Question

which of the following statements regarding respiratory rate is false? a when carbon dioxide levels rise, we breathe more rapidly to expel the excess. b respiratory rate is regulated by the level of carbon dioxide in the blood. c when carbon dioxide levels fall, we breathe more rapidly to bring in more. d medical conditions like pneumonia or brain injury will affect respiratory rate.

Explanation:

The body's respiratory rate is regulated by carbon - dioxide levels in the blood. When CO₂ levels rise, we breathe faster to expel the excess (A is true). The level of CO₂ in the blood does regulate respiratory rate (B is true). Medical conditions such as pneumonia or brain injury can affect respiratory rate (D is true). However, when carbon - dioxide levels fall, we breathe more slowly, not more rapidly, to retain CO₂.

Answer:

C. When carbon dioxide levels fall, we breathe more rapidly to bring in more.