Which of the following is not a stage of cellular respiration?

The Calvin cycle is not a stage of cellular respiration; it is part of photosynthesis. This cycle occurs in the chloroplasts of plant cells, where it uses carbon dioxide and energy obtained from sunlight to produce glucose. In contrast, the stages of cellular respiration—glycolysis, the Krebs cycle, and the electron transport chain—occur in the mitochondria of cells and are focused on breaking down glucose to generate ATP, the primary energy currency of the cell. Glycolysis is the first step, breaking down glucose into pyruvate; the Krebs cycle processes pyruvate to produce electron carriers; and the electron transport chain uses these carriers to generate ATP, culminating in the production of water. Understanding the distinction between photosynthetic processes and cellular respiration is essential in biology, as they reflect different metabolic pathways.