In what cell organelle does cellular respiration primarily occur?

• A. Chloroplast
• B. Nucleus
• C. Ribosome
• D. Mitochondrion

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the process of cellular respiration. Cellular respiration is the process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.
2. Step 2: Recall the primary organelle responsible for energy production in eukaryotic cells. This organelle is often referred to as the 'powerhouse of the cell.'
3. Step 3: Learn the structure and function of the mitochondrion. The mitochondrion has a double membrane, with the inner membrane folded into structures called cristae, which increase the surface area for reactions involved in cellular respiration.
4. Step 4: Understand that cellular respiration primarily occurs in the mitochondrion. Specifically, the Krebs cycle (citric acid cycle) occurs in the mitochondrial matrix, and the electron transport chain occurs along the inner mitochondrial membrane.
5. Step 5: Compare the mitochondrion to other organelles listed in the problem (chloroplast, nucleus, ribosome). Chloroplasts are involved in photosynthesis, the nucleus houses genetic material, and ribosomes synthesize proteins. None of these are directly involved in cellular respiration.