In 1883, Theodor W. Engelmann conducted a classic experiment…

In 1883, Theоdоr W. Engelmаnn cоnducted а clаssic experiment in which he illuminated a filament of photosynthetic algae with light that passed through a prism, thus exposing different segments of the algae to different wavelengths of light. He then added aerobic, nonphotosynthetic bacteria, and noted that the largest groups of bacteria were found in the areas illuminated by the red and blue light. Using what you know about photosynthesis and cellular respiration, which of the following would best explain the reason for the bacteria congregating in the regions with red and blue light?