A student is investigating cellular transport. They fill a beaker with 250 ml of water. The student then places 10 drops of red food coloring into the beaker of water and makes an observation immediately, after 5 minutes, and after 30 minutes. The student's set up is shown.
Three beakers contain water molecules and dye molecules. The first beaker is labeled 'Adding the dye' and shows the dye molecules closely packed in a circle. The second beaker is labeled 'After 5 minutes' and the dye molecules are starting to move apart. The third beaker is labeled 'After 30 minutes' and the dye molecules are evenly dispersed within the water molecules.
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 active transport of diffusion.
B.
The student is investigating the active transport of osmosis.
C.
The student is investigating the passive transport of osmosis.
D
.
The student is investigating the passive transport of diffusion.
D. The student is investigating the passive transport of diffusion.
D. The student is investigating the passive transport of diffusion.
The student is investigating the passive transport of diffusion.
Explanation:
Diffusion is the passive movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached. In this case, the red dye molecules are moving from an area of higher concentration (when they were added to the water) to an area of lower concentration (when they spread out evenly within the water). Active transport, on the other hand, requires energy to move substances against their concentration gradient. Osmosis is a specific type of diffusion that involves the movement of water molecules across a semipermeable membrane. However, since the question does not mention the presence of a membrane, it can be concluded that the student is investigating the passive transport of diffusion. Therefore, option D is the correct answer.