Biology CLEP Prep Practice Exam

What is the role of nitrogen in the ecological cycle?

1. To store energy

2. To act as a catalyst

3. To improve cell structure

4. To act as a nutrient

The correct answer is: To act as a nutrient

Nitrogen plays a crucial role in the ecological cycle as it is an essential nutrient for all living organisms. It is a major component of proteins and DNA, which are essential for the growth and development of organisms. Option A, storing energy, is incorrect because nitrogen is not a primary source of energy for organisms. Option B, acting as a catalyst, is incorrect because nitrogen does not speed up chemical reactions. Option C, improving cell structure, is incorrect because nitrogen does not directly contribute to the physical structure of cells.