Answer:
a. <u>A</u><u> describes the effect of light intensity on photosynthesis.</u>
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 <u><em>the intensity increases steadily, so does the rate</em></u>- 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 <em>carbon dioxide or the temperature</em> limits the reaction. For instance, at high intensities tissues may even be damaged by high temperatures or heat.