Concept explainers
a.
To determine: The implication of the results regarding the location of the stopper mutation in the genome.
Introduction. The different forms of an allele in two organisms of the species can result in changes in their appearance even though their genetic composition is highly similar. These are gene polymorphisms that account for the change in the appearance of genetically similar organisms.
b.
To determine: The progeny and proportions predicted in octads from the cross with a mutation in nic3 located in chromosome 6.
Introduction. The genes are the sequence of
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
Introduction to Genetic Analysis
- Consider a maize plant: Genotype C/cm ; Ac/Ac+ where cm is an unstable colorless allele caused by Ds insertion. What phenotypic ratios would be produced and in what proportions when this plant is crossed with a mutant c/c Ac+/Ac+? Assume that the Ac and c loci are unlinked, that the chromosome-breakage frequency is negligible, and the C allele encodes pigment production.arrow_forwardIn the fungus Neurospora, a strain that is auxotrophic for thiamine (mutant allele t) was crossed with a strain that isauxotrophic for methionine (mutant allele m). Linear asci were isolated and classified into the following groups: a. Determine the linkage relations of these two genes to their centromere(s) and to each other. Specify distances in map units. b. Draw a diagram to show the origin of the ascus type with only one single representative (second from right).arrow_forwardAn Hfr strain is used to map three genes in an interrupted mating experiment. The cross is Hfr/a+b+c+ rif x F-a-b-c- rifr (note that rifr is resistance to the antibiotic rifampicin). The a+ gene is required for the biosynthesis of nutrient A, the b+ gene for nutrient B, and the c+ gene for nutrient C. The cross is initiated at time=0. At various times, the mating mixture is plated out on three different types of medium. Each plate contains minimal medium (MM) plus rifampicin, plus specific supplements that are listed in the table below. The results for each time interval are shown as the number of colonies growing on each plate.An Hfr strain is used to map three genes in an interrupted mating experiment. The cross is Hfr/a+b+c+ rif x F-a-b-c- rifr (note that rifr is resistance to the antibiotic rifampicin). The a+ gene is required for the biosynthesis of nutrient A, the b+ gene for nutrient B, and the c+ gene for nutrient C. The cross is initiated at time=0. At various times, the…arrow_forward
- QUESTION 11 The location of five deletions have been mapped to a Drosophila chromosome, as shown in the following deletion map. Recessive mutations a, b, c, d and e are known to be located in the same region as the deletions but the order of the mutations on the chromosome is not known. Drosophila Chromosome Deletion 1 Deletion 2 Deletion 3 Deletion 4 Deletion 5 When flies homozygous for the recessive mutation are crossed with flies heterozygous for the deletions, the following results are obtained in which "m" represents recovery of flies with a mutant phenotype and "+" represents recovery of only flies with a wildtype phenotype. Use the data from the table below to determine the order of the genes (a-e) on the chromosome. Mutants Deletions a b C d e 1 + + + + m 2 + m + m 3 m m m m 4 + + m + + 5 m + m m + What is the gene order for these five genes? Please do not separate the letters representing the mutations with spaces or punctuation (e.g. LMNOP)arrow_forwardMultiple crosses were made between true-breeding lines of black and yellow Labrador retrievers. All the F1 progeny were yellow. When these progeny were intercrossed, they produced an F2 consisting of 121 yellow, 9 black and 30 chocolate. What epistatic ratio and what kind of epistasis is approximated in the F2? Propose a biochemical pathway for coat color in Labrador retrievers based on the type of epistasis. Correlate each genotype with the phenotype that would occur in your pathway. Also show the frequency of each genotype. A-B- A-bb aaB- aabbarrow_forwardConsider two maize plants:a. Genotype C/c m ; Ac/Ac+, where cm is an unstable allele caused by a Ds insertionb. Genotype C/c m, where cm is an unstable allele caused by Ac insertionWhat phenotypes would be produced and in what proportions when (1) each plant is crossed with a basepair-substitution mutant c/c and (2) the plant in part a is crossed with the plant in part b? Assume that Ac and c are unlinked, that the chromosome-breakage frequency is negligible, and that mutant c /C is Ac+.arrow_forward
- A cross between a wild-type fruit fly strain and various true-breeding mutant strains (all at a single locus) for bristle mutations resulted in the following phenotypes: Mutant Bristle Phenotype 1 0.20 shorter 2 0.30 longer 3 0.75 shorter 4 bent and damaged, non-functional 5 no bristlesarrow_forwardA bacterial strain with genotype his− leu− thr− is transformed with DNA from a strain that is his+ leu+ thr+. A few leu+ thr+ cells and a few his+ thr+ cells are found, but no his+ leu+ cells are observed. Which genes are farthest apart?arrow_forwardIn a three-point mapping experiment for the genes a-w-ec, the following percentages of events are observed: NCO events: 57%; SCO events between a and w: 18%; SCO events between w and ec: 22%; DCO events: 2% Assuming that w is in the middle, what is the map distance between w and ec? What is the map distance between a and w? Draw the map.arrow_forward
- Recombination frequencies between four genetically-linked loci in corn are shown in the following table: Loci Recombination Frequency (%) R and Q 45 W and Q 60 R and W 15 Q and L 10 L and R 35 What is the order of the genes on the chromosome? (note: The same answer can be represented forward or backwards. e.g. A B C D = D C B A) RQWL LQWR QWLR QRLW WRLQarrow_forwardA Drosophila strain with two mutated phenotypes was crossed with a wild-type Drosophila strain. The wild-type phenotypes were present in all of the F1 flies. The F1 flies were bred with one another. The F2 generation, on the other hand, did not have the predicted 9:3:3:1 phenotypic ratio. Explain why these outcomes occurred.arrow_forwardRecombination frequencies between four genetically-linked loci in corn are shown in the following table: Loci Recombination Frequency (%) L and Q 20 Q and R 50 R and L 30 Q and W 13 L and W 7 What is the order of the genes on the chromosome? (note: The same answer can be represented forward or backwards. e.g. A B C D = D C B A) LQWR RQWL LRQW QRLW RLWQarrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education