The rate of diffusion of a molecule into a cell is affected by which of the following factors?

• A. The phase of the moon
• B. The color of the molecule
• C. The gravitational pull on the molecule
• D. The concentration gradient of the molecule

Answer: (D)

Verified step by step guidance

1. Understand the concept of diffusion: Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. This process is driven by the concentration gradient, which is the difference in concentration between two areas.
2. Identify the factors that affect diffusion: The primary factor affecting the rate of diffusion is the concentration gradient. A steeper gradient (greater difference in concentration) results in a faster rate of diffusion.
3. Consider other factors that might influence diffusion: While the concentration gradient is the main factor, temperature and the size of the molecules can also affect the rate of diffusion. Higher temperatures increase the kinetic energy of molecules, speeding up diffusion, while larger molecules may diffuse more slowly.
4. Evaluate the options given in the problem: The phase of the moon, the color of the molecule, and the gravitational pull on the molecule do not directly affect the rate of diffusion. These factors are not related to the concentration gradient or the physical properties of the molecules involved in diffusion.
5. Conclude with the correct factor: The concentration gradient of the molecule is the correct factor that affects the rate of diffusion into a cell. This is because diffusion is driven by the movement of molecules from areas of high concentration to areas of low concentration.