The introduction should be designed to attract the reader's attention and give them an idea of the essay's focus. Following these guidelines can help you produce an effective introduction.
Describe the importance (significance) of the study: Why was this worth doing in the first place? Provide a broad context.
Defend the model: Why did you use this particular organism or system? What are its advantages? You might comment on its suitability from a theoretical point of view as well as indicate practical reasons for using it.
Provide a rationale. State your specific hypothesis and describe the reasons why you made the statement.
Very briefy describe the experimental design and how it accomplished the stated objectives.
The introduction is the broad beginning of the paper that answers three important questions:
You should answer these questions by doing the following:
Set the context. Provide general information about the main idea, explaining the situation so the reader can make sense of the topic and the claims you make and support.
State why the main idea is important. Explain to the reader why they should care about your topic and keep reading. Your goal is to create a compelling, clear, and convincing essay people will want to read and act upon.
State your thesis. Compose a sentence or two stating the position you will support with logos (sound reasoning: induction, deduction), pathos (balanced emotional appeal), and ethos (author credibility).
State the hypothesis precisely. Do not oversimplify.
Use past tense, except when referring to established
facts.
Organize your ideas, making one major point with each paragraph.
Proofread your paper. Check spelling, clarity and appropriateness of sentences and phrases.
Present background information only as needed in
order support a position.