All of the following pairs are homologous EXCEPT Question 5 options:

a cat's forelimb and a human's arm

a human's arm and a bird's wing

a bird's wing and a butterfly's wing

a bird's wing and a whale's flipper

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