Which of the following are the three main stages of cellular respiration?

The three main stages of cellular respiration are glycolysis, the Krebs cycle, and the electron transport chain. This process is essential for cells to convert glucose into usable energy in the form of ATP.

Glycolysis occurs in the cytoplasm and is the first step of cellular respiration, where glucose is broken down into two molecules of pyruvate, producing a net gain of ATP and NADH in the process.

Following glycolysis, the Krebs cycle (also known as the citric acid cycle or TCA cycle) takes place in the mitochondria. Here, the pyruvate is further broken down, releasing carbon dioxide and transferring high-energy electrons to carrier molecules, NADH and FADH2, which will be used in the next stage.

The final stage is the electron transport chain, which occurs across the inner mitochondrial membrane. In this stage, the electrons carried by NADH and FADH2 are transferred through a series of proteins, creating a proton gradient that drives the synthesis of ATP through oxidative phosphorylation.

This sequence of processes—glycolysis followed by the Krebs cycle and then the electron transport chain—is crucial for aerobic respiration, making option B the accurate representation of the stages involved in cellular respiration.