Scientists believe that there are three genes that contribute to skin color in humans. Which of these best describes the inherit
ance pattern of skin color? -multiple allele in which offspring receive three alleles from each parent -multiple allele in which offspring receive three alleles from only one parent -polygenic in which offspring receive three alleles from each parent -polygenic in which offspring receive three alleles from only one parent
Polygenic inheritance, the etymology itself, describes the trait of inheritance that is determined by more than one gene. It contradicts the Mendelian inheritance patterns which suggest that traits are determined by one gene.
The human skin color is a good example of polygenic or multiple-gene inheritance. The melanin pigment is responsible for the dark coloration of the skin and it must be noted that there are at least three genes which control the human skin color.
Utilizing a hypothetical example where the production of melanin is controlled by a so called contributing alleles (denoted as A, B, C) would result in a dark skin color and non-contributing alleles produce light skin color, it is not impossible to see a spectrum of skin colors would result in an offspring.
It must be taken into consideration that alleles do not display dominance over the other alleles. But rather, the contributing alleles does not mask the effects. It gives an additive effect- this means that each contributing allele produces one color unit.
Using two parents, heterozygous (two alleles of different types each) for each melanin-producing genes, (AaBbCc X AaBbCc), it is possible to see how additive effects and alleles combination would result to a varying types of genotypes.
Therefore, it needs an interaction between several different genes and for this to occur, it needs three alleles from both of its parents.
The answer would be, <span>-polygenic in which offspring receive three alleles from each parent.</span>
The answer to the given question above would be option B. If a topographic map included a 6,000 ft. mountain next to an area of low hills, the statement that best describe the contour lines on the map is this: <span>The contour lines around the mountain would be very close together. Hope this helps.</span>
