A) If they can both asexually reproduce and their offspring can also successfully asexually reproduce, then they are all the same species.
B) Examine them closely with a low-power microscope, comparing their physical characteristics to published species key lists of characteristics.
C) Base sequence the DNA of their chromosomes.
D) If they mate successfully and their offspring can also mate successfully, all are the same species.

A) different genetic strains of the same presumed fungus species
B) yeast purchased at the grocery store
C) different populations of the same bird species
D) the so-called races of humans

A) allopatric.
B) subspecies.
C) founders.
D) sympatric.