Which element is constituent of biotin?

Options

A. calcium
B. phosphorus
C. sulphur
D. Megnesium

Answer

To determine which element is a constituent of biotin, we need to analyze the options provided: Calcium, Phosphorus, Sulphur, and Magnesium.

### Step-by-Step Solution:

1. **Understanding Biotin**: Biotin, also known as Vitamin B7, is a water-soluble vitamin that plays a crucial role in various metabolic processes, including the metabolism of fats, carbohydrates, and proteins.

2. **Analyzing the Options**:
- **Calcium**: This is a macronutrient essential for plant growth and development, primarily involved in cell division and cell wall synthesis. However, it is not a constituent of biotin.
- **Phosphorus**: Another macronutrient, phosphorus is vital for the formation of nucleic acids and energy transfer (ATP). While important for plant health, it is not a component of biotin.
- **Sulphur**: This element is found in two amino acids, cysteine and methionine. Methionine is known to be a precursor for several coenzymes and vitamins, including biotin. Thus, sulphur is indeed a constituent of biotin.
- **Magnesium**: This is also a macronutrient that plays a role in photosynthesis and enzyme function but is not a component of biotin.

3. **Conclusion**: Based on the analysis, the correct answer is **Sulphur** as it is the element that constitutes biotin.

### Final Answer:
The element that is a constituent of biotin is **Sulphur**.