In 1883, Theodor W. Engelmann conducted a classic 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:

A. The bacteria have a negative phototropic response to green light and move away from it toward the blue and red regions.
B. More bacteria congregated in the red and blue light regions because they could photosynthesize more rapidly using these wavelengths of light.
C. More bacteria congregated in the red and blue light regions because these wavelengths provide the most thermal energy.
D. More bacteria congregated in the red and blue light regions because the algae in those regions produced the most oxygen.

In 1883, Theodor W. Engelmann conducted a classic experiment in which he wanted to help determine the relationship between wavelengths of light and the rate of photosynthesis. We consider that these bacteria congregated in search of the oxygen production, because when they are exposed to light, it is possible for them to produce oxygen through photosynthesis.

marianaegarciaperedo marianaegarciaperedo · Answer 2 · 2021-10-27T17:51:40+02:00

Algae photosynthesize more at red and blue light exposure. Released O₂ is used by bacteria. Option D. More Bacteria congregated in the red and blue light regions because the algae in those regions produced the most O₂.

----------------------------------------------------------------------

Different pigments are part of vegetable organisms, such as chlorophyll or carotenoids, among others.

Plants use these pigments during the photosynthesis process to absorb sunlight and fixate carbon dioxide. During this process, they release oxygen.

Tissue colors are defined by pigments on their cells.

Pigments are chemical molecules that produce color by the selective absorption of sunlight. They absorb light in certain wavelengths and reflect other wavelengths. The color expressed in tissues is due to reflection.

The green color is normal in most vegetable species. Chlorophyll is responsible for this coloration, present in almost every vegetable species.

This pigment absorbs blue and red wavelengths. But they reflect spectrums of green wavelengths, meaning that the expressed color is green in different tones.

Assuming that Engelmann used green algae in his experiment, it is expected to observe a higher photosynthetic rate when exposing the organism to red and blue wavelengths.

The higher the photosynthetic rate is, the higher levels of oxygen released there are.

This is significant because aerobic bacteria need oxygen to survive and develop.

Engelmann used aerobic, nonphotosynthetic bacteria, which were found mostly in the areas illuminated by the red and blue light.

This is not surprising since, at these wavelengths, algae released more oxygen needed by these bacteria. Besides, since they are nonphotosynthetic they were not affected by any other wavelength.

So the reasoning is as follows,

When exposed to red and blue light, algae expressed a higher photosynthetic rate

A higher photosynthetic rate means more available oxygen

Since aerobic bacteria need oxygen, they will group in areas where the molecule is abundant.

The correct option is D. More bacteria congregated in the red and blue light regions because the algae in those regions produced the most oxygen.

--------------------------------------------

Related link: https://brainly.com/question/14287100?referrer=searchResults