Question 1

The ratio of the volume of CO₂ evolved to O₂ consumed in respiration is called the:

Accepted Answer

Respiratory Quotient (RQ). RQ = volume of CO₂ released / volume of O₂ used, and depends on the respiratory substrate.

Question 2

When carbohydrates are the respiratory substrate, the RQ is:

Accepted Answer

1.0. For carbohydrates (e.g. glucose), CO₂ produced = O₂ consumed, so RQ = 1.

Question 3

For fats as the respiratory substrate, the RQ is:

Accepted Answer

Less than 1 (about 0.7). Fats need more O₂ (they are less oxidised), giving RQ ≈ 0.7.

Question 4

The amphibolic nature of the respiratory pathway means it:

Accepted Answer

Serves in both breakdown (catabolism) and synthesis (anabolism). Respiratory intermediates (e.g. acetyl CoA, OAA) are drawn off to synthesise fats, amino acids, etc. — hence amphibolic.

Question 5

An RQ greater than 1 (or approaching infinity) is characteristic of ______ respiration:

Accepted Answer

Anaerobic (fermentation, where CO₂ is released without O₂ uptake). In anaerobic respiration CO₂ is released while O₂ is not consumed, so RQ > 1 (or infinite).

Question 6

The assumptions in the standard respiratory balance sheet (38 ATP) include all EXCEPT:

Accepted Answer

Glycolysis, TCA and ETS pathways operate at different times in a stepwise sequential manner. In reality the pathways occur simultaneously and are not neatly sequential, so the 38-ATP figure is a theoretical maximum.

Respiratory Balance Sheet & RQ — NEET Biology MCQs with Solutions

Questions with solutions