A student is investigating cellular transport. She fills a beaker with 250 ml of water. She places 10 drops of red food coloring into the beaker of water and makes an observation immediately, after 5 minutes, and after 30 minutes. Her set up is shown below.
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The student observes that the molecules of red dye move from an area of higher concentration to an area of lower concentration until equilibrium is reached. Which best describes the type of cellular transport that the student is investigating?
a
The student is investigating the passive transport of diffusion.
b
The student is investigating the active transport of osmosis.
c
The student is investigating the active transport of diffusion.
d
The student is investigating the passive transport of osmosis.
a
The student is investigating the passive transport of diffusion.
The description of the experiment indicates that the red dye molecules move from an area of higher concentration to an area of lower concentration until equilibrium is reached. This process does not require energy and is called diffusion, which is a type of passive transport. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration along the concentration gradient until they are evenly distributed.
Osmosis, on the other hand, is a specific type of diffusion that involves the movement of water molecules across a semi-permeable membrane. Since the experiment described does not mention a semi-permeable membrane or water moving across it, osmosis is not the correct answer. Additionally, active transport requires energy to move substances against their concentration gradient, which does not align with the observed movement of molecules in the student's experiment.