Frogs are poikilothermic because body temperature 

Options

A. is maintained constant
B. varies with environmental temperature
C. keeps changing with enzymes
D. none

Answer

### Step-by-Step Solution:

1. **Understanding Poikilothermy**:
- Poikilothermic animals are those that do not maintain a constant body temperature. Instead, their body temperature fluctuates with the temperature of their environment.

2. **Characteristics of Frogs**:
- Frogs are classified as poikilothermic or cold-blooded animals. This means that their body temperature is not internally regulated but instead changes according to the external environmental conditions.

3. **Mechanism of Temperature Regulation**:
- Frogs use a process called thermoregulation to adapt their body temperature to the surrounding environment. This involves behavioral changes and physiological responses to maintain a suitable body temperature.

4. **Environmental Influence**:
- When the environmental temperature rises, frogs may seek cooler areas or water to help lower their body temperature. Conversely, when it is cold, they may bask in the sun or remain inactive to conserve heat.

5. **Conclusion**:
- Therefore, the correct explanation for why frogs are poikilothermic is that their body temperature varies with environmental temperature.

### Final Answer:
Frogs are poikilothermic because their body temperature varies with environmental temperature.

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