Explanation:
Exp:D During aerobic respiration, 2 molecules of $\mathrm{FADH}_{2}$ are produced per every glucose molecules in the kreb's cycle. The kreb cycle is the second stage of aerobic respiration and it takes place in the mitochondria.
In the kreb's cycle, pyruvate molecules from glycolysis are oxidised to carbon dioxide and water.
This process releases energy, which is used to produced ATP and NADH. FADH ${ }_{2}$ is a molecule that carries electrons from the kreb cycle to the electron transport chain. So, the total number of molecules of $\mathrm{FADH}_{2}$ produced per every glucose molecule in aerobic respiration is 2.