RQ value depends on

Options

A. Type of respiratory substrate
B. Type of oganism
C. Presence of light
D. Absence of 'CO_2'

Answer

To determine what the RQ (Respiratory Quotient) value depends on, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of RQ**:
- RQ is defined as the ratio of the volume of carbon dioxide (CO2) produced to the volume of oxygen (O2) consumed during respiration.
- The formula is:
\[ RQ = \frac{\text{Volume of CO2 produced}}{\text{Volume of O2 consumed}} \]

2. **Identify Factors Affecting RQ**:
- The RQ value can vary based on several factors, which include:
- The type of respiratory substrate (e.g., carbohydrates, fats, proteins).
- The type of organism (e.g., plants, animals).
- The conditions under which respiration occurs (e.g., presence of light, absence of CO2).

3. **Analyze Each Option**:
- **Type of Respiratory Substrate**: This is a significant factor. Different substrates yield different amounts of CO2 and consume different amounts of O2.
- **Type of Organism**: This can also influence RQ, as different organisms may utilize substrates differently.
- **Presence of Light**: This primarily affects photosynthesis rather than respiration, so it is not a direct factor for RQ.
- **Absence of CO2**: This would not typically affect the RQ value directly, as RQ is a measure of the relationship between CO2 produced and O2 consumed.

4. **Conclusion**:
- The RQ value primarily depends on the type of respiratory substrate used in the process of respiration. Thus, the correct answer is that RQ value depends on the **Type of respiratory substrate**.

### Final Answer:
The RQ value depends on the **Type of respiratory substrate**.

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