3. Discuss the evolutionary relationships among the four classes of sponges.

Organism, organ system, organs, tissue, cells

No they’ve not done that

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