Which statement is scientifically based?
a. mutations rarely occur.
b. all mutations are harmful.
c. some mutations can be contagious, like infections.
d. mutations are not passed from parent to offspring.

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