Question

A bird's respiratory system is more efficient than that of other land vertebrates because ______________

A) it has larger lungs than other land vertebrates.
B) it relies on gills for respiration.
C) air flows through the lungs in only one direction.
D) it lacks a diaphragm for breathing.

Answer 1

Birds have a more efficient respiratory system than other land vertebrates because of their unidirectional airflow through the lungs and the presence of air sacs.

Step-by-step explanation:

Birds have a unique respiratory system that is more efficient than that of other land vertebrates because air flows through their lungs in only one direction. This unidirectional airflow allows for a more efficient exchange of gases, as oxygen can be extracted more effectively from the inhaled air. Additionally, the presence of air sacs in birds helps to lighten their body and provides a larger surface area for gas exchange.