Besides the big four, protoplasmic elements include

Options

A. Sulphur and Phosphorus
B. Sodium and Potassium
C. Celcium and Magnesium
D. Chromium and Selenium.

Answer

To answer the question "Besides the big four, protoplasmic elements include," we need to identify the elements that are part of protoplasm aside from the primary four elements: oxygen, nitrogen, carbon, and hydrogen.

### Step-by-Step Solution:

1. **Identify the Big Four Elements**: The big four protoplasmic elements are oxygen, nitrogen, carbon, and hydrogen. These elements make up the majority of protoplasm.

2. **Understand Protoplasmic Elements**: Protoplasm consists of two main components: nucleoplasm (inside the nucleus) and cytoplasm (between the nuclear membrane and cell membrane). Together, they contain various elements.

3. **Determine the Remaining Elements**: Besides the big four, protoplasm includes several other elements, which collectively account for about 5% of the protoplasmic composition. These include:
- Calcium
- Iron
- Magnesium
- Chlorine
- Phosphorus
- Potassium
- Sulfur

4. **Analyze the Options Given**: The options provided are:
- Sulfur and Phosphorus
- Sodium and Potassium
- Calcium and Magnesium
- Chromium and Selenium

5. **Evaluate Each Option**:
- **Sulfur and Phosphorus**: Both are known protoplasmic elements.
- **Sodium and Potassium**: Sodium is not a major protoplasmic element, making this option incorrect.
- **Calcium and Magnesium**: Both are present in protoplasm, but this option does not include elements besides the big four.
- **Chromium and Selenium**: Neither of these elements is considered a major component of protoplasm.

6. **Select the Correct Answer**: Based on the evaluation, the only option that includes elements that are indeed part of protoplasm, aside from the big four, is **Sulfur and Phosphorus**.

### Final Answer:
The correct answer is **Sulfur and Phosphorus**.