When the immune system detects a pathogen in the body, the cells respond

a. autosomal.

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

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;