Group 4: Mouse coat color is controlled in part by the C gene. You know of two a
ID: 191422 • Letter: G
Question
Group 4: Mouse coat color is controlled in part by the C gene. You know of two alleles for this gene: c and c. The Callele is dominant and produces a normal, brown colored mouse coat. The calallele is recessive and produces an albino mouse. You have a mutant mouse that has a chinchilla coat pattern. You think that this is a third allele (ch) of the C gene. To test this, you performed the following crosses and recorded the outcomes. The first test cross is a chinchilla female mouse and a wildtype brown male mouse W Test Cross 1 - F Brown 57 Chinchilla 0 Albino oExplanation / Answer
Cwt = Brown = Dominant: Genotype = CwtCwt or CwtC-
Calb = Albino = Recessive: Genotype = CalbCalb
Test cross:
Chinchilla X Albino
Progeny: All brown
Assumption 1: Cch is allelic to Cwt and Calb; Cch is dominant to Calb
In such a case, the F1 should show Cch phenotype.
Assumption 2: Cch is allelic to Cwt and Calb; Cch is recessive to Calb
In such a case, the F1 should show Calb phenotype.
Assumption 3: Cch is allelic to Cwt and Calb; Cch is co-dominant to Calb
In such a case, the F1 should show Calb/Cch phenotype.
Assumption 4: Cch is not allelic to Cwt and Calb
In such a case, the F1 should show the dominant i.e, brown phenotype.
Since the progeny has only brown phenotype, it appears that Cch is not allelic to Calb or Cwt.