In Carl Woese's classification system, the domain that includes the blue-green algae, nitrogen-fixing bacteria and mycoplasma i

Options

A. Bacteria
B. Eukarya
C. Monera
D. Archaea

Answer

To answer the question regarding Carl Woese's classification system and the domain that includes blue-green algae, nitrogen-fixing bacteria, and mycoplasma, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Carl Woese's Classification System**: Carl Woese proposed a three-domain system of classification based on genetic information, particularly the sequences of ribosomal RNA (rRNA). This system categorizes all living organisms into three main domains: Archaea, Eukarya, and Bacteria.

2. **Identify the Organisms Mentioned**: The question specifically mentions blue-green algae, nitrogen-fixing bacteria, and mycoplasma.
- Blue-green algae (also known as cyanobacteria) are photosynthetic bacteria.
- Nitrogen-fixing bacteria are a group of bacteria that convert atmospheric nitrogen into a form usable by plants.
- Mycoplasma are a type of bacteria that lack a cell wall.

3. **Classify the Organisms**: All three of these organisms fall under the category of bacteria.
- Blue-green algae are classified as cyanobacteria, which are part of the domain Bacteria.
- Nitrogen-fixing bacteria are also classified under the domain Bacteria.
- Mycoplasma are classified as bacteria as well.

4. **Determine the Correct Domain**: Since all the mentioned organisms (blue-green algae, nitrogen-fixing bacteria, and mycoplasma) are classified under the domain Bacteria, the answer to the question is the domain Bacteria.

### Final Answer:
The domain that includes blue-green algae, nitrogen-fixing bacteria, and mycoplasma is **Bacteria**.