What is the part of dna that codes for a functional protein? a- gene b- exon c- intron d- polypeptide

It's exon. Just took the test.

an adaptation is a change or process by which an organism takes to be better suited for its environment. for example; migration is a behavioral adaptation, this is needed because birds are not built to last extremely cold climates. there are different adaptations because there are different species needing to adjust to different things, bears don't migrate; they hibernate.

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