When birds breathe, the air passes over the lungs once. Whyis this more efficient than in mammals where air passes over thelungs twice – on the way in and on the way out? (1 point)

11 What specialized organ do mammals have for respiration? (0.5points) 1

2 Are human young altricial or precocial? Explain. (1 point)

Answer rating: 100% (QA)

Efficiency of Bird Respiration Birds have a highly efficient respiratory system where air passes ove... View the full answer