Question

Pigment in mouse fur is only produced when the C allele is present- Individuals of the cc genotype are white- If color ispresent, it may be determined by the A, a alleles. AA or Aa results in agouti color, while aa results in black coats.(a) What F1 and F2 genotypic and phenotypic ratios are obtained from a cross between AACC and aacc mice?(b) In three crosses between agouti females whose genotypes were unknown and males of the aacc genotype, thefollowing phenotypic ratios were obtained:(1) 8 agouti(2} 9 agouti(3) 4 agouti10 black 5 blackWhat are the genotypes of these female parents?

Answer 1

Answer:

(a).From the dihybridized cross between the AACC genotypes with aacc in the first filial generation, 100% of the AaCc genotype representing the genotype of mice with pigment is obtained (f1) because the C allele dominates and Aa results in an agouti color. For the second generation where a cross is made between the genotypes resulting from the F1 AaCc generation. Obtaining the following proportions of phenotypes 9 (agouti with pigment): 3 (white agouti): 3 (black coats with pigment): 1 (black coats and white).

(b). 1.  Genotype of the female: AaCC

2.Genotype of the female:AACC

3.Genotype of the female: aaCC