Bacteria and blue-green algae are similar due to the (

Options

A. Presence of mitochondria
B. Chemosynthetic mode of nutrition
C. Presence of flagella
D. Presence of nucleoid

Answer

To determine the similarity between bacteria and blue-green algae (cyanobacteria), we need to analyze the options provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding the Organisms**:
- Bacteria and blue-green algae are both classified as prokaryotes. This means they lack a true nucleus and membrane-bound organelles.

2. **Evaluating the Options**:
- **Option A: Presence of Mitochondria**:
- Prokaryotes, including both bacteria and blue-green algae, do not have mitochondria as they lack membrane-bound organelles. Therefore, this option is incorrect.

- **Option B: Chemosynthetic Mode of Nutrition**:
- Bacteria can be chemosynthetic or heterotrophic, while blue-green algae primarily utilize photosynthesis to produce their own food. Since their modes of nutrition differ, this option is also incorrect.

- **Option C: Presence of Flagella**:
- Some bacteria have flagella for movement, but blue-green algae do not possess flagella. Thus, this option is incorrect as well.

- **Option D: Presence of Nucleoid**:
- Both bacteria and blue-green algae have a nucleoid region, which is a non-membrane-bound area where the genetic material is located. This is a characteristic feature of prokaryotes, making this option correct.

3. **Conclusion**:
- The similarity between bacteria and blue-green algae lies in the presence of a nucleoid. Therefore, the correct answer is **Option D: Presence of Nucleoid**.

### Final Answer:
**Option D: Presence of Nucleoid**

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