Two subgroups of a population separated by a river are rejoined when a drought causes the river to run dry. Assuming that speciation has not yet
occurred, what is true about the two subgroups?
O A. Speciation will not occur if gene flow between the two subgroups
can increase.
B. Speciation will speed up since there will be more competition
between the subgroups.
C. New traits that resulted from mutation will not flow between the
subgroups.
D. The two subgroups will still be reproductively isolated and unable
to mate.

It's cell theory. easy name i would think.

The answer would be c, white eyes are homozygous recessive. in the early 1900s, morgan conducted several experiments with vinegar  flies (drosophila). one  sample revealed an anomaly: a  white-eyed, single male fly. he attempted to breed this fly with the typical red-eyed females. the offspring were all red-eyed. using flies from this new generation (brother-sister pairs)  produced some red-eyed and a few white-eyed flies. the white-eyed were all male. in later experiments, he was able to produce white-eyed females. this proved that white eyes are not lethal to either sex (ruling out a and b). since the percentage of white eyes to red eyes is so low, white eyes are not a dominant trait. it would be a recessive trait.