Metabolic rate is lowest in frog when it is

Options

A. Floating upon water surface
B. Sleeping underground
C. Quietly waiting for a prey
D. Resting upon ground

Answer

**Step-by-Step Solution:**

1. **Understanding Metabolic Rate**: Metabolic rate refers to the rate at which an organism converts food into energy. It can vary based on the organism's activity level and environmental conditions.

2. **Identifying the States of Frogs**: Frogs can be in various states, such as active (hunting or moving), resting, or in a dormant state (hibernation or estivation).

3. **Defining Hibernation**: Hibernation is a state of inactivity and metabolic depression in endotherms. For frogs, this typically occurs during colder months when they sleep underground to avoid freezing temperatures.

4. **Metabolic Rate During Hibernation**: During hibernation, frogs enter a state where they do not feed and their body functions slow down significantly. This leads to the lowest metabolic rate.

5. **Energy Source During Dormancy**: Even though frogs do not feed during hibernation, they have energy reserves stored in their fat bodies. These reserves provide the necessary nutrients to sustain them during this inactive period.

6. **Evaluating Other Options**:
- **Floating on Water Surface**: This state does not lead to the lowest metabolic rate as frogs are still somewhat active.
- **Waiting for Prey**: This is also an active state, where the metabolic rate remains higher.
- **Resting on Ground**: While resting, frogs are still somewhat active, leading to a higher metabolic rate than during hibernation.

7. **Conclusion**: The metabolic rate is lowest in frogs when they are sleeping underground, as this signifies hibernation, where they are in an inactive state and rely on their fat reserves.

**Final Answer**: Metabolic rate is lowest in frogs when it is sleeping underground.

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