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 osmosis.
b
The student is investigating the active transport of osmosis.
c
The student is investigating the passive transport of diffusion.
d
The student is investigating the active transport of diffusion.
c
The student is investigating the passive transport of diffusion.
c) The student is investigating the passive transport of diffusion.
The student in this scenario is investigating the passive transport of diffusion.
To arrive at this conclusion, we can break down the experiment and its results. The student placed 10 drops of red food coloring into the beaker of water. Initially, the red dye molecules are concentrated in one area (the drops) and are not evenly distributed throughout the water.
When observing immediately, after 5 minutes, and after 30 minutes, the student notices that the red dye molecules gradually spread out and move from an area of higher concentration (the drops) to an area of lower concentration (the rest of the water). Eventually, the concentration of red dye throughout the water reaches equilibrium, meaning it is evenly distributed.
This movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached is known as diffusion. Diffusion is a type of passive transport because it does not require the input of energy. Instead, it occurs spontaneously as molecules move down their concentration gradient.
Therefore, the correct answer is c) The student is investigating the passive transport of diffusion.