Question

1 multiple choice 1 point passive diffusion is when a drug travels across the cell membrane from an area of ____ concentration to an area of ____ concentration. high; high high; low low; high low; low 2 multiple choice 1 point drugs can cross the cell membrane by which of the following mechanisms? facilitated diffusion mediated diffusion assisted diffusion active diffusion 3 multiple choice 1 point

Explanation:

Question 1

Passive diffusion is a process where substances move across a membrane without energy input, following the concentration gradient (from high to low concentration). So the correct pair is high to low.

Facilitated diffusion is a valid mechanism for drugs (and other molecules) to cross cell membranes, using transport proteins. Mediated diffusion is not a standard term, assisted diffusion is incorrect, and active diffusion is a misnomer (active transport requires energy, diffusion is passive). So facilitated diffusion is correct.

Answer:

B. high; low

Question 2