The branch of biology that deals with the study of interactions between organisms and their environment is termed

Options

A. evolution
B. ecology
C. ethology
D. etiology

Answer

To answer the question, "The branch of biology that deals with the study of interactions between organisms and their environment is termed," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Question**: The question asks for the specific branch of biology that focuses on the interactions between organisms and their environment.

2. **Review the Options**: The options provided are:
- Evolution
- Ecology
- Ethology
- Etiology

3. **Define Each Option**:
- **Evolution**: This refers to the change in heritable characteristics of biological populations over successive generations. It does not focus specifically on interactions with the environment.
- **Ecology**: This is the study of organisms and how they interact with their environment and each other. This directly relates to the question.
- **Ethology**: This is the study of animal behavior, which may involve interactions but is not focused on the environment as a whole.
- **Etiology**: This is the scientific study of the causes of diseases, which is unrelated to the interactions between organisms and their environment.

4. **Select the Correct Answer**: Based on the definitions, the correct answer is **Ecology**, as it specifically studies the interactions between organisms and their environment.

5. **Conclude**: Therefore, the branch of biology that deals with the study of interactions between organisms and their environment is termed **Ecology**.

### Final Answer:
**Ecology**