In the context of mitochondria, why do some cells (e.g., skeletal muscle cells) contain more mitochondria than others (e.g., many adipocytes)?

• A. They have higher ATP demand, so they need greater capacity for aerobic respiration and oxidative phosphorylation.
• B. They contain more mitochondria primarily to increase storage of genetic information in mitochondrial DNA.
• C. They require more lysosomes to digest damaged organelles, so they increase mitochondrial number to supply hydrolytic enzymes.
• D. They need more mitochondria to synthesize ribosomes for protein production in the cytosol.

Answer: (A)