Question

in simple diffusion, molecules move from an area of __ concentration to an area of __ concentration.
○ equal; low
○ low; high
○ equal; high
○ low; equal
○ high; low

question 2
since the cell membrane allows some molecules to pass through it and will not allow others, it can be described as ________.
○ permeable.
○ impervious.
○ impermeable.
○ selectively permeable.
○ completely permeable.

Explanation:

For the first question, simple diffusion is the movement of molecules from an area of high concentration to an area of low concentration down the concentration gradient.
For the second question, the cell membrane allows some molecules (e.g., small non - polar molecules like oxygen) to pass through and restricts others (e.g., large polar molecules like glucose without the help of transporters). This property is called selective permeability.

Answer:

1. high; low
2. selectively permeable