The gritty nature of diatomaceous earth is due to:

Options

A. Silica in the cell wall
B. Ability to photosynthesize
C. Calcium in the cell wall
D. Excess salt in the cell from the sea

Answer

To solve the question regarding the gritty nature of diatomaceous earth, we can break it down into several steps:

### Step-by-Step Solution:

1. **Understanding Diatomaceous Earth**:
- Diatomaceous earth is a sedimentary rock that is primarily composed of the fossilized remains of diatoms, which are a type of algae.

2. **Composition of Diatoms**:
- Diatoms have a unique cell wall made of silica (silicon dioxide). This silica gives diatoms their structural integrity and is a key component of diatomaceous earth.

3. **Formation of Diatomaceous Earth**:
- When diatoms die, their silica-rich cell walls accumulate on the ocean floor or other water bodies. Over millions of years, these accumulated remains form layers of diatomaceous earth.

4. **Gritty Nature Explained**:
- The term "gritty" refers to a rough or coarse texture. The presence of silica in the form of tiny particles contributes to this gritty texture. The accumulated silica from the diatoms resembles sand, which is why diatomaceous earth has a gritty feel.

5. **Conclusion**:
- Therefore, the gritty nature of diatomaceous earth is due to the presence of silica in the cell walls of diatoms, which, upon their death and accumulation, forms this rough-textured sedimentary rock.

### Final Answer:
The gritty nature of diatomaceous earth is due to the presence of silica in the cell walls of diatoms.

---