Question

Animal cells are suspended in a culture medium that contains excess glucose. The graph below shows glucose utilisation under different growth conditions. (A), (B), and (C) in the graph indicates.

• A. A- Anaerobic respiration
  B- Introduction of $O_2$ to culture medium
  C- Aerobic respiration
• B. A- Aerobic respiration
  B- Introduction of ${CO}_2$ to culture medium
  C- Anaerobic respiration
• C. A- Aerobic respiration
  B- Supply of organic triphosphate
  C- Aerobic respiration
• D. A- Aerobic respiration
  B- Introduction of CO to culture medium
  C- Anaerobic respiration

Answer 1

Answer: (A)

A- Anaerobic respiration

B- Introduction of $O_2$ to culture medium
C- Aerobic respiration
Anaerobic respiration takes place in the absence of oxygen. It leads to incomplete degradation of substrate into alcohol and ${CO}_2$ releasing some energy (2ATP). Thus, the time between A-B is aerobic respiration as there is very less production of ATP. After introduction of $O_2$ at B point, the organism initiate aerobic respiration. It results in complete oxidation of substrate into ${CO}_2$, water and energy (38 ATP). The B-C region is having incremental production of ATP. Thus, B-C region is of Aerobic respiration.

So, the correct answer is (A).