1) Urea moves out of the liver cells into the blood plasma by diffusion. Describe how this happens.
2) how is it possible for oxygen to move from the alveolus into the capillary and why is this important?
3) how is it possible for carbon dioxide to move from the capillary into the alveolus and why is this important

you don't have to answer all at once but please answer asap :)

Abiology teacher asks students to give examples of genetic variations that support the idea that changes in a population’s environment affect genetic variation. which is the least supportive example? a.changes in genetics in human populationsb.antibiotic resistance in bacteria populationsc.pesticide resistance in garden insectsd.changes in the color of the peppered moth population in england