In the organization of life, is the most inclusive level.

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

correct answer is a. and d.

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.