Plastids are not found in

Options

A. fungi
B. bacteria
C. blue-green algae
D. all of these

Answer

To determine where plastids are not found, we need to understand what plastids are and where they are typically located.

### Step-by-Step Solution:

1. **Definition of Plastids**: Plastids are double-membrane-bound organelles found in the cells of plants and some algae. They are involved in various functions such as photosynthesis, storage, and the synthesis of other compounds.

2. **Presence in Organisms**: Plastids are predominantly found in higher plants (eukaryotes) and some protists. They are essential for processes like photosynthesis in green plants.

3. **Absence in Prokaryotes**: Prokaryotic organisms, such as bacteria, do not have plastids. This is because prokaryotes lack membrane-bound organelles.

4. **Absence in Fungi**: Fungi are also eukaryotic organisms, but they do not have plastids. Instead, they have different organelles suited for their heterotrophic mode of nutrition.

5. **Absence in Blue-Green Algae**: Blue-green algae (Cyanobacteria) are often classified as prokaryotes and do not possess plastids, although they can perform photosynthesis.

6. **Conclusion**: Since plastids are absent in prokaryotes (bacteria and blue-green algae) and in fungi, we can conclude that plastids are not found in these organisms.

### Final Answer:
Plastids are not found in prokaryotes (bacteria, blue-green algae) and fungi.