Refer to the table below showing data collected from chloroplasts isolated from spinach leaves.The chloroplasts were incubated with either compound Q or Z, or with no additions in the control.After 30 minutes of incubation, chloroplasts were analyzed for the photosynthetic functions shown in the table. Assume that compounds Q and Z directly affect components involved in the light reactions.What do these data indicate about the relationship between the light reactions and the light-independent reactions?
A) The light-independent reactions can occur even if the light reactions are inhibited by chemical agents.
B) If a subset of the light reactions is functional, that is sufficient for the light-independent reactions to also be functional.
C) At least one of the products of the light reactions is essential in enabling the light-independent reactions to run.
D) Chemical agents can reverse the sequence of the light reactions and the light-independent reactions.
E) Light reactions and light-independent reactions can be induced to reverse their dependency on light by the actions of chemical agents.

Question

Refer to the table below showing data collected from chloroplasts isolated from spinach leaves.The chloroplasts were incubated with either compound Q or Z, or with no additions in the control.After 30 minutes of incubation, chloroplasts were analyzed for the photosynthetic functions shown in the table.  Assume that compounds Q and Z directly affect components involved in the light reactions.What do these data indicate about the relationship between the light reactions and the light-independent reactions?
A) The light-independent reactions can occur even if the light reactions are inhibited by chemical agents. 
B) If a subset of the light reactions is functional, that is sufficient for the light-independent reactions to also be functional. 
C) At least one of the products of the light reactions is essential in enabling the light-independent reactions to run. 
D) Chemical agents can reverse the sequence of the light reactions and the light-independent reactions. 
E) Light reactions and light-independent reactions can be induced to reverse their dependency on light by the actions of chemical agents.

Quizplus · Accepted Answer

The data indicate that both compounds Q and Z inhibit the photosynthetic functions that rely on the light reactions, but the light-independent reactions (measured by CO2 uptake) are not affected by the absence of these compounds. This suggests that at least one of the products of the light reactions is necessary for the light-independent reactions to occur. Therefore, choice C is the best answer.

Refer to the Table Below Showing Data Collected from Chloroplasts