Which graph represents selection that may lead to reduced variation in a population? Proportion of individuals
Trait Value
= Original population
= Population after selection
duals

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

air enters through the nose, moves through the nasal cavity, the pharynx, the larynx, enters the trachea, moves through the bronchi andbronchioles till the alveoli.