Identify the event(s) that form part of the Calvin cycle. Light energy is absorbed by a pigment molecule. Protons (H+) are moved against their concentration gradient. Carbon dioxide (CO2) is incorporated into a preexisting sugar molecule. ATP and NADPH are produced.

Carbon dioxide (CO2) is incorporated into a preexisting sugar molecule.

Explanation:

Photosynthesis is a metabolic process undergone by the cells of autotrophic organisms in order to synthesize their own food. The photosynthetic process occurs I two stages viz: light-dependent stage and light-independent stage. The light dependent stage produces the energy (ATP) and reducing agent (NADPH) needed for the second stage.

The light-independent stage, also called Calvin Cycle, is the second stage of the photosynthetic process. The Calvin cycle is the stage where the glucose sugar (food) is synthesized. The very first phase of the Calvin cycle involves the fixation of Carbondioxide (CO2) by a CO2 acceptor called Ribulosbiphosphate (RUBP), as catalyzed by RUBISCO.

Hence, Carbon dioxide (CO2) is incorporated into a preexisting sugar molecule represents the event that form part of the Calvin cycle. Other options are part of the light stage.