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.
Write an introduction that interests the reader and effectively outlines your arguments. Every essay or assignment you write must begin with an introduction. It might be helpful to think of the introduction as an inverted pyramid. In such a pyramid, you begin by presenting a broad introduction to the topic and end by making a more focused point about that topic in your thesis statement. The introduction has three essential parts, each of which serves a particular purpose.