Dark respiration is

Options

A. Cellular respiration
B. Found in deeper tissues and roots
C. Found only during night
D. Both B and C

Answer

**Step-by-Step Solution:**

1. **Understanding Dark Respiration**: Dark respiration refers to the process of cellular respiration that occurs in the absence of light. It is a common process that takes place in all aerobic tissues, meaning those tissues that can respire in the presence of oxygen.

2. **Location of Dark Respiration**: This process occurs in the cytoplasm and mitochondria of the cell. It is not limited to a specific time of day; rather, it can occur at any time, whether it is day or night.

3. **Process of Dark Respiration**: Dark respiration is a multi-step process that includes:
- **Glycolysis**: The first step where glucose is broken down into pyruvate, producing a small amount of ATP and NADH.
- **Krebs Cycle (Citric Acid Cycle)**: The second step where pyruvate is further broken down, releasing carbon dioxide and transferring energy to electron carriers.
- **Terminal Oxidation (Electron Transport Chain)**: The final step where oxygen is consumed, and ATP is produced through oxidative phosphorylation.

4. **Gas Exchange**: During dark respiration, oxygen is consumed primarily during the terminal oxidation phase, while carbon dioxide is released at various stages of the process.

5. **Conclusion**: Therefore, dark respiration can be defined as the cellular respiration that occurs in aerobic tissues, independent of light, and involves multiple steps including glycolysis, the Krebs cycle, and terminal oxidation.

**Final Answer**: Dark respiration is a form of cellular respiration that occurs in aerobic tissues, independent of light, and involves glycolysis, the Krebs cycle, and terminal oxidation.

---