2.Nanoarchaeum equitans is a
unicellular
organism that
lacks a nucleus. It
is found living in
the extreme
temperatures of
hydrothermal
vents.

because of

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

the question isn't complete here so i can't right an answer '_'