Which of the following statements about mitochondria is true?

• A. Mitochondria are found only in prokaryotic cells.
• B. Mitochondria are the primary site of ATP production in eukaryotic cells.
• C. Mitochondria contain their own DNA and ribosomes.
• D. Mitochondria are responsible for protein synthesis in the cytoplasm.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the role of mitochondria in eukaryotic cells. Mitochondria are known as the 'powerhouses' of the cell because they are the primary site of ATP production through cellular respiration.
2. Step 2: Recall that mitochondria are found in eukaryotic cells, not prokaryotic cells. Prokaryotic cells lack membrane-bound organelles, including mitochondria.
3. Step 3: Note that mitochondria contain their own DNA and ribosomes, which allow them to produce some of their own proteins independently of the cell's nucleus.
4. Step 4: Clarify that protein synthesis in the cytoplasm is carried out by ribosomes, not mitochondria. Mitochondria are not responsible for this process.
5. Step 5: Based on the above points, identify the correct statement: 'Mitochondria are the primary site of ATP production in eukaryotic cells' and 'Mitochondria contain their own DNA and ribosomes.' These are true statements about mitochondria.