurately. The temptation to list all the features in repetitive structures is avoided. A variety of grammatical devices are used to extend sentences, including with, which and -ing clauses.


THE CARBON CYCLE IN NATURE

Question

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

Carbon Cycle
© The National Center for Atmospheric Research

Model Answer

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.

In short, we can see that carbon moves in a natural cycle, although human factors may now be affecting the balance.

(154 words, IELTS 8.0-C1)

 

Why does this Task 1 answer get an IELTS Band 8 score-C1?

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, thenhowever, and in short. 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.

HOW ELECTRICITY IS GENERATED BY A HYDROELECTRIC DAM

Question

The diagram shows how electricity is generated by a hydroelectric dam.
Write a 150-word report for a university lecturer explaining how the process works.


Model Answer

The diagram illustrates the basic principles of hydroelectric power. The process requires the construction of a large dam connected to a powerhouse. The dam creates a large reservoir and the powerhouse is where the electricity is generated.

First of all, water trapped in the reservoir behind the dam is forced through an intake. It then flows into a narrow chamber called a penstock, where the resulting high pressure turns a turbine. The turbine is connected to a generator in the powerhouse above, and this is where the movement of the turbine is converted into electricity. The resulting electricity leaves the powerhouse via cables that carry it over long distances to where it can be used.

It is interesting to note that a hydroelectric dam creates no harmful byproducts and relies entirely on natural forces to produce electricity. After the turbine stage, water flows out through a second channel and into a river. The process is renewable, thanks to the water cycle in nature.

(163 words, IELTS 8.0-C1)

Why does this  answer get an IELTS Band 8 score-C1?

Task achievement: The introduction paraphrases the question and describes the constituent parts of the process. The body describes each stage of the process in sequence.

Coherence and cohesion: The model answer has an introduction, body and conclusion. Sequencing expressions such as first of all, then and after are used appropriately. The articles a and the are used effectively to introduce and refer back to different elements of the process.

Lexical resource: The labels in the diagram are well integrated into the model answer and appropriate verbs such as converted, flows and leaves are used throughout. Less-common words such as byproducts and renewable are introduced by the writer. Spelling is always accurate.

Grammatical range and accuracy: The writer uses the present simple tense and has good control of subject-verb agreement and active/passive forms. A good balance of simple and complex sentences is used throughout.


CONSUMPTION OF RENEWABLE ENERGY

Question

The diagram shows the consumption of renewable energy in the USA from 1949-2008.
Write a 150-word report for a university lecturer identifying the main trends and making comparisons where relevant.

IELTS Line Graph

Model Answer

The line graph shows growth in the consumption of renewable energy during the period 1949-2008 in the USA. The results are also broken down by source.

The first thing to note is that renewable energy use more than doubled over the period, with particularly strong growth in biofuels. This sector did not exist in 1980 but experienced a steep rise during the 2000s to over one quadrillion Btu per year. This made biofuels a serious challenger to both wood and hydroelectric power, which both saw only limited growth overall. The former grew steadily between 1975 and 1985, but then slipped back to around its original level of 1.8 quadrillion Btu. The latter began the period at the same level as wood but experienced more substantial growth. However, it also fell back to around 2 quadrillion Btu, with a particularly sharp drop in the late 1990s.

Finally, wind power emerged late in the period but showed a gradual rise to around 0.5 quadrillion Btu, suggesting that it, along with biofuels, will replace wood and hydroelectricity as the main sources of renewable every in the future.

(184 words, IELTS 8.0-C1)

Why does this  answer get an IELTS Band 8 score-C1?

Task achievement: The model answer describes the overall trend first, followed by an analysis of the different energy sources. Numerical evidence is used sparingly to illustrate the trends. The main trends are used as the basis of a prediction in the final sentence.

Coherence and cohesion: Trends are explained in general terms first, followed by supporting figures. Some energy sources are grouped together for ease of understanding. It and this are used throughout as cohesive devices, and the writer uses the former and the latter to refer back to information in a previous sentence.

Lexical resource: The writer uses a wide range of vocabulary to describe change, including adjectives and adverbs such as limited, substantial and particularly sharp, and verbs such as doubled, slipped and emerged.

Grammatical range and accuracy: The model answer is free from grammatical errors. Sentence forms are complex and include relative clauses and linking words such as with. The candidate makes use of past, present and future tenses. Punctuation is also used carefully and accurately throughout.


ELECTRICITY CONSUMPTION AND EXPENSE AT A HOUSEHOLD

Question

The bar chart shows the relative electricity consumption and cost per year of various household devices.

Write a 150-word report for a university lecturer explaining the data and making comparisons where relevant.


IELTS Writing Task 1 Bar Chart

Model Answer

The bar chart compares the energy consumption and expense of operating 16 different items of household equipment. Overall, we can see significant differences in both cost and consumption.

To begin with, there are some common household items which consume relatively little energy. These include an electric blanket (approx. $10 or 100kwh/year), a microwave oven (approx. $15 or 150kwh/year) and a television (approx. $17 or 170kwh/year).

By contrast, devices that might be classified as ‘luxury’ items such as a pool pump or spa are comparatively expensive and energy-intensive, at nearly $125 or 1500kwh/year and around $190 or 2225kwh/year respectively.

It is interesting to note that even among household items normally considered alike, such as a microwave and refrigerator, there are enormous discrepancies in cost and energy use. The former uses only around $15 or 150kwh/year, while the latter consumes at least six times that amount at $90 or 1150kwh/year.

In conclusion, it appears that there is no clear pattern in the relative energy consumption of domestic equipment, although households had better be aware of the high running costs of luxury items such as a pool pump and spa.

(187 words, IELTS 8.5-C1+)

Why does this answer get an IELTS Band 8 score (C1+)?

Task achievement: The model answer presents an overall description first, followed by key supporting details that illustrate the main trend.

Coherence and cohesion: The model answer is divided into clear paragraphs and each paragraph contains one main idea. There are cohesive links between paragraphs. A variety of reference links are used throughout, including the former, the latter, and respectively.

Lexical resource: The language in the question is effectively paraphrased. Synonyms are introduced for key concepts such as electricity consumption > energy use and cost > expense. Some less-common words such as discrepancies and energy-intensive are used.

Grammatical range and accuracy: The model answer is free from grammatical errors. Sentences tend to consist of multiple clauses. Paragraphs contain a variety of sentence structures.

EXPLAINING DATA FROM DIAGRAMS AND CHARTS


Introducing the topic

  • The graph shows… / The table reveals…
  • The chart displays… / The diagram illustrates…
  • Some interesting facts concerning… are revealed in the diagram.
  • Several key trends are revealed by the graph showing…

Introducing the first set of data

  • Beginning with the…
  • To begin with the…
  • Let me begin by describing the…

Introducing the second set of data

  • Meanwhile, the…  shows that…
  • As for the… , it shows that…
  • Turning to the… , it can be seen that…

Introducing the first major trend

  • First of all, it is clear that…
  • Most noticeably of all, it can be seen that…
  • The first result worth pointing out is that…

Introducing lesser trends

  • Another trend that can be observed is that…
  • It is also worth pointing out that…
  • Also worth noting is that…

Exceptions to the main trend

  • However, this was not always the case.
  • However, it should be pointed out that…
  • There was one noticeable exception, however.

Comparing and contrasting

  • Similarly, … / By contrast, …
  • A similar trend can be observed in…
  • The results for… , however, reveal a markedly different trend.

Adding figures

  • The figures were X and Y respectively.
  • …, at X. / …, with Y. (Usage note: use ‘at’ when you mean ‘the figure was’; use ‘with’ when you mean ‘something had’)
  • …, at/with X and Y respectively.

Concluding and summarising

  • To sum up, … / In summary, … / In short, …
  • On the whole, …
  • The main thing that can be observed here is that…