Answer: ozone concentration
Explanation: The Dobson Unit is the most common unit for measuring ozone concentration. Becuse ozone concentration is hard to measure they use The Dobson Unit.
Answer: Directional selection occurs when individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other. ... Directional selection does the “heavy lifting” of evolution by tending to move the trait mean toward the optimum for the environment.
Carbon accumulates oxygen
