The structure of the Luis model follows the text structure described in the source material.
Explanation:
The source material indicate that an informative essay should be structured into 3 main sections as follows:
Introduction: Hook your reader’s interest and clearly identify your subject. Make your topic and main point clear.
Body: Discuss each main idea in one or more paragraphs and support each main idea with facts, examples, and quotations.
Conclusion: Bring your essay to a close by tying your ideas together. Summarize or restate your main idea(s) or draw conclusions.
As the Luis model, clearly begins with the definition of the problem, which is further enhanced by the comparison of two species in the body and than there is a generalized conclusion in the end for completion of the essay.