In which cycle do we rely on bacteria

nitrogen cycle

Explanation:

Nitrogen enters the living world by way of bacteria and other single-celled prokaryotes, which convert atmospheric nitrogen— N 2 \text N_2 N2start text, N, end text, start subscript, 2, end subscript—into biologically usable forms in a process called nitrogen fixation.

a

explanation:

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