Cats have an Xlinked orange gene O and o alleles that is imp

Cats have an X-linked orange gene (O and o alleles) that is important for the coloration of fur pigment. A pair of recessive alleles will give black fur.

A) Using your knowledge of genetic nomenclature what would be the genotype of a male black cat? Explain your reasoning.

B) Using your knowledge of genetics what would be the most likely genotype of an orange female cat? Explain your reasoning.

C) Describe both the phenotype and genotype of the different progeny classes you would expect to see from a cross between a black male cat with an orange female cat (based on the genotypes you describe above).

D) Describe both the phenotype and genotype of the different progeny classes you would expect to see from the reciprocal cross of the one performed in part c of this question?

Thank you.

Solution

Answer:

A). balck male cat genotype = X^o Y

X^O = Organge

X^o = black

Male cats have only one X chromosome

B). Organge female genotype= X^O X^O or X^O X^o

Female cats consist of two X chromosomes and the allele of organge color is dominant. So, both homozygous and heterozygous conditions show organge color.

C).

black male cat X an orange female cat

X^o Y     x    X^O X^O (homozygous)

X^O

X^o

X^O X^o (orange female)

Y

X^O Y (Orange male)

All progeny are orgnae phenotypically.

Genotypically, Organge female : Orange male = 1:1

D).

X^o X^o (balck female)    x    X^O Y (orange male)

X^O

Y

X^o

X^O X^o (orange female)

X^oY(black male)

Phenotypically:

Orange : black = 1:1

Genotypic ratio = X^O X^o : X^oY = 1 :1