Blue green algae are

Options

A. Actinomycetes
B. Eukaryotes
C. Prokaryotes
D. Acellular.

Answer

**Step-by-Step Solution:**

1. **Understanding Blue-Green Algae**: Blue-green algae are commonly referred to as Cyanobacteria. They are photosynthetic organisms that can be found in various aquatic environments.

2. **Classification**: To determine whether blue-green algae are ectomycetes, eukaryotes, prokaryotes, or acellular organisms, we need to look at their cellular structure and characteristics.

3. **Cell Structure**: Blue-green algae are classified as prokaryotic organisms. This means they lack a well-defined nucleus. Instead, they have a nucleoid region where their genetic material is located, but it is not enclosed by a nuclear membrane.

4. **Organelles**: Blue-green algae do not possess membrane-bound organelles, which is another characteristic feature of prokaryotic cells. They do, however, contain ribosomes, specifically 70S ribosomes, which are typical in prokaryotes.

5. **Examples**: Some common examples of blue-green algae include Nostoc and Anabena, which further confirm their classification as prokaryotes.

6. **Evaluating Options**:
- Ectomycetes: Incorrect, as they are fungi and not related to blue-green algae.
- Eukaryotes: Incorrect, as blue-green algae are prokaryotic.
- Prokaryotes: Correct, as blue-green algae lack a true nucleus and membrane-bound organelles.
- Acellular: Incorrect, as blue-green algae are cellular organisms.

7. **Conclusion**: Based on the above characteristics and evaluations, the correct answer is that blue-green algae are **prokaryotes**.

**Final Answer**: Blue-green algae are prokaryotes.

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