Function of thyrocalcitonin is `:-`

Options

A. To reduce the calcium level in blood
B. To increase the calcium level in blood
C. Oppose the action of thyroxine
D. Maturation of gonads

Answer

### Step-by-Step Solution:

1. **Identify the Hormone**: The question asks about the function of thyrocalcitonin, also known as calcitonin (TCT).

2. **Source of the Hormone**: Thyrocalcitonin is secreted by the thyroid gland, which is located on either side of the trachea.

3. **Type of Hormone**: It is classified as a peptide hormone, which means it is made up of amino acids.

4. **Function of Thyrocalcitonin**: The primary function of thyrocalcitonin is to regulate calcium levels in the blood.

5. **Mechanism of Action**: Thyrocalcitonin works to decrease the calcium levels in the blood. It does this by promoting the deposition of calcium in the bones, thus facilitating bone formation.

6. **Evaluate the Options**: Given the options:
- Option A: Reduce the calcium level in blood (Correct)
- Option B: Increase the calcium level in blood
- Option C: Oppose the action of thyroxine
- Option D: Maturation of gonads

7. **Conclusion**: The correct answer is Option A, as thyrocalcitonin functions to reduce the calcium level in the blood.