Question

coat color in mice depends on three alleles. coat color alelle inheritance pattern agouti c dominant to other alleles black c^{\text{b}} b start superscript, start text, b, end text, end superscript dominant to albino albino c recessive a scientist crosses a black mouse (c^{\text{b}} b start superscript, start text, b, end text, end superscriptc) with an agouti mouse (cc^{\text{b}} b start superscript, start text, b, end text, end superscript). what are the predicted phenotypes of their offspring?

Answer 1

The predicted phenotypes of the offspring would be 9 agouti, 3 black, and 4 albino.

Step-by-step explanation:

The predicted phenotypes of the offspring from a cross between a black mouse (CbC) and an agouti mouse (Ccb) would be 9 agouti, 3 black, and 4 albino. The agouti coat color (A) is dominant to black, and black is dominant to albino. The presence of the recessive c allele at the pigment production gene (C) causes the mice to be albino, regardless of the allele at the coat color gene (A).

Answer 2

The correct option is d.

The offspring from the cross between a black mouse (cᴇc) and an agouti mouse (C_c b) are predicted to have a 1:1 phenotypic ratio, where 50% will be agouti and 50% will be black, with no albino offspring produced.

The question is asking about the phenotypes of the offspring from a cross between a black mouse with genotype cᴇc and an agouti mouse with genotype C_c b.

Given the dominance hierarchy, agouti (C) is dominant to black (cb) and both are dominant to albino (c), with the gene responsible for pigment production (C) being epistatic to the gene responsible for coat color (A).

Therefore, any presence of the recessive 'c' allele in the homozygous form (cc) will result in an albino phenotype, irrespective of the 'A' gene's alleles.

In this genetic cross, the possible offspring's genotypes are: C_c b and cᴇc b. The black mouse can only pass on a cb allele, and the agouti mouse can pass on either a C or cb allele.

Since the C allele is dominant to cb, all offspring that receive a C allele will be agouti. If they receive two cb alleles, they will be black. Since none of the parents carry a cc genotype, albino offspring are not possible.

The predicted phenotypic ratio of the offspring is therefore 1 agouti (C_c b): 1 black (cᴇc b). Answering the multiple-choice question, the correct option would be D. 50% of the offspring will have agouti coats, and 50% will have black coats.

The complete question is here:

coat color in mice depends on three alleles.

Column A Coat Colour

Agouti

Black

Albino

Column B Allele

C

cb

c

Column C Inheritance Pattern

dominant to other alleles

dominant to albino

recessive

A scientist crosses a black mouse (cᵇc) with an agouti mouse (C_c b)

What are the predicted phenotypes of their offspring?

A. 25% of the offspring will have agouti coats, 50% will have black coats, and 25% will have albino coats.

B. 25% of the offspring will have agouti coats, and 75% will have black coats.

C. 50% of the offspring will have agouti coats, 25% will have black coats, and 25% will have albino coats.

D. 50% of the offspring will have agouti coats, and 50% will have black coats.