Which one of the following organs secrets enzymes that affect the digestion and absorption of nutrients in the small intestine?
a. kidney
b. liver
c. pancreas
d. gallbladder

The answer is pancreas because the gall bladder stores store bile.

Reduction in overall biodiversity

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