A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal...

A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was six feet tall, and both the woman's parents were of average height. Achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive. How many of their daughters might be expected to be color-blind and of normal height? Justify your answer.

Solutions

Expert Solution

Achondroplastic dwarfism is an autosomal dominant disease in which a person with homozygous dominant genotype results in lethal phenotype, heterozygous genotype results in achondroplastic dwarf and homozygous recessive genotype expresses normal height. In achondroplastic dwarfism, the development and growth of bones are interfered with by the alleles.

Colour blindness is a sex-linked recessive trait. The gene that is responsible for this disease is located on the X chromosome. It mostly affects males as compared to females. in the case of females, there are two X chromosomes whereas males have only one. So if one of the X chromosomes of a female carries an allele for colorblindness, instead of expressing the colorblind phenotype the woman becomes a carrier.

The genotype of the man who is an achondroplastic dwarf with normal vision will be DdXY

The genotype of the woman who is colorblind with normal height will be: ddXcXc

The offspring produced by these can be represented with the help of a dihybrid cross two show the independent assortment of the two unlinked genes.

Parents: DdXY (♂) × ddXc Xc (♀)

Gametes: DX, DY, dX, dY × dXc

F1 generation:

♂/♀ gametes

dXc

DdXcX

An achondroplastic dwarf daughter who is a carrier for color blindness

DdXcY

Achondroplastic dwarf son with color blindness

ddXcX

colorblind carrier daughter with normal height

ddXcY

colorblind son with normal height

Hence, we can conclude from the above cross that there will be no daughter with colorblindness though there are 50% chances for them to be of normal height or dwarf. So, a daughter with both colorblindness and normal height can not be produced by the given parents.

Answer: none

gladiator answered 1 year ago

Next > < Previous

Related Solutions

If a colorblind man marries a normal vision woman and have color blind daughter. What is...

If a colorblind man marries a normal vision woman and have color blind daughter. What is the probability that their next child will be color blind? What is the probablity that their next child will have normal vision?

A color-blind man marries a homozygous normal woman, and after several years they have two children....

A color-blind man marries a homozygous normal woman, and after several years they have two children. Unfortunately, both children have Turner syndrome, although one has normal vision and one is color-blind. The type of color blindness involved is sex-linked recessive trait. a.) Write the genotype of a person with Turner’s syndrome? b.) For the color-blind child did nondisjunction occur in the mother or the father? Explain your answer. c.) For the child with normal vision in which parent did nondisjunction...

A colorblind man marries a woman of normal vision. They have sons and daughters, all with...

A colorblind man marries a woman of normal vision. They have sons and daughters, all with normal vision and all of whom marry normal-visioned persons. Where among the grandchildren may colorblindness be expected to appear?

a) Color blindness is an X-linked trait. A female who is color blind marries a male...

a) Color blindness is an X-linked trait. A female who is color blind marries a male with no history of the condition. Show the problem. Of their children, what proportion would be expected to be color blind? Are these sons or daughters or both? Are any children carriers (having the gene, but not expressing the condition)? Are these sons or daughters or both? b)In sea horses long tail is dominant to short, and thick scales is dominant to thin. Cross...

A woman who is a carrier for the cystic fibrosis (cf) allele marries a man who...

A woman who is a carrier for the cystic fibrosis (cf) allele marries a man who is also a carrier. What percentage of the woman’s eggs will carry the cf allele?____________ What percentage of the man’s sperm will carry the cf allele?____________ The probability that they will have a child who carries 2 copies of the cf allele is equal to the percentage of eggs that carry the allele times the percentage of sperm that carry the allele. What is...

If a phenotypically normal woman whose father suffered from hemophilia marries a normal man, what is...

If a phenotypically normal woman whose father suffered from hemophilia marries a normal man, what is the probability of hemophilia occurring in the children produced by this marriage? (Show the cross and give the genetic ratios by sex.) In the next case, assume that the same woman had a husband with a genotypically homozygous normal mother but whose father also had hemophilia. What will then be the chance of hemophilia in the children? Give genotypic and phenotypic ratios for the...

A heterozygous brown-eyed human female who is color blind marries a homozygous brown-eyed male who is...

A heterozygous brown-eyed human female who is color blind marries a homozygous brown-eyed male who is not color-blind (remember, color-blindness is sex-linked). Assume that eye color is an autosomal trait and that brown is dominant over blue. a. Write out genotypes of parents and the Punnett squares for the possible offspring below first (Use the table feature to help and clearly label parental and offspring genotypes): *What is the probability that any of the offspring produced have the following traits? (please provide...

A normal man marries an affected woman with an X-linked recessive disease. The expected genotypes of...

A normal man marries an affected woman with an X-linked recessive disease. The expected genotypes of their offspring are_________.

Hemophilia is a sex-linked trait. A hemophilic man, whose father was normal, marries a woman whose...

Hemophilia is a sex-linked trait. A hemophilic man, whose father was normal, marries a woman whose father had hemophilia and whose mother was heterozygous for hemophilia. What are the chances that their son will have hemophilia? A daughter will have hemophilia? (Since there are two possibilities for the mother, you must use the data from two Punnett Squares to answer these questions.) Mr. X has been accused by Miss Z of fathering her child. The child's blood type is AB...

A woman with “hitch-hiker’s thumb” marries a man who lacks this trait (but whose mother had...

A woman with “hitch-hiker’s thumb” marries a man who lacks this trait (but whose mother had it). What is the probability that a child born to this couple will have a hitch-hiker’s thumb?

Subjects