Which of the following best describes gene flow?

I have no straight answer with ABDE as of your lack there-of. But here.

Gene flow is the introduction of genes/alleles between populations. An example is a flower having it´s pollen carried by a bee. The bee then introduces it (intentional or not.) to other flowers.

Another example is a pack of gray wolves suddenly having a different wolf introduced. *As long as it can breed, that is* They will slowly incorporate the new alleles/genes into the pack.

I wish you luck young lad.

the answer is

c. parental

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.