Which of the following best describes an ecosystem?
a) all of the non-living factors that characterize in a given area
b) all of the different species living in a given area
c) all of the members of a single species living in a given area
d) all of the biotic and abiotic factors in a given area

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.