Answer: Mitochondria.
- A Nucleus
- B Ribosome
- C Mitochondria
- D Endoplasmic reticulum
Correct answer: C. Mitochondria
Explanation: The majority of ATP is produced in mitochondria during aerobic respiration (oxidative phosphorylation).
Animal cell structure with major organelles labeled. Image: LadyofHats (Mariana Ruiz), Public Domain, via Wikimedia Commons.
Concept context
Cell theory, prokaryotic vs eukaryotic cells, organelles and their functions. Foundation of all biology.