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?
Q: In Drosophila, the autosomal recessive brown eyecolor mutation displays interactions with both…
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A: Hello! Since you have posted multiple questions, we are answering only first two questions. If you…
Q: Genes that cause Prader-Willi syndrome and Angelman syndromeare closely linked along chromosome 15.…
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Q: A. What are the genotypes of the following: Jane: ______________________ James:…
A: Given G6PDD (g) = X-linked recessive condition. Fragile X syndrome (F) = X-linked dominant…
Q: A 30 - year - old woman was undergoing therapy for b-thalassemia,a recessive trait caused by absence…
A: Bone marrow or HSC (hematopoietic stem cells) transplantation is a procedure during which healthy…
Q: Ehler-Danlos syndrome is a rare disorder caused by a mutation ina gene that encodes a protein called…
A: The Ehler-Danlossyndrome is a disorder caused by a mutation in the gene codes for the protein…
Q: Sex-linked inheritance
A: Introduction : Glucose-6-phosphate dehydrogenase deficiency/G6PDD (g) is an X-linked recessive…
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A: There are two types of sex chromosomes X and Y chromosomes. The autosomes are the same in both male…
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A: Firstly, let's assume that we have isolated the normal gene from a healthy human, say gene X…
Q: A DNA variant has been found linked to a rare autosomal dominant disease in humans and can thus…
A: A variant of DNA (deoxyribose nucleic acid) is linked to a rare type of dominant, autosomal disease…
Q: The accompanying pedigree shows the pattern of transmission of two rare human phenotypes: cataract…
A: Inheritance is the process of transmitting the traits from parent to offspring. Traits of an…
Q: . Human geneticists interested in the effects of abnormalities in chromosome number often…
A: The abnormal number chromosomes in the cell is called as aneuploidy. For example, instead of 46…
Q: On rare occasions, people are born with a condition known as uniparental disomy. It happens when an…
A: Human contains two number of chromosomes 15, one inherited from mother (maternal) and one from…
Q: . Researchers discovered recently that the sole functionof the SRY protein is to activate an…
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Q: In humans, discoloration of the teeth is controlled by the dentine sialophosphoprotein (DSPP) gene…
A: The normal colour of teeth is white hue color, a slightly yellowish layer for protection.
Q: The pedigree here shows the inheritance of a human disease knownas familial hypercholesterolemia.…
A: Pedigree analysis can be described as the record of a special genetical character or a disorder for…
Q: Six months pregnant, an expectant mother had a routineultrasound that showed that the limbs of the…
A: In genetics, achondroplasia is defined as the rare type of genetic disorder related to the growth of…
Q: A female patient 19 years old, whose symptoms areanemia and internal bleeding due to a massive…
A: Hello. Since your question has multiple sub-parts, we will solve first three sub-parts for you. If…
Q: Pancreatic cancer is clearly inherited as an autosomal dominant trait in the family illustrated in…
A: Cancer is an uncontrolled division of cell that has a defunct apoptosis mechanism. Usually, when…
Q: The accompanying pedigree is for a rare, but relativelymild, hereditary disorder of the skin.a. How…
A: The mating id done beween the genotypes Dd and dd. Hence, we conclude from this that the probablity…
Q: In individuals affected by cystic fibrosis, salt crystals may appear after perspiration dries up. In…
A: Cystic fibrosis is an autosomal recessive disorder. Cystic fibrosis is a inherited disease that…
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A: Answer : Since 2 cases were the ones which already had the mutation already present in their…
Q: What characteristics of the pedigree suggest that pancreatic cancer in this family is inherited as…
A: Introduction Pedigree Analysis: This is the new approach to study the inheritance pattern in the…
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Q: 2. Uniparental disomy is a rare phenomenon in whichonly one of the parents of a child with a…
A: Uniparental disomy (UPD) occurs when a person receives two copies of a chromosome, or part of a…
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Q: The maternal-effect mutation bicoid (bcd) is recessive. Inthe absence of the bicoid protein product,…
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Q: Consider two hypothetical recessive autosomal genesa and b, where a heterozygote is testcrossed to a…
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Q: . The human IGF2 gene is autosomal and maternallyimprinted. Copies of the gene received from…
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Q: In Drosophila, a cross (cross 1) was made between twomutant flies, one homozygous for the recessive…
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Q: In humans, discoloration of the teeth is controlled by the dentine sialophosphoprotein (DSPP) gene…
A: DSPP gene that is responsible for discoloration of the teeth is present on chromosome number 4. I…
Q: Null mutations are valuable genetic resources becausethey allow a researcher to determine what…
A: Null mutation is a type of mutation in which a copy of gene becomes non-functional. This type of…
Q: Olivia S. was born with a rare recessive disorder called tyrosinemia.The next day, Olivia M. was…
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Q: The maternal-effect mutation bicoid (bcd) is recessive. Inthe absence of the bicoid protein product,…
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Q: Among mammals, measurements of the rate of generation of autosomal recessive mutations have been…
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Q: Albinism occurs when cells cannot chemically synthesize pigment molecules. This occurs because the…
A: Albinism is a category of genetic illnesses in which the pigment melanin, which affects the colour…
Q: In humans, discoloration of the teeth is controlled by the dentine sialophosphoprotein (DSPP) gene…
A: The normal colour of teeth is white hue color, a very slight yellowish layer for protection.
Q: A 30 - year - old woman was undergoing therapy for b-thalassemia,a recessive trait caused by absence…
A: Introduction: Beta thalassemia is an autosomal recessive inherited from abnormal genes of parent. In…
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A: When mice carry Avy allele, it exhibits the darker coat. This phenotype is thought to be caused by…
Q: In the nematode C. elegans, some worms have blisteredcuticles due to a recessive mutation in one of…
A: Suppressor mutations are defined as the mutations that take place only if there is the presence of…
Q: How can the retinoblastoma trait be inherited in a dominant fashion if the deletion of the RB gene…
A: Retinoblastoma is an eye cancer that begins in the retina.
In retinoblastoma, a mutation in one allele of the RB1 tumorsuppressor
gene can be inherited from the germ line, causing
an autosomal dominant predisposition to the development
of eye tumors. To develop tumors, a somatic mutation in the
second copy of the RB1 gene is necessary, indicating that the
mutation itself acts as a recessive trait. Given that the first
mutation can be inherited, in what ways can a second mutational
event occur?
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- A female patient 19 years old, whose symptoms areanemia and internal bleeding due to a massive buildupof leukemic white blood cells, is diagnosed withchronic myelogenous leukemia (CML). Karyotypeanalysis shows that the leukemic cells of this patientare heterozygous for a reciprocal translocation involving chromosomes 9 and 22. However, none of thenormal, nonleukemic cells of this patient contain thetranslocation. Which of the following statements istrue and which is false?a. The translocation results in the inactivation (loss offunction) of a tumor-suppressor gene.b. The translocation results in the inactivation (loss offunction) of an oncogene.c. There is a 50% chance that any child of this patientwill have CML.d. This patient is a somatic mosaic in terms of thekaryotype.e. DNA extracted from leukemic cells of this patient,if taken up by normal mouse tissue culture cells,could potentially transform the mouse cells intocells capable of causing tumors.f. The normal function of the…What characteristics of the pedigree shown in Figure 23.1 suggest thatpancreatic cancer in this family is inherited as an autosomal dominanttrait?Cornelia de Lange syndrome (CdLS) is a rare humandisease caused by a dominant loss-of-function mutation in any one of at least five different genes, all ofwhich encode components or regulators of the cohesin protein complex. People with CdLS have a widerange of morphological abnormalities, growth retardation, and mental impairment. Analysis of CdLS patients shows that in addition to chromosomalmis-segregation during cell division, their abnormalphenotype is likely due to widespread mis-regulationof gene expression during development. Cohesin mayplay a role in organizing chromatin loops necessaryfor proper regulation of transcription. (You will learnmore about this topic in Chapter 17.)a. In different families, CdLS can show an autosomaldominant or X-linked dominant inheritance pattern. How is this possible?b. Explain how a loss-of-function allele in a gene encoding a cohesin protein could be dominant to itswild-type counterpart.c. CdLS is usually caused by new mutation in oneparent’s…
- Six months pregnant, an expectant mother had a routineultrasound that showed that the limbs of the fetus wereunusually short. Her physician suspected that the babymight have a genetic form of dwarfism called achondroplasia,an autosomal dominant trait occurring with a frequency of about1 in 27,000 births. The parents were directed to a genetic counselorto discuss this diagnosis. In the conference, they learnedthat achondroplasia is caused by a mutant allele. Sometimes itis passed from one generation to another, but in 80 percent ofall cases it is the result of a spontaneous mutation that arisesin a gamete of one of the parents. They also learned that mostchildren with achondroplasia have normal intelligence and a normallife span. It has been suggested that prenatal genetic testing for achondroplasiabe made available and offered to all women. Wouldyou agree with this initiative? What ethical considerationswould you consider when evaluating the medical and societalconsequences of offering…Six months pregnant, an expectant mother had a routineultrasound that showed that the limbs of the fetus wereunusually short. Her physician suspected that the babymight have a genetic form of dwarfism called achondroplasia,an autosomal dominant trait occurring with a frequency of about1 in 27,000 births. The parents were directed to a genetic counselorto discuss this diagnosis. In the conference, they learnedthat achondroplasia is caused by a mutant allele. Sometimes itis passed from one generation to another, but in 80 percent ofall cases it is the result of a spontaneous mutation that arisesin a gamete of one of the parents. They also learned that mostchildren with achondroplasia have normal intelligence and a normallife span. What information would be most relevant to concluding whichof the two mutation origins, inherited or new, most likelypertains in this case? How does this conclusion impact on thiscouple’s decision to have more children?Pancreatic cancer is clearly inherited as an autosomal dominant trait in the family illustrated in Figure 23.1. Yet most cases of pancreatic cancer are sporadic, appearing as isolated cases in families with no obvious inheritance. How can a trait be strongly inherited in one family and not inherited in another?
- Glucose-6-phosphate dehydrogenase deficiency/G6PDD (g) is an X-linked recessive conditionwherein the red blood cells of affected individuals undergo premature hemolysis. Fragile X syndrome(F), on the other hand, is an X-linked dominant mutation characterized by a mild to moderateintellectual disability. Amelogenesis imperfecta (A) is a congenital disorder affecting the formation ofthe teeth enamel making affected individuals at higher risk for dental cavities and related problems.Only male offspring inherit this condition. Jane is heterozygous for both X-linked traits like her mother. Her father is normal for both X-linked traits. James has a mother who suffers from G6PDD but not from fragile X-syndrome. His fatherdoes not exhibit any X-linked disorder but has amelogenesis imperfecta. A. What are the genotypes of the following: Jane: ______________________ James: ______________________Jane’s mother: _________________ James’ mother: ________________Jane’s father: __________________…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.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
- 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.Diamond–Blackfan anemia (DBA) is a rare, dominantgenetic disorder characterized by bone marrow malfunction,birth defects, and a predisposition to certaincancers. Infants with DBA usually develop anemia in the firstyear of life, have lower than normal production of red blood cellsin their bone marrow, and have a high risk of developing leukemiaand bone cancer. At the molecular level, DBA is causedby mutations in any one of 10 genes that encode ribosomalproteins. The first-line therapy for DBA is steroid treatment,but more than half of affected children develop resistance tothe drugs and in these cases, treatment is halted. DBA can betreated successfully with bone marrow or stem cell transplantsfrom donors with closely matching immune system markers.Transplants from unrelated donors have significant levels ofcomplications and mortality. Given that a faulty ribosomal protein is the culprit and causesDBA, discuss the possible role of normal ribosomal proteins.Why might bone marrow cells be…Diamond–Blackfan anemia (DBA) is a rare, dominantgenetic disorder characterized by bone marrow malfunction,birth defects, and a predisposition to certaincancers. Infants with DBA usually develop anemia in the firstyear of life, have lower than normal production of red blood cellsin their bone marrow, and have a high risk of developing leukemiaand bone cancer. At the molecular level, DBA is causedby mutations in any one of 10 genes that encode ribosomalproteins. The first-line therapy for DBA is steroid treatment,but more than half of affected children develop resistance tothe drugs and in these cases, treatment is halted. DBA can betreated successfully with bone marrow or stem cell transplantsfrom donors with closely matching immune system markers.Transplants from unrelated donors have significant levels ofcomplications and mortality. While a stem cell transplant from an unaffected donor is currentlythe only cure for DBA, genome-editing technologies mayone day enable the correction of…