Just like a food chain, energy enters the food web at the trophic level of the producers, which can also be called autotrophs. In the desert, autotrophs are often some type of cactus, grass, or shrub.
The main purpose of the INTRODUCTION is to give a description of the problem that will be addressed. In this section the researcher might discuss the nature of the research, the purpose of the research, the significance of the research problem, and the research question(s) to be addressed. Three essential parts of a good introduction are: RATIONALE.
Writing Introductions. The introduction is the first sentence of your essay and it plays the dual role of setting the theme of your essay and engaging the reader. The introduction should not be overly formal. You do not want an admissions officer to start reading your essay and think, here we go again..