The ratio of the volume of `CO_(2)` evolved to the volume of `O_(2)` consumed in respiration is called

Options

A. Respiratory ratio
B. Respiratory quotient
C. Respiratory extinction value
D. Both (1) & (2)

Answer

To solve the question regarding the ratio of the volume of CO₂ evolved to the volume of O₂ consumed in respiration, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the term used to describe the ratio of carbon dioxide (CO₂) produced during respiration to the oxygen (O₂) consumed.

2. **Identify the Key Terms**: The key terms in the question are "volume of CO₂ evolved" and "volume of O₂ consumed".

3. **Define the Concept**: In biological terms, this ratio is known as the "respiratory quotient" (RQ). It is a measure used to assess the efficiency of respiration and the type of substrate being metabolized.

4. **Recognize Synonyms**: The respiratory quotient is also referred to as the "respiratory ratio" or "respiratory exchange ratio". All these terms essentially refer to the same concept.

5. **Consider the Options**: The options provided in the question include:
- Respiratory ratio
- Respiratory quotient
- Respiratory extinction value
- Both 1 and 2

6. **Eliminate Incorrect Options**:
- "Respiratory extinction value" is not a recognized term in this context, so it can be eliminated.
- The terms "respiratory ratio" and "respiratory quotient" are both correct.

7. **Select the Correct Answer**: Since both "respiratory ratio" and "respiratory quotient" are correct, the best answer would be "Both 1 and 2".

### Final Answer:
The ratio of the volume of CO₂ evolved to the volume of O₂ consumed in respiration is called the **respiratory quotient** (or respiratory ratio).

---