The boundaries of which of the following kingdom is not well defined ?

Options

A. Plantae
B. Fungi
C. Monera
D. Protista

Answer

To solve the question regarding which kingdom has boundaries that are not well defined, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Kingdoms**: The five kingdoms of life as proposed by R.H. Whittaker are Monera, Protista, Fungi, Plantae, and Animalia. Each kingdom has distinct characteristics.

2. **Examine Each Kingdom**:
- **Monera**: This kingdom includes unicellular organisms like bacteria, which have a cell wall made of peptidoglycan. Thus, they have a defined boundary.
- **Protista**: This kingdom is quite diverse and includes both unicellular and simple multicellular organisms. Many protists do not have a rigid cell wall, making their boundaries less defined.
- **Fungi**: Fungi have a defined cell wall made of chitin, which gives them a clear boundary.
- **Plantae**: Plants have a cell wall made of cellulose, providing a well-defined boundary.

3. **Identify the Kingdom with Undefined Boundaries**:
- Among the kingdoms, **Protista** is unique because it includes organisms that may not have a rigid cell wall, leading to less defined boundaries compared to the other kingdoms.

4. **Conclusion**: Based on the analysis, the kingdom with boundaries that are not well defined is **Protista**.

### Final Answer:
The boundaries of the kingdom that is not well defined is **Protista**.

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