Theodor W Engelmann Illuminated a Filament of Algae with Light That

question 61

Multiple Choice

Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light.
-If you ran the same experiment without passing light through a prism, what would you predict?

• A) There would be no difference in results.
• B) The bacteria would be relatively evenly distributed along the algal filaments.
• C) The number of bacteria present would decrease due to an increase in the carbon dioxide concentration.
• D) The number of bacteria present would increase due to an increase in the carbon dioxide concentration.
• E) The number of bacteria would decrease due to a decrease in the temperature of the water.

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Definitions:

Circadian Rhythm

The internal process that regulates the sleep-wake cycle and repeats on each rotation of the Earth roughly every 24 hours.

Day-Night Cycle

The 24-hour period that includes one full rotation of the Earth, leading to the natural alternation between daylight and nighttime.

Seasonal Affective Disorder

A type of depression that occurs at a certain time of the year, usually during winter when there is less natural sunlight.