In pea plants, the tall-stem allele and the short-stem allele are different forms of the same what'

the answer to your question is definitely genes

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

Yes yes yes very good