Glycolysis is defined as

• A. ATP synthesis
• B. Glycolysis
• C. Krebs cycle
• D. Electron transport chain

Answer: (B)

Glycolysis is the breakdown of glucose into pyruvate in the cytoplasm, a pathway that generates a small amount of ATP and NADH without needing oxygen. It’s the first stage of cellular respiration and provides the substrates for later aerobic steps. Net yield is 2 ATP and 2 NADH per glucose, with pyruvate ready to enter mitochondria for the Krebs cycle if oxygen is present. Among the options, naming the process itself best fits because glycolysis is the specific pathway described; ATP synthesis is a broader term for making ATP, while the Krebs cycle and electron transport chain are later stages of respiration. So the option that corresponds to glycolysis is the best choice.