Which of the following factors affects the rate of diffusion across a membrane?

• A. Color of the molecules
• B. Number of chromosomes
• C. Phase of the moon
• D. Temperature

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, driven by the concentration gradient.
2. Identify factors that influence diffusion: The rate of diffusion is affected by factors such as temperature, molecular size, concentration gradient, and the properties of the membrane (e.g., permeability).
3. Analyze the options provided: 'Color of the molecules' and 'Number of chromosomes' are not scientifically relevant to diffusion. 'Phase of the moon' is unrelated to biological processes like diffusion.
4. Focus on temperature: Temperature directly affects the kinetic energy of molecules. Higher temperatures increase molecular movement, leading to a faster rate of diffusion, while lower temperatures slow it down.
5. Conclude that temperature is the correct factor: Based on the scientific principles of diffusion, temperature is the only option provided that directly impacts the rate of diffusion across a membrane.