Final answer:
B) O2. The terminal electron acceptor of the electron transport chain is oxygen (O2), which combines with electrons and hydrogen ions to form water at the end of the chain, enabling ATP production.
Step-by-step explanation:
Oxygen, represented by option B, is the terminal electron acceptor of the electron transport chain in aerobic respiration. During the electron transport chain, electrons are transferred from NADH and FADH2 to a series of protein complexes. These electrons gradually lose energy and are finally accepted by oxygen, which combines with hydrogen ions to form water.
The terminal electron acceptor of the electron transport chain is oxygen (O2). In the process of aerobic respiration, electrons are passed along the chain and energy is released which is used to form ATP. At the end of this chain, oxygen accepts these electrons in combination with hydrogen ions to form water (H2O).
Why oxygen? Oxygen is essential because it has a strong affinity for electrons and is very electronegative. Without oxygen to accept the electrons, the electron transport chain would come to a halt, ATP production would cease, and the cell would die from a lack of energy. This is why organisms that rely on aerobic respiration must continuously intake oxygen.