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.
The Purpose of the Constitution of the United States Introduction. The United States Constitution is the oldest and the shortest written constitution in the world. Its 4,400 words have played a crucial role in limiting government and creating freedom for over 200 years.