The following results are ordered tetrad pairs from a cross between strain cd and strain ++: Tetrad Class 2 3. 4 5 7 c+ cd + d c + c+ c+ c d c d c d + d + + + + C+ C+ +d + + c d c d c d + d ++ c+ + d + + +d + d ++ + + 45 15 2 4 3 They are summarized by tetrad class. (a) Name the ascus type of each class from 1 to 7 (P, NP or T). The data support the conclusion that the c and d loci are linked. State the evidence in support of this conclusion. (b) Calculate the gene-centromere distance for each locus.

The following results are ordered tetrad pairs from a cross between strain cd and strain ++: Tetrad Class 2 3. 4 5 7 c+ cd + d c + c+ c+ c d c d c d + d + + + + C+ C+ +d + + c d c d c d + d ++ c+ + d + + +d + d ++ + + 45 15 2 4 3 They are summarized by tetrad class. (a) Name the ascus type of each class from 1 to 7 (P, NP or T). The data support the conclusion that the c and d loci are linked. State the evidence in support of this conclusion. (b) Calculate the gene-centromere distance for each locus.

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter6: Cytogenetics: Karyotypes And Chromosome Aberrations

Section: Chapter Questions

Problem 24QP: A geneticist discovers that a girl with Down syndrome has a Robertsonian translocation involving...

See similar textbooks

Similar questions

Neurospora of genotype a + c are crossed withNeurospora of genotype + b +. (Here, + is shorthandfor the wild-type allele.) The following tetrads areobtained (note that the genotype of the four sporepairs in an ascus are listed, rather than listing alleight spores):a + c a b c + + c + b c a b + a + ca + c a b c a + c a b c a b + a b c+ b + + + + + b + + + + + + c + + ++ b + + + + a b + a + + + + c + b +137 141 26 25 2 3a. In how many cells has meiosis occurred to yieldthese data?b. Give the best genetic map to explain these results.Indicate all relevant genetic distances, both betweengenes and between each gene and the centromere.c. Diagram a meiosis that could give rise to oneof the three tetrads in the class at the far right inthe list
The diploid that resulted from mating these two haploids would have which of the following auxotrophies? Select all that apply.Strain 1: MATa ura3-52 met15Δ0 leu2Δ0 Strain 2: MATalpha ura3-52 met15Δ0 trp1Δ63 a.) histidine b.) tryptophan c.) uracil d.) lysine e.) leucine f.) methionine
A Neurospora cross was made between a strain that carried the mating-type allele A and the mutant allele arg-1and another strain that carried the mating-type allele aand the wild-type allele for arg-1 (+). Four hundred linear octads were isolated, and they fell into the sevenclasses given in the table below. (For simplicity, they areshown as tetrads.)a. Deduce the linkage arrangement of the mating-typelocus and the arg-1 locus. Include the centromere orcentromeres on any map that you draw. Label all intervalsin map units.b. Diagram the meiotic divisions that led to class 6. Labelclearly
The recombination frequency in a cross can never exceed 50%. Explain why is this limit?
Fill the punnet square for just cross 2 and then do the chi square by using the observed values of cross 2 given in the picture:
Homozygous wild-type male mice (AA BB CC) were crossed with triplemutant female mice (aa bb cc), forming an F1 generation with the followinggenotype (Aa Bb Cc). The F1 males were crossed with triple mutantfemales, forming the following F2 phenotypes”“a B c” 3“A b C” 3“a b c” 8“A B c” 5“a b C” 5“A B C” 8“a B C” 6“A b c” 6 44 Determine the sequence of the genes
From a cross between e+ f+ g+ and e− f − g− strains ofNeurospora, recombination between these linkedgenes resulted in a few octads containing the followingordered set of spores:e+ f+ g+e+ f+ g+e+ f − g+e+ f − g+e− f − g−e− f − g−e− f − g−e− f − g−a. Where was recombination initiated?b. Did crossing-over occur between genes e and g?Explain.c. Why do you end up with 2 f+ : 6 f − but 4 e+: 4 e−and 4g+: 4g−?d. Could you characterize these unusual octads as MIor MII for any of the three genes involved?Explain.
From a series of two-point crosses, the following mapdistances were obtained for the syntenic genes A, B,C, and D in peas:B ↔ C 23 m.u.A ↔ C 15 m.u.C ↔ D 14 m.u.A ↔ B 12 m.u.B ↔ D 11 m.u.A ↔ D 1 m.u.Chi-square analysis cannot reject the null hypothesis of no linkage for gene E with any of theother four genes.a. Draw a cross scheme that would allow you todetermine the B ↔ C map distance.b. Diagram the best genetic map that can be assembled from this data set.c. Explain any inconsistencies or unknown features inyour map.d. What additional experiments would allow you toresolve these inconsistencies or ambiguities?
When the interrupted mating technique was used with five different strains of Hfr bacteria, the following orders of gene entry and recombination were observed. On the basis of these data, draw a map of the bacterial chromosome. Do the data support the concept of circularity?Hfr Strain Order1 T C H R O2 H R O M B3 M O R H C4 M B A K T5 C T K A B
An individual is heterozygous for a reciprocal translocation, with the following chromosomes: A • B C D E F A • B C V W X R ST • U D E F R ST • U V W X Q. Explain why the fertility of this individual is likely to be less than the fertility of an individual without a translocation.
The genotype of EB27 and EB67 are unknown. Based on pedigree, what are the most likely genotype of each individual?
Based on your knowledge of genetics, how would you determine whether kanamycin or BASTA-resistant T2 seedlings are homo- or hemizygous for Bar or NPTII?