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.
An introductory paragraph is used to hook your reader into the rest  of the essay, or making them want to read the rest of the piece of  writing. It is also used to describeâ¦ what you may be writing about,  and can occasionally be used to describe your position on a topic.   Apex To state the thesis and main topic.