Organelle with in an organelle is

Options

A. Ribosome
B. Lysosome
C. Chloroplast
D. DNA

Explanation

### Step-by-Step Solution:

1. **Understanding Organelles**: Begin by defining what organelles are. Organelles are specialized structures within a cell that perform distinct functions necessary for cellular activity.

2. **Identifying the Organelle Within an Organelle**: The question asks for an organelle that exists within another organelle. The key organelles to consider are chloroplasts and mitochondria, as they are known to contain their own ribosomes and DNA.

3. **Ribosomes**: Ribosomes are non-membranous organelles responsible for protein synthesis. They can be found free-floating in the cytoplasm or attached to the rough endoplasmic reticulum (RER).

4. **Rough Endoplasmic Reticulum (RER)**: The RER is an organelle that has ribosomes attached to its surface, which gives it a "rough" appearance. The ribosomes on the RER synthesize proteins that are either secreted from the cell or incorporated into the cell's plasma membrane.

5. **Chloroplasts and Mitochondria**: Both chloroplasts (found in plant cells) and mitochondria (found in both plant and animal cells) are organelles that contain their own ribosomes and DNA. This characteristic makes them unique as they can produce some of their own proteins.

6. **Conclusion**: Therefore, the organelle that is considered to be "within an organelle" is the ribosome, as it is found inside chloroplasts and mitochondria, which are themselves organelles.

### Final Answer:
The organelle within an organelle is the **ribosome**.

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