The chromosome structure in a cell accounts for
genetic variation based on the order of its
a. sugar groups
b. nitrogen bases
c. hydrogen bonds
d. phosphate groups

ecotourism pay for conservation efforts.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.