Figure 10.3
-Referring to Figure 10.3, oxygen would inhibit the CO₂ fixation reactions in
A) cell I only.
B) cell II only.
C) neither cell I nor cell II.
D) both cell I and cell II.
E) cell I during the night and cell II during the day.

Question

Figure 10.3
-Referring to Figure 10.3, oxygen would inhibit the CO₂ fixation reactions in
A) cell I only. 
B) cell II only. 
C) neither cell I nor cell II. 
D) both cell I and cell II. 
E) cell I during the night and cell II during the day.

Quizplus · Accepted Answer

In Figure 10.3, we can see that cell II has special adaptations to minimize the amount of oxygen that reaches the CO₂ fixation reactions. Specifically, it has a C₄ carbon fixation pathway and bundle sheath cells that provide an extra barrier to prevent oxygen from reaching the CO₂ fixation enzyme (RuBisCO). Therefore, oxygen would inhibit the CO₂ fixation reactions in cell II only.

Figure 10.3 -Referring to Figure 10.3, Oxygen Would Inhibit the CO₂ Fixation