Question

In: Biology

In human beings, the gene for red green colorblindness (r) is sex linked and recessive to...

In human beings, the gene for red green colorblindness (r) is sex linked and recessive to its allele for normal vision (R), while the gene for freckles (F) is autosomal and dominant over its allele for nonfreckled (f). A nonfreckled, normal visioned woman whose father was freckled and colorblind, marries a freckled, colorblind man whose mother was nonfreckled.

a. What is the genotype of the woman's father? b. What is the probability that the couple's first child will be a non-freckled, normal visioned girl c. What is the probability that the first two children born to the couple will be freckled and colorblind girls? d. What is the probability that the first child born to the couple will either be a freckled, colorblind boy or a non freckled, normal visioned girl or a non-freckled, normal visioned boy e. What is the probability that the first four children born to the couple will be freckled and normal visioned girls?

Solutions

Expert Solution

colorblindness is a sex-linked recessive trait.

let the alleles be XR- normal vision, Xr- colorblindness

F-freckles, f- non-freckled.

a) woman`s father is freckled and colorblind.

the woman is non-freckled so her genotype is ff, so she has inherited f allele from both parents, so the genotype of the father is FfXrY, since the man is colorblind his genotype is XrY.

the genotype of a woman`s Father is FfXrY.

b) since the Woman`s father is the colorblind woman has inherited Xr allele from the father, so her genotype is ffXRXr.

Man is colorblind and has freckles, but his mother has no freckles so her genotype is ff, she has passed f allele to her son. he has freckles so his genotype is FfXrY.

ffXRXr * FfXrY

let`s divide this into 2 different crosses.

Ff * ff

	F	f
f	Ff	ff

probability of getting non-freckled (ff) progeny = number of ff/total number=1/2

XRXr * XrY

	XR	Xr
Xr	XRXr (normal vision female)	XrXr (colorblind female)
Y	XRY ( male, normal vision)	XrY (colorblind male)

probability of getting girl with normal vision= number of girls with normal vision/total number=1/4

probability of getting a non-freckled girl with normal vision= probability of getting non-freckled progeny probability of getting girl with normal vision=1/21/4=1/8.

probability of getting freckled child= number of Ff/total number=1/2

probability of getting colorblind female= number of colorblind female/total number=1/4

probability of getting a colorblind female child with freckles= (probability of getting freckled child probability of getting colorblind female=1/21/4=1/8.

probability of getting first two girls with colorblindness and freckles= (probability of getting a colorblind female child with freckles)^2=(1/8)^2=1/64

d) probability of getting colorblind boy= number of colorblind boys/total number=1/4

probability of getting girl with normal vision= number of girls with normal vision/total number=1/4

probability of getting normal vision boy= number of progeny with normal vision/total number=1/4

probability of getting freckled child=number of Ff/total number=1/2

probability of getting non-freckled (ff) progeny= number of ff/2=1/2

the probability that the first child born to the couple will be a freckled, colorblind boy = probability of getting colorblind boy probability of getting freckled child=1/21/4=1/8.

the probability that the first child born to the couple will be a nonfreckled, normal visioned girl = probability of getting non-freckled child probability of getting normal visioned girl= 1/21/4=1/8.

the probability that the first child born to the couple will be a non-freckled, normal visioned boy = probability of getting non-freckled child probability of getting non visioned boy= 1/21/4=1/8.

probability that the first child born to the couple will either be a freckled, colorblind boy or a non freckled, normal visioned girl or a non-freckled, normal visioned boy e = the probability that the first child born to the couple will be a nonfreckled, normal visioned girl + probability that the first child born to the couple will be a non-freckled, normal visioned boy+ the probability that the first child born to the couple will be a freckled, colorblind bo= 1/8 +1/8+1/8=3/8.

d) probability of getting freckles= ( number of ff/total number)=1/2

probability of getting a girl with normal vision= number of girls with normal vision/total number=1/4

probability of getting a freckled girl with normal vision= probability of getting non-freckled progeny probability of getting girl with normal vision=1/21/4=1/8.

probability that the first four children born to the couple will be freckled and normal visioned girls = ( probability of getting a freckled girl with normal vision)^4=(1/8)^4=1/4096

gladiator answered 4 months ago

Next > < Previous

Related Solutions

An X-linked recessive allele, r, produces red-green colorblindness in humans. A normal woman whose father was...

An X-linked recessive allele, r, produces red-green colorblindness in humans. A normal woman whose father was colorblind marries a colorblind man. a. What is the chance that the first child from this marriage will be a colorblind boy? b. What is the chance that the first child from this marriage will be a colorblind girl? c. If the couple have three children, what is the probability that two of them will be colorblind boys and one will be a normal...

a. Red green color blindness is a sex linked recessive trait. If a woman with normal...

a. Red green color blindness is a sex linked recessive trait. If a woman with normal vision whose father is colorblind marries a man with colorblindness. What would be the probability that they have a colorblind child? b. Two parents have ABO blood group genotypes. Which of the following blood types could not belong to one of their children? AB, B, O, A. c. A women who is a carrier for colorblindness marries a normal male. What is the probability...

#9 In humans red-green colorblindness is inherited in an X-linked recessive pattern. Polydactyly (extra fingers and...

#9 In humans red-green colorblindness is inherited in an X-linked recessive pattern. Polydactyly (extra fingers and toes) is inherited in an autosomal dominant pattern. A woman with polydactyly (heterozygous) and normal vision marries a man with red-green colorblindness and normal fingers and toes. What phenotypes would you expect to see among their children?

#9 In humans red-green colorblindness is inherited in an X-linked recessive pattern. Polydactyly (extra fingers and...

QUESTION 6 Red-Green colorblindness is a X-linked recessive disorder. Huntington’s is an autosomal dominant disorder. Susan’s...

QUESTION 6 Red-Green colorblindness is a X-linked recessive disorder. Huntington’s is an autosomal dominant disorder. Susan’s father is color blind and has Huntington’s disease and is heterozygous for the Huntington’s allele. Her mother is normal and has no history of colorblindness or Huntington’s in her family. Her brother has developed Huntington’s but is not colorblind. Her husband Greg is healthy and has no incidence of either disorder in his family. Susan is not colorblind and has not yet be tested...

Colorblindness is a sex linked trait in humans. Normal vision is a sex linked dominant trait....

Colorblindness is a sex linked trait in humans. Normal vision is a sex linked dominant trait. A man’s maternal grandmother had normal vision; his maternal grandfather was colorblind; his mother is colorblind; his father has normal vision. What are the genotypes of the two grandparents and parents mentioned? What type of vision does the man have himself? What type have his sisters? If he should marry a woman genotypically like one of his sisters (he is not marrying one of...

1)Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision...

1)Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents? A)XnXn and XnY B)XNXN and XNY C)XNXn and XNY D)XNXN and XnY 2)A poison interferes with the action of RNA polymerase II, but not RNA polymerase I or III. Which of the following is likely to be true of a cell exposed to the poison? A)production of tRNA would be stopped but not...

If a daughter expresses a sex-linked recessive gene, she inherited the trait from: a) her mother...

If a daughter expresses a sex-linked recessive gene, she inherited the trait from: a) her mother b) her father c) both parents d) neither parents. can you show work using the punnet square, thank you.

If a daughter expresses a sex-linked recessive gene, she inherited the trait from: a) her mother...

If a daughter expresses a sex-linked recessive gene, she inherited the trait from: a) her mother b) her father c) both parents d) neither parents. show work, thanks.

There is a “sex-linked” gene that produces a protein that allows us to properly distinguish between red...

There is a “sex-linked” gene that produces a protein that allows us to properly distinguish between red and green. There are two alleles of this gene: One allele produces the functional protein; the other allele produces a non-functional protein. In order to see normally, an individual needs only one allele that produces the functional protein (i.e. it’s not necessary to be homozygous for the functional-protein-producing-allele in order to see normally). On what chromosome is this gene found? X The allele that produces the...

Subjects