Biology

the phenomenon that is not likely to occur immediately in its chloroplasts is that the fixation of CO₂ increases.

Although the Calvin cycle can continue for a short time without light, the lack of ATP and NADPH from the light-dependent reactions will soon inhibit the overall Calvin cycle. As the reduction of C₃ compounds is blocked due to the lack of ATP and NADPH, the Calvin cycle will slow down, and the fixation of CO₂ will not increase but rather decrease over time.

The other options are likely to occur:

Option A: This is likely to happen immediately. In the light-dependent reactions of photosynthesis, ATP and NADPH are produced, which are then used in the Calvin cycle for CO₂ fixation. Without light, the light-dependent reactions stop, leading to a decrease in ATP and NADPH production. As a result, the Calvin cycle (which fixes CO₂...