Basic essay structure
The body of an essay is where you develop your essay. This occurs in a series of paragraphs with each paragraph logically flowing to the next. Thus
The first sentence of each paragraph, often referred to as a topic sentence, introduces the paragraph by stating and summarising the main point being made in the paragraph. Topic sentences often contain transition signals (signposts) which aid in the smooth transition from one paragraph to the next. This first sentence should inform the reader of the point you are making and how this paragraph relates to the question. In fact, if the reader were to scan your topic sentences, they should be able to obtain a sketch of the entire essay. This sketch should show the logical progression of the points you are making. Absence of topic sentences leaves the reader wondering what you are trying to say and why, ultimately confusing the reader.
Signposting is not limited to topic sentences. Signposting within your paragraph also aids the reader. The following example well illustrates the effective use of signposts (bolded).
Finally, as with all models of learning, information processing has limitations. For example, the model implies that thinking and learning occur in a serial (linear) processing form, whereas we know that thinking and learning are more complex than this (it is a recursive process). Furthermore, the model fails to take into account motivation, emotions and social interaction as elements affecting learning processes. Nevertheless, the model gives teachers many useful starters for considering how information can be structured to facilitate learning.
Ref: The University of New England http://www.une.edu.au/tlc/alo/paragraph7.htm
Effective paragraphs have three important qualities.
In addition to a topic sentence and supporting sentences, body paragraphs, often but not always, have a concluding sentence. The topic sentence introduces the paragraph, and the concluding sentence summarises it. However, this concluding sentence is not essential. What is important is that the transition from one paragraph to the next is logical and well signalled.