Many Types of Plants Increase the Number of Stomata Per

Multiple Choice

Many types of plants increase the number of stomata per unit surface area of a leaf when atmospheric carbon dioxide levels decline. Which of the following is an analogous response in humans?

A) breathing faster as atmospheric carbon dioxide levels increase
B) putting more red blood cells into circulation when oxygen availability declines at high elevations
C) breathing more slowly as atmospheric oxygen levels increase
D) increasing the volume of its lungs when atmospheric carbon dioxide levels increase