Which of these statements is false ?

Options

A. All prokaryotes classified under kingdom Monera have a cell wall.
B. All viroids have single - stranded RNA as the genetic material.
C. All prions don't have nucleic acid as their genetic material.
D. Unicellular plants have been place in kingdome Protista by Whittaker.

Answer

To determine which statement is false among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: All prokaryotes classified under kingdom Monera have a cell wall.**
- **Analysis:** The kingdom Monera includes all prokaryotes, which are primarily bacteria and archaea. While most prokaryotes do have a cell wall, there is an exception: mycoplasma. Mycoplasma are prokaryotic organisms that lack a cell wall, making this statement false.
- **Conclusion:** This statement is **false**.

2. **Statement 2: All viroids have a single-stranded RNA as genetic material.**
- **Analysis:** Viroids are indeed known to have a single-stranded circular RNA as their genetic material. They are smaller than viruses and do not have a protein coat. This statement is true.
- **Conclusion:** This statement is **true**.

3. **Statement 3: All prions don't have nucleic acid as their genetic material.**
- **Analysis:** Prions are infectious agents composed solely of misfolded proteins and do not contain any nucleic acids (DNA or RNA). This statement is true.
- **Conclusion:** This statement is **true**.

4. **Statement 4: Unicellular plants have been placed in kingdom Protista by Whittaker.**
- **Analysis:** According to Whittaker’s five-kingdom classification, unicellular eukaryotic organisms, including certain algae, are placed in the kingdom Protista. This statement is true.
- **Conclusion:** This statement is **true**.

### Final Answer:
The false statement is **Statement 1: All prokaryotes classified under kingdom Monera have a cell wall.**