"Cell within the Cell" is stated for mitochondria and chloroplasts.

Answer

### Step-by-Step Solution:

1. **Understanding the Concept of "Cell within the Cell":**
- The phrase "cell within the cell" refers to the unique characteristics of mitochondria and chloroplasts, which are organelles found in eukaryotic cells.

2. **Identifying the Characteristics of Mitochondria and Chloroplasts:**
- Both mitochondria and chloroplasts have a double membrane structure. This means they are surrounded by two layers of membranes, similar to the structure of a cell.

3. **Presence of DNA:**
- Mitochondria and chloroplasts contain their own DNA. This is significant because it is a characteristic of living organisms, suggesting that these organelles have some level of autonomy.

4. **Ribosomes and Protein Synthesis:**
- These organelles also have their own ribosomes and the machinery necessary for protein synthesis. This further supports the idea that they can function independently to some extent.

5. **Semi-Autonomous Organelles:**
- Because of the above characteristics, mitochondria and chloroplasts are often referred to as semi-autonomous organelles. They can carry out some functions independently but still rely on the cell for others.

6. **Comparison to the Nucleus:**
- In a similar way, the nucleus of a cell also contains DNA and has its own protein-synthesizing machinery. The nucleus coordinates the activities of the cell, much like how mitochondria and chloroplasts contribute to the cell's energy production and photosynthesis.

7. **Conclusion:**
- Therefore, the term "cell within the cell" aptly describes mitochondria and chloroplasts because they possess characteristics similar to those of a cell, including their own DNA, ribosomes, and double membranes.