Which of the following essential mineral nutrient is the constitutent of ring structure of chlorophyll ?

Options

A. Manganese
B. Magnesium
C. Calcium
D. Potassium

Answer

To determine which essential mineral nutrient is a constituent of the ring structure of chlorophyll, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Chlorophyll**:
- Chlorophyll is a green pigment found in plants that plays a crucial role in photosynthesis. It contains a complex structure, including a ring of pyrrole units.

2. **Identify the Key Components**:
- The chlorophyll molecule consists of a porphyrin ring, which is made up of pyrrole rings. In the center of this ring, there is a metal ion that is essential for its function.

3. **Recognize the Importance of Magnesium**:
- The central metal ion in the chlorophyll structure is magnesium (Mg). This is critical because magnesium helps in the absorption of light and is essential for the photosynthetic process.

4. **Eliminate Other Options**:
- Other mineral nutrients such as manganese, calcium, and potassium do not form part of the chlorophyll structure. Therefore, they can be ruled out as constituents of the chlorophyll ring.

5. **Conclude the Correct Answer**:
- Based on the above analysis, the essential mineral nutrient that is a constituent of the ring structure of chlorophyll is magnesium.

### Final Answer:
The essential mineral nutrient that is a constituent of the ring structure of chlorophyll is **Magnesium (Mg)**.

---