This characteristic allows organisms to blend in with their environment.
a. body chemistry
b. skin
c. camouflage
d. symmetry

C. camouflage, camouflage is when an animal is blending in with its surroundings.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".