The cellulosic cell wall is observed in members of

Options

A. Protista
B. Plantae
C. Both (a) and (b)
D. Monera

Answer

To solve the question "The cellulosic cell wall is observed in members of," we need to analyze the options provided and understand the characteristics of cell walls in different kingdoms of life.

### Step-by-Step Solution:

1. **Understand Cellulosic Cell Wall**:
- A cellulosic cell wall is primarily composed of cellulose, which is a polysaccharide made up of long chains of D-glucose units linked by beta-1,4-glycosidic bonds. This structure provides rigidity and strength to the cell wall.

2. **Identify Organisms with Cellulosic Cell Walls**:
- Cellulosic cell walls are predominantly found in plants. The cell wall serves various functions such as providing mechanical support, maintaining cell shape, regulating cell volume, and acting as a barrier against pathogens.

3. **Examine Other Options**:
- **Kingdom Protista**: This kingdom includes various single-celled organisms, such as diatoms and amoebas. While some protists may have cell walls, they are not primarily made of cellulose.
- **Kingdom Monera**: This kingdom includes bacteria, which have cell walls made of peptidoglycan, not cellulose.
- **Kingdom Fungi**: Fungi have cell walls made of chitin, which is different from cellulose.

4. **Conclusion**:
- Based on the analysis, the only kingdom that contains organisms with cellulosic cell walls is **Kingdom Plantae**.

### Final Answer:
The cellulosic cell wall is observed in members of **Kingdom Plantae**.

---