Which of the following substances is not normally found in filtrate?
a) ions, such as sodium and potassium
b) blood cells and large particles
c) nitrogenous waste particles, such as urea
d) water and small solutes

Cells a and b are the same size and shape, but cell a is metabolically quiet and cell b is actively consuming oxygen. oxygen will diffuse more quickly into cell because . b the oxygen molecules inside cell b have a higher kinetic energy b. a its membrane transport proteins will not be saturated c. a the diffusion gradient there is shallowerd. b the diffusion gradient there is steeper