In cells with more than one X chromosome, one X chromosome is inactivated. The opsin1 gene is onthe X chromosome and is expressed in the retinal cells of the eye. Mutations in this gene cause therecessive trait of colorblindness. Most women who have one mutant allele of the opsin1 gene andone normal allele of the opsin1 gene (they are heterozygous) can still see color. What is the mostlikely explanation for this finding?O Any mutations in the opsin1 gene on the active X can be corrected through genetic exchange (recombination)with the inactive XO If the active X has the mutant allele of opsin1 gene, the inactive X with the normal allele will be reactivatedThe X with the mutant allele of the opsin1 gene is more likely to be inactivated because of the opsin1mutationSome retinal cells will have an active X with the mutant allele of the opsin1 gene, and some will have an activeX with the normal allele of the opsin1 gene

In individuals with two X chromosomes, a phenomenon known as X chromosome inactivation occurs,…

In cells with more than one X chromosome, one X chromosome is inactivated. The opsin1 gene is on the X chromosome and is expressed in the retinal cells of the eye. Mutations in this gene cause the recessive trait of colorblindness. Most women who have one mutant allele of the opsin1 gene and one normal allele of the opsin1 gene (they are heterozygous) can still see color. What is the most likely explanation for this finding?

In cells with more than one X chromosome, one X chromosome is inactivated. The opsin1 gene is on the X chromosome and is expressed in the retinal cells of the eye. Mutations in this gene cause the recessive trait of colorblindness. Most women who have one mutant allele of the opsin1 gene and one normal allele of the opsin1 gene (they are heterozygous) can still see color. What is the most likely explanation for this finding?

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter7: Development And Sex Determination

Section: Chapter Questions

Problem 18QP: Equalizing the Expression of X Chromosome Genes in Males and Females Males have only one X...

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Red–green color blindness is caused by an X-linked recessive genetic defect. Hence females rarely exhibit the red–green colorblind phenotype but may be carriers of the defective gene. When a narrow beam of red or green light is projected onto some areas of the retina of such a female carrier, she can readily diff erentiate the two colors, but on other areas she has diffi culty in doing so. Explain.
The gene controlling ABO blood type and the gene underlying nail-patella syndrome are said to show linkage. What does that mean in terms of their relative locations in the genome? What does it mean in terms of how the two traits are inherited with respect to each other?
Analysis of X-Linked Dominant and Recessive Traits In the eighteenth century, a young boy with a skin condition known as ichthyosis hystrix gravior was identified. The phenotype of this disorder includes thickening of skin and the formation of loose spines that are sloughed off periodically. This man married and had six sons, all of whom had the same condition. He also had several daughters, all of whom were unaffected. In all succeeding generations, the condition was passed on from father to son. What can you theorize about the location of the gene that causes ichthyosis hystrix gravior?
In 1952, an article in the British Medical Journalreported interesting differences in the behavior ofblood plasma obtained from several people who suffered from X-linked recessive hemophilia. Whenmixed together, the cell-free blood plasma from certain combinations of individuals could form clots inthe test tube. For example, the following table showswhether clots could form (+) or not (−) in variouscombinations of plasma from four people withhemophilia:1 and 1 − 2 and 3 +1 and 2 − 2 and 4 +1 and 3 + 3 and 3 −1 and 4 + 3 and 4 −2 and 2 − 4 and 4 −What do these data tell you about the inheritance ofhemophilia in these individuals? Do these data allowyou to exclude any models for the biochemical pathway governing blood clotting?
Cat fur coat color genetics is interesting. Orange fur is dominant (''B'') to black fur (''b'') and piebald, which is white spotting, is dominant (''S'') to non-white-spotted (''s''). Both of those genes are located on the X chromosome. In addition, in cats, somatic cells exhibit X-inactivation randomly, which explains why there are tortoiseshell cats (when heterozygous, have orange and black spots) as well as calico cats (orange and black but also with white spots). An orange and white spotted male is mated with a tortoiseshell female. Draw a dihybrid Punnet square to show the possible offspring:
Although most tortoiseshell cats are female, a litter of kittens will occasionally contain a male tortoiseshell. Which of the following can explain tortoiseshell coat color in a male kitten? Please explain in detail. The male kitten has an extra Y chromosome The male kitten has an extra X chromosome The male kitten has no X chromosome The male kitten cannot carry out X-inactivation
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The XG locus on the human X chromosome has twoalleles, XG+ and XG. The XG+ allele causes the presence of the Xg surface antigen on red blood cells,while the recessive XG allele does not allow antigento appear. The XG locus is 10 m.u. from the STSlocus. The STS+ allele produces normal activity ofthe enzyme steroid sulfatase, while the recessive STSallele results in the lack of steroid sulfatase activityand the disease ichthyosis (scaly skin). A man withichthyosis and no Xg antigen has a normal daughterwith Xg antigen. This daughter is expecting a child.a. If the child is a son, what is the probability he willlack Xg antigen and have ichthyosis?b. What is the probability that a son would have boththe antigen and ichthyosis?c. If the child is a son with ichthyosis, what is theprobability he will have Xg antigen?
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The gene for the production of eye colour in this species of fruit fly can be expressed aseither normal red-eyes or as brown-eyes. The allele for the normal red eyes is dominant tothat of brown, and is transmitted in normal Mendelian fashion.A gene involved with body colour in this species of fruit fly is located on the non-homologousportion of the X chromosome, and has two alleles, grey and yellow, where the grey allele isdominant to yellow.The two genes are NOT linked.a) Produce a key to clearly show the nature of the alleles associated with the eye colour inthis species of Drosophila, and in each case justify your choice of letters and / or style ofpresentation to best depict the genetics involved.