Which ones do not have cellular structure

Options

A. PPLO
B. Rickettsia
C. Viruses
D. Archaebacteria

Answer

To determine which option does not have a cellular structure, we can analyze each of the given choices:

1. **PPLO (Mycoplasma)**:
- Mycoplasma is a type of bacteria and is considered the smallest living organism. It has a cellular structure, even though it lacks a cell wall. Therefore, it is a living entity with cellular organization.

2. **Rickettsia**:
- Rickettsia are also bacteria, specifically a genus of bacteria that are obligate intracellular parasites. They have a cellular structure and are classified as living organisms.

3. **Viruses**:
- Viruses are unique entities that do not have a cellular structure. They are composed of genetic material (either DNA or RNA) surrounded by a protein coat, and they cannot carry out metabolic processes on their own. They are considered non-living because they require a host cell to replicate and do not exhibit characteristics of living cells.

4. **Archaebacteria**:
- Archaebacteria are a group of microorganisms that are similar to bacteria but have distinct genetic and biochemical differences. They possess a cellular structure and are classified as living organisms.

Based on this analysis, the option that does not have a cellular structure is:

**Answer: C. Viruses**

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