Blonde or brown(hair)
blue or green(eyes)
short or tall
thick or skinny

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it

Amutation is basically the change in the gene, caused by alteration of single based units in the dna, or the genes or chromosomes were rearranged in the dna