Question

Fur color in dogs can be black, brown or white. The B gene is responsible for...

Fur color in dogs can be black, brown or white. The B gene is responsible for fur color. Dogs that inherit a dominant B will have black fur. Dogs that inherit 2 recessive alleles, bb, will have brown color. There is a second gene that contributes to fur color in dogs: gene I. Individuals who inherit a dominant allele, I, at this location, will always have white color. Individuals who inherit the homozygous recessive condition, ii, will be able to make coat color pigments (either brown or black).

a.) The term that best fits with how coat color in dogs is inherited is:

epistasis

multiple alleles

pleiotropy

sex-linkage

b.) If two dogs with the doubly heterozygous BbIi genotype are mated, what phenotypic ratios are expected for the offspring of this cross?

c.) Suppose dogs with the following genotypes mated: Bbii x bbIi. What proportion of the offspring from such a cross are expected to be white?

0 0
Add a comment Improve this question Transcribed image text
Answer #1

a) here the expression of genes in the B locus is determined by the genotype at the I locus if the I locus has the dominant allele then B locus is not expressed.so this is an example of dominant epistasis, If the dominant allele I is present phenotype is white regardless of the genotype at the B locus so the answer is epistasis.

( multiple alleles means a single gene has more than 2 alleles, pleiotropy means a single gene controls multiple phenotypes, Sex-linkage means the gene responsible for the phenotype is located on the X chromosome).

b) BbIi * BbIi

BI Bi bI bi
BI BBII ( white) BBIi ( white) BbII ( white) BbIi ( white)
Bi BBIi ( white) BBii (Black) BbIi ( white) Bbii (Black)
bI BbII ( white) BbIi ( white) bbII ( white) bbIi ( white)
bi BbIi ( white) Bbii (Black) bbIi ( white) bbii (brown)

expected proportion of black progeny= number of black progeny / total number of progeny=3/16

expected proportion of brown progeny= number of brown progeny / total number of progeny=1/16

expected proportion of white progeny= number of white progeny / total number of progeny=12/16

c) Bbii * bbIi

Bi bi
bI BbIi ( white) bbIi ( white)
bi Bbii (Black) bbii (brown)

proportion of white progenies= number of white progenies/total number= 2/4=1/2

Add a comment
Know the answer?
Add Answer to:
Fur color in dogs can be black, brown or white. The B gene is responsible for...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • Fur color in Labrador Retrievers is a Polygenic trait with Epistasis. There are two genes and...

    Fur color in Labrador Retrievers is a Polygenic trait with Epistasis. There are two genes and two alleles for each gene: Gene 1: Gene 2: B = Black coat (dominant) T = Add pigment to fur (Dominant) b = Brown coat (recessive) t = No pigment (Recessive) (Yellow) Mate two retrievers with these genotypes: Male BbTt x Female bbTt. From the cross above, what is the probability of having a Brown Labrador Retriever puppy?

  • with brown fur and all offspring had black fur. ne of the resulting F2 progeny were...

    with brown fur and all offspring had black fur. ne of the resulting F2 progeny were brown 7. A guinea pig with black fur was bred to one with brown fur and all offspring na When two of these F1 offspring were bred, some of the resulting F2 progeny while others were black. a. What is the dominant phenotype? How do you know?__ b. Create symbols to represent the alleles for coat color in guinea pigs. Black = Brown =...

  • In cats with tortoiseshell coat color, the fur is white with patchy black and orange spots....

    In cats with tortoiseshell coat color, the fur is white with patchy black and orange spots. In cats, the tortoiseshell gene is on the X chromosome, and the tortoiseshell phenotype requires the presence of 2 different alleles at this locus: one for orange fur (o) and one for black fur (b). What phenomenon best explains why female cats can inherit tortoiseshell coat color? In females, the alleles for coat color are pleiotropic, resulting in patches of orange and black coat...

  • In some mice, black fur (B) is dominant to white (b). At a different locus, a...

    In some mice, black fur (B) is dominant to white (b). At a different locus, a dominant allele (A) produces a band of red just below the tip of each hair. The expression of the recessive allele (a) results in solid coat color. If rabbits that are heterozygous at both loci are crossed: -what proportion of their offspring is expected to have a solid color? -what proportion of their offspring is expected to be white with a red band? -what...

  • Plesae provide a step-by-step explanation with all equations explained. This is abstract and I really want...

    Plesae provide a step-by-step explanation with all equations explained. This is abstract and I really want to understand it. In a new breed of dogs, the dominant gene B determines black coat color and bb produces brown. A separate gene E, however, shows dominant epistasis over the B and b alleles, resulting in a white coat color. The recessive e allows expression of B and b. A breeder wants to know the genotypes of her three dogs, so she breeds...

  • In mice, black fur (B) is dominant to brown fur (b). At a different locus (C)...

    In mice, black fur (B) is dominant to brown fur (b). At a different locus (C) allows the color deposition while (c) does not. Therefore, mice with cc genotype are albinos. If mice that are homozygous recessive for both characters are bred with mice who are heterozygous for both characters, what is the predicted phenotypic ratio of their offspring? PLEASE SHOW WORK, include legends and punnet squares! Thanks

  • In rabbits, spotted coat (S) is dominant to solid color (s) and black (B) is dominant...

    In rabbits, spotted coat (S) is dominant to solid color (s) and black (B) is dominant to brown (b). A true-breeding black spotted rabbit is mated to a true-breeding brown solid rabbit to Iproduce a heterozygous F1 generation. Two F1 individuals are mated. You see the four expected phenotypes of offspring, but not in the expected 9:3:3:1 (black spotted: black solid: brown spotted: brown solid) ratio. This tells you that o that the genes for fur pattern (spotted vs. non-spotted)...

  • is In guinea pigs, black coat color (B) is dominant to white (b), and rough color...

    is In guinea pigs, black coat color (B) is dominant to white (b), and rough color (R) dominant to smooth (o). What following crosses a) BBRR x bbrr b) BBrr x bbRR c) Bbrr x bbRr d) BBRr x BbRr e) BbRr x BbRr 2)The presence of one of the Rh antigens on the surface of the red blood cells (Rh+) in humans is produced by a dominant gene R. Th negative cells are produced by the recessive genotype rr....

  • In the same mouse species, a fourth unlinked gene (gene P/p) also affects fur color. For mice...

    In the same mouse species, a fourth unlinked gene (gene P/p) also affects fur color.For mice that are either homozygous dominant (PP) or heterozygous (Pp), the organism’s fur color is dictated by the other three genes (A/a, B/b, and C/c).For mice that are homozygous recessive (pp), large patches of the organism’s fur are white. This condition is called piebaldism.In a cross between two mice that are heterozygous for agouti, black, color, and piebaldism, what is the probability that offspring will...

  • 6. In tigers, a dominant allele (W) is responsible for the expression of the normal orange...

    6. In tigers, a dominant allele (W) is responsible for the expression of the normal orange pigment. Individuals that inherit twe recessive alleles (w) lack the normal orange pigment in their fur, appearing white with black stripes. A pair of normally colored parewis produces a cub that is white with black stripes and scab that is orange with black stripes. What are the possible genotypes of the cube? b. What are the possible genotypes of the parents? 6. Explain your...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT