question_subject:
question_exam:
stats:
keywords:
The correct sequence of events in cellular respiration in higher plants is option 4 - 3, 1, 2.
1. Glycolysis: This is the first step in cellular respiration, where glucose molecule is broken down into two molecules of pyruvate. It takes place in the cytoplasm and does not require oxygen.
2. Citric Acid Cycle (also known as the Krebs cycle or the TCA cycle): After glycolysis, pyruvate enters the mitochondria and undergoes further breakdown in the presence of oxygen. This cycle produces energy-rich molecules such as NADH and FADH2.
3. Electron Transport System: The NADH and FADH2 molecules generated in the previous steps transport electrons to the electron transport chain in the inner mitochondrial membrane. This chain is made up of protein complexes that transfer the electrons, producing a large amount of ATP (adenosine triphosphate) - the main energy currency of the cell.
Therefore, the correct sequence is 3, 1, 2.