Which among these is not a homeotherm ?

Options

A. Camelus
B. Calotes
C. Columba
D. Canis

Answer

To determine which among the given options is not a homeotherm, we need to understand the definition of homeotherms and analyze each option accordingly.

### Step-by-Step Solution:

1. **Define Homeotherms**:
- Homeotherms are animals that maintain a constant body temperature regardless of environmental conditions. They are commonly referred to as warm-blooded animals.

2. **Identify the Options**:
- The options provided are:
- A) Camelous (Camels)
- B) Callots (Lizards)
- C) Columbar (Pigeons)
- D) Canis (Dogs)

3. **Analyze Each Option**:
- **Camelous**: Camels are mammals and are classified as homeotherms because they can regulate their body temperature.
- **Callots**: Callots refer to lizards, which are reptiles. Reptiles are typically poikilothermic (cold-blooded), meaning their body temperature varies with the environment. Therefore, callots are not homeotherms.
- **Columbar**: Columbar refers to pigeons, which are birds. Birds are also classified as homeotherms since they maintain a stable internal body temperature.
- **Canis**: Canis includes dogs and other related mammals, which are also homeotherms.

4. **Conclusion**:
- Based on the analysis, the only option that is not a homeotherm is **B) Callots** (lizards), as they are poikilothermic.

### Final Answer:
- The correct answer is **B) Callots**.