Breakdown of complex molecules to yield energy takes place in

Distinguish between the following: (Any two)
$(a)$ Aerobic respiration and Anaerobic respiration
$(b)$ Glycolysis and Fermentation
$(c)$ Glycolysis and Citric acid Cycle

Select the correct option to complete the following statements:
$(1)$ The $TCA$ cycle begins with the condensation of $OAA$ and water with $Acetyl-CoA$ to yield $Citric$ $acid$.
$(2)$ In fermentation,yeast converts glucose into ethanol under $Anaerobic$ conditions.

Respiration is essential for

Given below are two statements:
Statement-$I$: Acetyl $CoA$ formation takes place by oxidative decarboxylation of pyruvic acid.
Statement-$II$: $\beta$-oxidation of fatty acid produces acetyl $CoA$.
In the light of above statements,choose the most appropriate answer from the options given below.

The term 'floating respiration' is used when the respiratory substrate is .........