Dominant negativeIncomplete dominanceEpistasisRecessive lethal alleleIII|||EA condition where one gene has the ability tooverride the expression of another gene no matterwhat the relationship is between the other gene'salleles.A condition when a new mutation is able to suppressor revert an earlier mutation allowing wildtypefunction to reappear.A condition where a recessive allele influences theshape of a protein dimer product in theheterozygous condition so that it neither resemblesthe homozygous dominant nor the homozygousrecessive conditions leading to a LOF in theheterozygous state and the recessive state.A condition where two recessive alleles will be fatalto an offspring although it will not affect a Incomplete dominanceEpistasisRecessive lethal alleleRevertant||||A condition when a new mutation is able to suppressor revert an earlier mutation allowing wildtypefunction to reappear.A condition where a recessive allele influences theshape of a protein dimer product in theheterozygous condition so that it neither resemblesthe homozygous dominant nor the homozygousrecessive conditions leading to a LOF in theheterozygous state and the recessive state.A condition where two recessive alleles will be fatalto an offspring although it will not affect aheterozygous condition.A condition where neither the dominant allele northe recessive allele would be fully expressed.

Introduction : The field of science known as genetics deals with the study of heredity, genetic…

Dominant negative Incomplete dominance Epistasis Recessive lethal allele III E ||| A condition where one gene has the ability to override the expression of another gene no matter what the relationship is between the other gene's alleles. A condition when a new mutation is able to suppress or revert an earlier mutation allowing wildtype function to reappear. A condition where a recessive allele influences the shape of a protein dimer product in the heterozygous condition so that it neither resembles the homozygous dominant nor the homozygous recessive conditions leading to a LOF in the heterozygous state and the recessive state. A condition where two recessive alleles will be fatal to an offspring although it will not affect a

Dominant negative Incomplete dominance Epistasis Recessive lethal allele III E ||| A condition where one gene has the ability to override the expression of another gene no matter what the relationship is between the other gene's alleles. A condition when a new mutation is able to suppress or revert an earlier mutation allowing wildtype function to reappear. A condition where a recessive allele influences the shape of a protein dimer product in the heterozygous condition so that it neither resembles the homozygous dominant nor the homozygous recessive conditions leading to a LOF in the heterozygous state and the recessive state. A condition where two recessive alleles will be fatal to an offspring although it will not affect a

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter11: Genome Alterations: Mutation And Epigenetics

Section: Chapter Questions

Problem 16QP: Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior...

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In retinoblastoma, a mutation in one allele of the RB1 tumorsuppressorgene can be inherited from the germ line, causingan autosomal dominant predisposition to the developmentof eye tumors. To develop tumors, a somatic mutation in thesecond copy of the RB1 gene is necessary, indicating that themutation itself acts as a recessive trait. Given that the firstmutation can be inherited, in what ways can a second mutationalevent occur?
Ehler-Danlos syndrome is a rare disorder caused by a mutation ina gene that encodes a protein called collagen (type 3 A1). Collagenis found in the extracellular matrix that plays an important role inthe formation of skin, joints, and other connective tissues. Peoplewith Ehler-Danlos syndrome have extraordinarily flexible skin andvery loose joints. The following pedigree contains several individualsaffected with this syndrome, shown with black symbols. Basedon this pedigree, does the syndrome follow autosomal recessive,autosomal dominant, X-linked recessive, or X-linked dominantinheritance? Explain your reasoning.
Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior history of the disease. Consider the following pedigree (the darkly colored symbols represent affected individuals): a. Circle the individual(s) in which the mutation most likely occurred. b. Is the person who is the source of the mutation affected by retinoblastoma? Justify your answer. c. Assuming that the mutant allele is fully penetrant, what is the chance that an affected individual will have an affected child?
. The production of pigment in the outer layer of seedsof corn requires each of the three independently assorting genes A, C, and R to be represented by at leastone dominant allele, as specified in Problem 64. Thedominant allele Pr of a fourth independently assortinggene is required to convert the biochemical precursorinto a purple pigment, and its recessive allele pr makesthe pigment red. Plants that do not produce pigmenthave yellow seeds. Consider a cross of a strain of genotype A/A ; C/C ; R/R ; pr/pr with a strain of genotypea/a ; c/c ; r/r ; Pr/Pr.a. What are the phenotypes of the parents?b. What will be the phenotype of the F1?c. What phenotypes, and in what proportions, willappear in the progeny of a selfed F1?d. What progeny proportions do you predict from thetestcross of an F1?
In individuals affected by cystic fibrosis, salt crystals may appear afterperspiration dries up. In addition, the disease causes respiratory disorderswhich can be both debilitating and lethal. It occurs in individuals homozygousfor the recessive gene. Two normal parents had a daughter with thesymptoms of this disease, and a normal son who marries a normal womanwith an afflicted A test (salt concentration in perspiration of heterozygotes ishigher than normal) disclosed that both are indeed carriers of the gene. If thefirst child born to the mating in (b) was defective, what is the probability thatthe 2nd child would also be defective?Express answer in fraction form
. A diploid strain of yeast was made by mating a haploidstrain with a genotype w−, x−, y−, and z− with a haploidstrain of opposite mating type that is wild type for thesefour genes. The diploid strain was phenotypically wildtype. Four different X-ray-induced diploid mutantswith the following phenotypes were produced fromthis diploid yeast strain. Assume a single new mutation is present in each strain.Strain 1 w− x+ y− z+Strain 2 w+ x− y− z−Strain 3 w− x+ y− z−Strain 4 w− x+ y+ z+When these mutant diploid strains of yeast go throughmeiosis, each ascus is found to contain only two viablehaploid spores.a. What kind of mutations were induced by X-rays tomake the listed diploid strains?b. Why did two spores in each ascus die?c. Are any of the genes w, x, y, or z located on thesame chromosome?d. Give the order of the genes that are found on thesame chromosome
Null mutations are valuable genetic resources becausethey allow a researcher to determine what happens to anorganism in the complete absence of a particular protein. However, it is often not a trivial matter to determinewhether a mutation represents the null state of the gene.a. Geneticists sometimes use the following test forthe nullness of an allele in a diploid organism: If theabnormal phenotype seen in a homozygote for theallele is identical to that seen in a heterozygote(where one chromosome carries the allele in question and the homologous chromosome is known tobe completely deleted for the gene) then the alleleis null. What is the underlying rationale for thistest? What limitations might there be in interpreting such a result?b. Can you think of other methods to determinewhether an allele represents the null state of a particular gene?
Ehler-Danlos syndrome is a rare disorder caused by a mutation ina gene that encodes a protein called collagen (type 3 A1). Collagenis found in the extracellular matrix that plays an important role inthe formation of skin, joints, and other connective tissues. Peoplewith Ehler-Danlos syndrome have extraordinarily flexible skin and very loose joints. The pedigree below contains several individualsaffected with this syndrome, shown with black symbols. Based onthis pedigree, does the syndrome appear to follow autosomalrecessive, autosomal dominant, X-linked recessive, or X-linkeddominant inheritance? Explain your reasoning.
The maternal-effect mutation bicoid (bcd) is recessive. Inthe absence of the bicoid protein product, embryogenesis isnot completed. Consider a cross between a female heterozygousfor the bicoid mutation (bcd+/ bcd-) and a homozygousmale(bcd-/ bcd-). How is it possible for a male homozygous for the mutationto exist?
Sickle-cell anemia is a recessive autosomal disorderthat is caused by an amino acid substitution in theβ-hemoglobin protein. The DNA mutation underlyingthis substitution is a SNP that alters a GAG codon forthe amino acid glutamate to a GTG that codes a valine.The frequency of sickle-cell anemia among AfricanAmericans is about 1/400. What is the frequency ofthis GTG codon in the β-hemoglobin gene amongAfrican Americans?
A boy with Klinefelter syndrome (47,XXY) is born to a motherwho is phenotypically normal and a father who has the X-linkedskin condition called anhidrotic ectodermal dysplasia. The mother’sskin is completely normal with no signs of the skin abnormality.In contrast, her son has patches of normal skin and patchesof abnormal skin. Question: Using the appropriate genetic terminology, describe themeiotic mistake that occurred. Be sure to indicate in whichdivision the mistake occurred.
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?