How Many Of These 64 Possible Offspring Have Skin That Is Darker Than Their Parents? Answers

The Genetics and Evolution of Pare Color: The Case of Desiree's Baby
Developed past Patricia Schneider. Copyright 2003 National Center for Example Study Teaching in Science . Used with permission.

HANDOUT #two
Skin Color is a Polygenetic (Multiple Gene) Trait

Differences in skin colour are largely due to differences in the amount of melanin, a nighttime paint, produced past pare cells. At least 3 genes command the synthesis of melanin. Each factor has two forms: an allele for loftier melanin product or dark skin (A,B,C) and an allele for low melanin production or light pare (a,b,c). Each nighttime skin allele (A,B,C) in the genotype adds a small but equal amount of pigment to the peel. At that place are seven different shades of skin color ranging from very night (AABBCC) to very lite (aabbcc). Most individuals produce a medium corporeality of melanin and are of intermediate skin color (AaBbCc).

The following Punnett foursquare shows the possible offspring from a cross between two individuals of intermediate skin color.

AaBbCc X AaBbCc
(each square shows the number of dark skin alleles in the genotype)

Gametes	ABC	ABc	AbC	Abc	aBC	aBc	abC	abc
ABC	half-dozen AABBCC	5 AABBCc	5 AABbCC	four AABbCc	v AaBBCC	4 AaBBCc	four AaBbCC	3 AaBbCc
ABc	5 AABBCc	4 AABBcc	iv AABbCc	3 AABbcc	4 AaBBCc	3 AaBBcc	3 AaBbCc	ii AaBbcc
AbC	5 AABbCC	4 AABbCc	4 AAbbCC	3 AAbbCc	4 AaBbCC	3 AaBbCc	3 AabbCC	2 AabbCc
Abc	4 AABbCc	3 AABbcc	3 AAbbCc	ii AAbbcc	3 AaBbCc	2 AaBbcc	2 AabbCc	ane Aabbcc
aBC	v AaBBCC	four AaBBCc	4 AaBbCC	3 AaBbCc	4 aaBBCC	3 aaBBCc	3 aaBbCC	2 aaBbCc
aBc	four AaBBCc	3 AaBBcc	3 AaBbCc	ii AaBbcc	3 aaBBCc	2 aaBBcc	2 aaBbCc	i aaBbcc
abC	4 AaBbCC	three AaBbCc	three AabbCC	2 AabbCc	three aaBbCC	2 aaBbCc	2 aabbCC	1 aabbCc
abc	iii AaBbCc	2 AaBbcc	2 AabbCc	1 Aabbcc	2 aaBbCc	i aaBbcc	1 aabbCc	0 aabbcc

The offspring of this cross exhibit seven shades of pare colour based on the number of dark skin alleles in each genotype.

Questions

Each parent produces eight unlike types of gametes, which tin combine in 64 different means. Complete the following tabular array:
How many of these 64 possible offspring have skin that is darker than their parents?
Each of these 3 genes has two alleles. Are the night skin alleles dominant to the light peel alleles?
There are more than 7 shades of skin color. Tin can you offer an explanation?
Utilise this model of skin color inheritance and the information provided in the short story to develop possible genotypes for each of the following characters: Monsieur and Madame Aubigny, Armand Aubigny, Desiree'south mother and father, Desiree, and Desiree'southward infant.

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Source: https://www.pbs.org/race/000_About/002_04-teachers-06b.htm

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