Biological mass, which constitutes both plants and animals is called —

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes the biological mass made up of both plants and animals.

2. **Identifying Key Terms**: The key terms in the question are "biological mass," "plants," and "animals."

3. **Recalling Relevant Concepts**: In the study of energy sources, biological mass is often associated with renewable energy sources derived from living or recently living organisms.

...