Use the diagram below to answer the question.
Image
The diagram shows a beaker of water and molecules of red dye at the beginning of an experiment (Time 1) and the same beaker of water and molecules of red dye after 30 minutes (Time 2). Which of the following best explains what happened?
a
Molecules of red dye moved by diffusion from a higher concentration to a lower concentration.
b
Molecules of red dye moved by active transport from a higher concentration to a lower concentration.
c
Molecules of water moved by osmosis from a lower concentration to a higher concentration.
d
Molecules of water moved by active transport from a higher concentration to a lower concentration.
a
Molecules of red dye moved by diffusion from a higher concentration to a lower concentration.
The correct answer is: a) Molecules of red dye moved by diffusion from a higher concentration to a lower concentration.
Based on the diagram, we can see that at Time 1, there is a higher concentration of red dye molecules on the left side of the beaker, and at Time 2, the molecules have spread out and become more evenly distributed throughout the beaker. This indicates that the molecules of red dye moved from a higher concentration to a lower concentration, which is characteristic of diffusion. Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration, without the need for energy or active transport mechanisms.
To answer this question, we need to understand the processes of diffusion, active transport, and osmosis, as well as observe the changes in the diagram over time.
Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. Active transport is the movement of molecules against their concentration gradient, from an area of lower concentration to an area of higher concentration, requiring energy. Osmosis is the movement of water molecules across a selectively permeable membrane, from an area of lower solute concentration to an area of higher solute concentration.
Looking at the diagram, we see molecules of red dye in a beaker of water at two different times. At the beginning of the experiment (Time 1), the red dye molecules are concentrated in one area of the beaker. After 30 minutes (Time 2), the red dye molecules are more evenly distributed throughout the beaker.
Based on this observation, the best explanation for what happened is option a: "Molecules of red dye moved by diffusion from a higher concentration to a lower concentration." Diffusion is the process by which molecules move from an area of higher concentration (Time 1) to an area of lower concentration (Time 2), resulting in a more uniform distribution of the dye molecules.
Therefore, the correct answer is option a.