Final answer:
Geographical isolation is the term used to describe reproductive isolation when organisms live in separate geographical areas and cannot mate due to physical separation.
Step-by-step explanation:
When organisms live in separate geographical areas and mating is not possible due to this physical separation, the term used to describe this type of reproductive isolation is geographical isolation. This form of isolation is an aspect of allopatric speciation, where groups from the same species become reproductively isolated due to geographical barriers, such as mountains, rivers, or distances. Over time, these isolated populations may evolve into distinct species due to the lack of gene flow between them. Geographical isolation is different from temporal isolation, which is reproductive isolation due to differences in breeding times, and behavioral isolation, which is due to differences in mating behaviors that prevent interbreeding.