A phyloGENETIC tree is not the same thing as a taxonomic tree, which is what Cal described. rRNA and molecular studies are used in phylogenetics to determine relations between species.
1 As the light intensity increases, the rate of photosynthesis increases. 2  However, the rate will not increase beyond a certain level of light intensity. 3  At high light intensities the rate becomes constant, even with further increases in light intensity, there are no increases in the rate.
Here's what a teacher thought of this essay. The experimenter gave sufficient detail on how they would investigate the effect of light intensity on the rate of photosynthesis. How variables were to be controlled or manipulated was described, however, the need to control temperature was left out.