Which of the following hormone helps in maintaining body temperature, metabolism, pigmentation, and defense capabilities?

Options

A. Melatonin
B. Melanin
C. Thymosis
D. Calcitonin

Answer

To solve the question regarding which hormone helps in maintaining body temperature, metabolism, pigmentation, and defense capabilities, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a hormone that plays a role in four specific functions: body temperature regulation, metabolism, pigmentation, and defense capabilities.

2. **Analyze the Options**: The options given are Melatonin, Melanin, Thymosin, and Calcitonin. We need to evaluate each option based on their functions.

3. **Evaluate Melatonin**:
- Melatonin is produced by the pineal gland.
- It regulates the sleep-wake cycle (diurnal rhythm).
- It influences body temperature, metabolism, and has roles in immune defense.
- **Conclusion**: Melatonin is a strong candidate as it relates to all four functions mentioned.

4. **Evaluate Melanin**:
- Melanin is not a hormone; it is a pigment produced by melanocytes.
- Its primary role is to protect the skin from damage due to UV radiation.
- **Conclusion**: Melanin does not fit the criteria as it does not regulate body temperature, metabolism, or defense capabilities.

5. **Evaluate Thymosin**:
- Thymosin is produced by the thymus gland.
- It plays a role in the immune system by stimulating the production of T-cells.
- **Conclusion**: While it relates to defense capabilities, it does not influence body temperature or metabolism.

6. **Evaluate Calcitonin**:
- Calcitonin is a hormone produced by the thyroid gland.
- Its main function is to regulate calcium and phosphate levels in the blood.
- **Conclusion**: Calcitonin does not relate to body temperature, metabolism, or pigmentation.

7. **Final Conclusion**: Based on the evaluations, Melatonin is the only hormone that helps in maintaining body temperature, metabolism, pigmentation, and defense capabilities.

### Answer:
**Melatonin** is the hormone that helps in maintaining body temperature, metabolism, pigmentation, and defense capabilities.

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