An additional gene, called W, is found that affects the synthesis of enzymes 1 and 2. Mutantd has a recessive mutation in gene W.genotypeenzyme activitywithout fictaminewith fictamine1strainWXY122wild-type +++++mutant a+mutant b+mutant c+++mutant d++++Once again, justify each answer in one sentence.i) Is gene W most likely a positive or a negative regulator?ii) Is the activity of W activated or inactivated by the presence of fictamine?++++Z++++++++H++++!1++

Introduction Positive regulator is a substance which increases the rate of enzymes activity.…

An additional gene, called W, is found that affects the synthesis of enzymes 1 and 2. Mutant d has a recessive mutation in gene W. genotype enzyme activity without fictamine with fictamine strain W Y Z 1 2 wild-type + + + mutant a + + mutant b + + mutant c + mutant d + ++ ++ Once again, justify each answer in one sentence. i) Is gene W most likely a positive or a negative regulator? ii) Is the activity of W activated or inactivated by the presence of fictamine? + + + + + + + ++ ¦ : ++ ++ -- ++ ++ ! ! ! ! : : ++

An additional gene, called W, is found that affects the synthesis of enzymes 1 and 2. Mutant d has a recessive mutation in gene W. genotype enzyme activity without fictamine with fictamine strain W Y Z 1 2 wild-type + + + mutant a + + mutant b + + mutant c + mutant d + ++ ++ Once again, justify each answer in one sentence. i) Is gene W most likely a positive or a negative regulator? ii) Is the activity of W activated or inactivated by the presence of fictamine? + + + + + + + ++ ¦ : ++ ++ -- ++ ++ ! ! ! ! : : ++

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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Prader-Willi syndrome is caused by a mutation in anautosomal maternally imprinted gene. Label the following statements as true or false, assuming that thetrait is 100% penetrant.a. Sons of affected males have a 50% chance of showing the syndrome.b. Daughters of affected males have a 50% chance ofshowing the syndrome.
Figure 1-15 shows the family tree, or pedigree, for LouiseBenge (Individual VI-1) who suffers from the diseaseACDC because she has two mutant copies of the CD73gene. She has four siblings (VI-2, VI-3, VI-4, and VI-5)who have this disease for the same reason. Do all of the10 children of Louise and her siblings have the samenumber of mutant copies of the CD73 gene, or mightthis number be different for some of the 10 children?
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?
In McCune-Albright syndrome, fibrous connective tissue replaces bone, tan patches (café-au-lait spots) dot the skin, and hormone abnormalities cause early puberty and malfunction of the thyroid, pituitary, and adrenal glands. The phenotype is highly variable, and all patients are somatic mosaics for the mutation, which is in the gene GNAS1. Why is the condition seen only in mosaics?
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?
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…
You learned in Problem 21 in Chapter 7 that theneurodegenerative disease ALS can be caused by expansion of a hexanucleotide repeat region (5′-GGGGCC-3′)outside of the open reading frame (but within the firstintron) of the gene called C9ORF72. While a normalC9ORF72 allele has 2–23 copies of the hexanucleotiderepeat unit, dominant disease-causing alleles have hundreds or even thousands of copies. Researchers observed that the first intron of theC9ORF72 disease allele is transcribed not only fromthe normal template strand of DNA, but also from thenontemplate strand. Even more unusual, both types ofrepeat-region transcripts are translated in all six readingframes in an AUG-independent manner—a processcalled repeat-associated non-ATG translation, or RANtranslation. These discoveries led to the hypothesisthat the proteins made from the repeats mightcontribute to ALS.a. What polypeptides are made from the repeat-regiontranscripts?b. According to the RAN translation hypothesis, whyare…
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. The human IGF2 gene is autosomal and maternallyimprinted. Copies of the gene received from themother are not expressed, but copies received fromthe father are expressed. You have found two allelesof this gene that encode two different forms of theIGF2 protein distinguishable by gel electrophoresis.One allele encodes a 60K (Kilodalton) blood protein;the other allele encodes a 50K blood protein. In ananalysis of blood proteins from a couple named Billand Joan, you find only the 60K protein in Joan’sblood and only the 50K protein in Bill’s blood. Youthen look at their children: Jill is producing only the50K protein, while Bill Jr. is producing only the 60Kprotein.a. With these data alone, what can you say about theIGF2 genotype of Bill Sr. and Joan?b. Bill Jr. and a woman named Sara have two children, Pat and Tim. Pat produces only the 60K protein and Tim produces only the 50K protein. Withthe accumulated data, what can you now say aboutthe genotypes of Joan and Bill Sr.?
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