Which characteristic is true for both reptiles and birds?

Which characteristic is true for both reptiles and birds?

• A. Lungs
• B. Warm-blooded
• C. Feathers
• D. Scales

Answer: (A)

Both reptiles and birds rely on lungs as their primary organ for gas exchange, providing the essential surface area for oxygen in and carbon dioxide out to support their activity and metabolism. Birds do have an especially efficient system with air sacs that keep air flowing through the lungs, but the core shared feature is the presence of lungs. Warm-bloodedness is characteristic of birds rather than reptiles, so it isn’t shared. Feathers are unique to birds, and reptiles have scales, so those traits aren’t common to both.

Both reptiles and birds rely on lungs as their primary organ for gas exchange, providing the essential surface area for oxygen in and carbon dioxide out to support their activity and metabolism. Birds do have an especially efficient system with air sacs that keep air flowing through the lungs, but the core shared feature is the presence of lungs. Warm-bloodedness is characteristic of birds rather than reptiles, so it isn’t shared. Feathers are unique to birds, and reptiles have scales, so those traits aren’t common to both.