Which is not a characteristic of mitochondria?

Options

A. Mitochondria are the sites of cellular respiration
B. Mitochondria are found in prokaryotic and eukaryotic cells
C. Mitochondria contain DNA and ribosomes
D. Inner space of the mitochondrion contains a fluid matrix

Explanation

To determine which option is not a characteristic of mitochondria, we can analyze each option provided in the question step by step.

### Step 1: Analyze the first option
- **Option 1:** Mitochondria are the site of cellular respiration.
- **Explanation:** This statement is true. Mitochondria are known as the powerhouse of the cell because they are responsible for producing ATP through cellular respiration.

### Step 2: Analyze the second option
- **Option 2:** Mitochondria are found in prokaryotic and eukaryotic cells.
- **Explanation:** This statement is false. Mitochondria are not found in prokaryotic cells; they are present only in eukaryotic cells. Prokaryotic cells lack membrane-bound organelles, including mitochondria.

### Step 3: Analyze the third option
- **Option 3:** Mitochondria contain DNA and ribosomes.
- **Explanation:** This statement is true. Mitochondria are semi-autonomous organelles that contain their own DNA and ribosomes, allowing them to produce some of their own proteins.

### Step 4: Analyze the fourth option
- **Option 4:** The inner space of mitochondria contains a fluid matrix.
- **Explanation:** This statement is true. The inner membrane of mitochondria encloses a space filled with a fluid matrix, which contains enzymes and other substances necessary for the Krebs cycle.

### Conclusion
Based on the analysis, the option that is **not a characteristic of mitochondria** is:
- **Mitochondria are found in prokaryotic and eukaryotic cells.**