Final answer:
Cellular respiration occurs in all living cells and involves glycolysis, Krebs cycle, and oxidative phosphorylation. Glycolysis does not require oxygen and occurs in the cytoplasm, while the other two stages require oxygen and occur in the mitochondria.
Step-by-step explanation:
Cellular respiration occurs in the cells of all living things, both autotrophs and heterotrophs. It involves three stages: glycolysis, the Krebs cycle, and oxidative phosphorylation. Glycolysis does not require oxygen and takes place in the cytoplasm, while the Krebs cycle and oxidative phosphorylation require oxygen and occur in the mitochondria.