The rosy (ry) gene of Drosophila encodes an enzymecalled xanthine dehydrogenase. Flies homozygous forry mutations exhibit a rosy eye color. Heterozygousfemales were made that had ry41 Sb on one homologand Ly ry564 on the other homolog, where ry41 andry564 are two independently isolated alleles of ry. Ly[Lyra (narrow) wings] and Sb [Stubble (short) bristles] are dominant mutant alleles of genes to the left and right of ry, respectively. These females arenow mated to males homozygous for ry41. Out of100,000 progeny, 8 have wild-type eyes, Lyra wings, andStubble bristles, while the remainder have rosy eyes.a. What is the order of these two ry mutations relativeto the flanking genes Ly and Sb?

The rosy (ry) gene of Drosophila encodes an enzymecalled xanthine dehydrogenase. Flies homozygous forry mutations exhibit a rosy eye color. Heterozygousfemales were made that had ry41 Sb on one homologand Ly ry564 on the other homolog, where ry41 andry564 are two independently isolated alleles of ry. Ly[Lyra (narrow) wings] and Sb [Stubble (short) bristles] are dominant mutant alleles of genes to the left and right of ry, respectively. These females arenow mated to males homozygous for ry41. Out of100,000 progeny, 8 have wild-type eyes, Lyra wings, andStubble bristles, while the remainder have rosy eyes.a. What is the order of these two ry mutations relativeto the flanking genes Ly and Sb?

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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Gene A, which encodes alcohol dehydrogenase, is labeled with a red fluorophore in a FISH experiment with one chromosome of a homologous pair, with results shown below. Gene B is labeled in green and encodes Notch2NL, a gene which may help to explain brain size differences between humans and chimpanzees, and which with increased dosage, may lead to a condition referred to as macrocephaly (enlarged head circumference sometimes associated with learning disabilities). What can you infer about these two genes given the results seen below?
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The HbβS(sickle-cell) allele of the human β-globingene changes the sixth amino acid in the β-globinchain from glutamic acid to valine. In HbβC, the sixthamino acid in β-globin is changed from glutamic acidto lysine. What would be the order of these two mutations within the map of the β-globin gene?
In mice, the trait for high cholesterol is specified by a dominant allele designatedHC, whereas the wild-type allele for normal cholesterol levels is designated hc.Black fur is specified by a recessive allele designated bl, whereas the wild-typeallele which gives brown fur is designated BL. The genes for both of these traitsare 30cM apart on the same autosome. A brown female (#1) with high cholesterolis mated to a black male (#2) with normal cholesterol. The progeny from this crossinclude a brown male (#3) with high cholesterol and a black female (#4) withnormal cholesterol. Mouse #3 is mated to a brown female (#5) with normalcholesterol. If 4 mice are produced from this cross, what is the probability that all 4will have brown fur?
In Drosophila, a female fly is heterozygous for three mutations, Bareyes (B), miniature wings (m), and ebony body (e). Note that Bar isa dominant mutation. The fly is crossed to a male with normal eyes,miniature wings, and ebony body. The results of the cross are asfollows.111 miniature29 wild type117 Bar26 Bar, mimatue101 Bar, ebony31 Bar, miniature, ebony35 ebony115 miniature, ebonyInterpret the results of this cross. If you conclude that linkage isinvolved between any of the genes, determine that map distance(sbetween them.
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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?
Most black bears (Ursus americanus) are black or brown in color. However, occasional white bears of this species appear in some populations along the coast of British Columbia. Kermit Ritland and his colleagues determined that white coat color in these bears results from a recessive mutation (G) caused by a single nucleotide replacement in which guanine substitutes for adenine at the melanocortin-1 receptor locus (mc1r), the same locus responsible for red hair in humans (K. Ritland, C. Newton, and H. D. Marshall. 2001. Current Biology 11:1468–1472). The wild-type allele at this locus (A) encodes black or brown color. Ritland and his colleagues collected samples from bears on three islands and determined their genotypes at the mc1r locus: Genotype Number AA 42 AG 24 GG 21 a. What are the frequencies of the A and G alleles in these bears? b. Give the genotypic frequencies expected if the population is in Hardy– Weinberg equilibrium. c. Use a chi-square test to compare the number of…
Drosophila females heterozygous for three recessive mutations, a, b, and c , were crossed to males homozygous for all three mutations.The cross yielded the following results: in the image Q. Construct a linkage map showing the correct order of these genes and estimate the distances between them.
In 2018, scientists published a paper describing three unusual human families where some individuals ex- hibited biparental inheritance of mitochondria. The researchers made this discovery by determining the base-pair sequences of the mtDNAs of many individ- uals in each family, and the results are shown in the three pedigree diagrams that follow. The filled-in (blue) symbols represent family members who inher- ited mtDNAs from both of their parents. a. The scientists who authored this study suggest that the data hint at the following model: The transmis- sion of paternal mtDNA to the zygote depends on transmission of an autosomal dominant mutant al- lele through the male germ line. Which aspects of the pedigrees are consistent with this hypothesis? b. The precise mechanism by which paternal mitochon- dria are normally excluded from human zygotes is unknown. If the hypothesis in part (a) is correct, what do these results suggest about the mechanism?
Star eye A peculiar eye condition known as "star” is manifested as a dominant gene in Drosophila. Its recessive allele R* produces the normal eye of wild type. The expression of R can be suppressed by the dominant allele of another locus, Ru-R. Ru-R*, as the recessive allele of the said locus, has no inhibitory effect on R*. When a normal-eyed male of genotype Ru-R Ru-R RR is crossed to a homozygous wild-type female of genotype Ru-R* Ru-R* R*R*, what phenotypic ratio is expected in the F2?