Which process in plants is directly affected by light intensity?

Photosynthesis is the process in plants that is directly influenced by light intensity because it relies on light energy to convert carbon dioxide and water into glucose and oxygen. Specifically, in the chloroplasts of plant cells, chlorophyll absorbs light energy, which then powers the photosynthetic reactions. With increased light intensity, the rate of photosynthesis generally increases, up to a certain point, as there are more photons available to be absorbed.

Essentially, light provides the energy necessary for the light-dependent reactions of photosynthesis, where ATP and NADPH (energy carriers) are produced. This energy is then utilized in the Calvin cycle (light-independent reactions) to synthesize sugar. If light intensity is low, the rate of photosynthesis will be limited because fewer photons are available to drive the reactions, which clearly illustrates the direct relationship between light intensity and photosynthesis in plants.

While respiration, transpiration, and fermentation are important processes in plants, they do not have the same direct dependency on light intensity as photosynthesis does. Respiration occurs continuously in the presence of oxygen and does not rely on light conditions. Transpiration is affected by environmental factors such as humidity and temperature but not directly by light intensity. Fermentation occurs anaerobically and is not