Which of the following describes the gas exchange that occurs in the lungs?
a carbon dioxide enters the body, while oxygen leaves the body.
b oxygen and carbon dioxide both enter the body.
c oxygen enters the body, while carbon dioxide leaves the body.
d oxygen and carbon dioxide both leave the body.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

kelp are large brown algae that live in cool, relatively shallow waters close to the shore. they grow in dense groupings much like a forest on land. these underwater towers of kelp provide food and shelter for thousands of fish, invertebrates, and marine mammal species.

e) all of the above