Gene flow or migration is the transfer of alleles or genes from one population to another. select the combination of facts that indicate the occurrence of gene flow in the fugate family. i. four of the fugate's seven children had blue complexions. ii. travel in and out of this area was rare in the 1800's, but is more common now. iii. according to doctors, occurrence of the condition is rarely seen anymore. iv. methemoglobinemia at 10-20 percent of hemoglobin can cause blue skin without more serious symptoms. a)i. and iv. b)i. and iii. c)iii. and iv. d)ii. and iii.

The correct answer to this question is B. Some members of the Fugate family had a genetic condition called methemoglobinemia, that gave a blue color to their skin. The gene causing this disease is an autosomal recessive gene, so to have this condition you need to be homozygotes for this recessive gene. Gene flow was prevalent in the Fugate family since not all of the children had blue complexion, but only four of them. The three children that did not have blue complexion, had the dominant allele, probably through gene migration from another population nearby. Also, since it is easier nowadays to travel, two separate populations could meet more easily. This increases the incidence of gene flow and explains the reduction of the occurrence of the condition.

Option B , I. and III.

Explanation:

From statement I and III, it is clear that four children out of seven children suffer from blue skin complexion which is not something very common to occur in a family without any hereditary background. Also the doctors claimed that blue skin issue is rarely seen these days. Thus, there are high chances of acquiring this problem from ancestors (affected or non-affected (carriers))

Therefore, both options I and III depict that some where the origin of blue skin disorder is associated with hereditary of the family.  

Hence, option B is correct