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Please answer and explain the following question below: 7. At least three loci a

ID: 60363 • Letter: P

Question

Please answer and explain the following question below:

7. At least three loci are known to govern coat colors in mice. The genotype C- will allow pigment to be produced at the other two loci. The recessive genotype cc does not allow pigment production, resulting in "albino" mice. The "agouti" pattern depends upon the genotype A-, and nonagouti upon the recessive aa. The color of the pigment may be black (B-) or brown (bb). Five coat colors may be produced by the action of alleles at these three loci:

a. What phenotypic frequencies are expected in the F2 from crosses of pure black with albinos of type AAbbcc? Briefly explain your answer.

b. A cinnamon male is mated to a group of albino females of identical genotype and among their progeny were observed 43 wild type, 40 cinnamon, 39 black, 41 chocolate, and 168 albino. What are the most probable genotypes of the parents?

Explanation / Answer

a. What phenotypic frequencies are expected in the F2 from crosses of pure black with albinos of type AAbbcc? Briefly explain your answer.

AaBbCc X AAbbcc

AaBbCc --- Parental, agouti black

aabbcc   --- parental, Albinos nonagouti brown

AabbCc --- crossover between genes (Bb and CC), agouti brown

aaBbcc --- crossover between genes (Bb and CC), Albinos nonagouti black

aaBbCc ---- crossover between genes (Aa and CC), nonagouti black

AabbCc ---- crossover between genes ( Aa and CC), agouti brown

aaBbCc ---- Double crossover, Nonagouti black

Aabbcc ----- Double crossover, Albinos Agouti brown

b. A cinnamon male is mated to a group of albino females of identical genotype and among their progeny were observed 43 wild type, 40 cinnamon, 39 black, 41 chocolate, and 168 albino. What are the most probable genotypes of the parents?

Most probable parent genotypes are wild type and Albinos