Answer:
a. A describes the effect of light intensity on photosynthesis.
Step-by-step explanation:
In plants and other primary producers, photosynthesis is a biological mechanism that is vital to energy production. Energy-containing carbohydrates are derived from light, water and carbon dioxide in the form of glucose molecules.
The waste product oxygen is released as a result. Photosynthesis depends on many variables, including:
- carbon dioxide concentration,
- ambient temperature
- and light intensity
It is a rate-limited reaction. Since photons or particles of light provide the energy required for the reaction, high intensities of light increase the photosynthetic rate. From the graph shown, as the intensity increases steadily, so does the rate- but at too high of an intensity, it ceases to affect the rate of photosynthesis, which becomes constant or plateaus.
Beyond this point, either the supply of carbon dioxide or the temperature limits the reaction. For instance, at high intensities tissues may even be damaged by high temperatures or heat.