What is the purpose of crossing-over in meiosis? A. to create mutations in gametes to increase variation
B. to randomly separate homologous chromosome pairs
C. to reduce the number of chromosomes in gametes by one half
D. to create new combinations of DNA on homologous chromosomes

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