Match the components of the Electron Transport System (ETS) of aerobic respiration with their respective electron carriers.

Column I	Column II
A. Complex I	{i}Cyt c → O₂
​B. Complex II	{ii}NADH → CoQ
​C. Complex III	{iii}Succinate → CoQ
D. Complex IV	{iv}CoQH₂ → Cyt c

Correct option is A

Correct Answer: (a)

Explanation:
The correct sequence of electron flow in the mitochondrial ETS is:
NADH → Complex I → CoQ → Complex III → Cyt c → Complex IV → O₂.

Information Booster:

Complex I: NADH dehydrogenase → passes electrons from NADH to CoQ.

Complex II: Succinate dehydrogenase → passes electrons from FADH₂ (succinate) to CoQ.

Complex III: Cytochrome bc₁ complex → CoQH₂ → Cyt c.

Complex IV: Cytochrome oxidase → Cyt c → O₂ (forming H₂O).

Complexes I, III, and IV pump protons to generate ATP via oxidative phosphorylation.

Additional Information (Incorrect Options):
(b), (c), (d) — contain mismatched donor-acceptor pairs and do not align with the correct redox sequence of ETS.