The stable condition of an organism and its internal structure as regulated by a plasma membrane is known as ________.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a term that describes the stable condition of an organism and its internal structure, which is regulated by the plasma membrane.

2. **Identifying Key Terms**: Focus on the terms "stable condition," "organism," "internal structure," and "plasma membrane." These terms suggest a biological process that maintains balance within an organism.

3. **Recalling Biological Concepts**: Consider the functions of the plasma membrane. It plays a crucial role in regulating what enters and exits the cell, thus maintaining the internal environment.

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