Crossing over occurs in prophase of meiosis i. crossing over results in a. half the number of original chromosomes. b. double the number of original chromosomes. c. genetically identical homologous chromosomes. d. new combinations of genes.

Where are the phrases

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