Consider a man the genotype Bb who leaves his country of birth and moves to another country where all of the people have the genotype BB.
He marries a BB woman and they have a Bb child. Is this an example of gene flow or genetic drift?
a- gene flow
c-neither of the above
Gene flow is when you have the situation you described in your scenario, where you have a different set of genes introduced into a population because of migration or moving from one place to another. Genetic drift, on the other hand, is a change in the gene frequency due to random sampling. Maybe you got the wrong people if you are doing a random sample and the frequency of the genes you are looking for don't meet expectations, either increasing or decreasing. Gene flow is very important in promoting biodiversity. The interbreeding of different genes can have positive results. Vitually all the dog breeds known to man are the result of selective breeding efforts, specifically to cultivate a set of desired characteristics in a particular breed of dog. You should pick letter "a", the correct answer for this question is "gene flow".