Tetrad analysis in Neurospora is described in Tool Box 6.1. In Neurospora, ser-6 is locate d to the left of ad-8 on the left arm of chromosome VI, as shown in Figure Q6.3; the ce ntromere is shown as the circle at the right end, but the right arm of this chromosome is not shown. A heterozygote is set up, as shown, and is allowed to sporulate. Diagram the ascus and the ascospores that will occur under the following circumstances. a. A cr ossover occurs between the centromere and ad-8 b. A crossover occurs between ser-6 and ad-8 ser-6 ad-8 ser-6 ad Figure Q6.3

Tetrad analysis in Neurospora is described in Tool Box 6.1. In Neurospora, ser-6 is locate d to the left of ad-8 on the left arm of chromosome VI, as shown in Figure Q6.3; the ce ntromere is shown as the circle at the right end, but the right arm of this chromosome is not shown. A heterozygote is set up, as shown, and is allowed to sporulate. Diagram the ascus and the ascospores that will occur under the following circumstances. a. A cr ossover occurs between the centromere and ad-8 b. A crossover occurs between ser-6 and ad-8 ser-6 ad-8 ser-6 ad Figure Q6.3

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 14QP: Variations in Chromosome NumberAneuploidy Describe the process of nondisjunction and explain when it...

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A diploid species has 3 pairs of chromosomes in its somatic cells. In males, the first pair is large submetacentric[1]; the second is medium acrocentric[2], and the third is small telocentric[3]. In females, the first two pairs are like those of the males while the third is large metacentric[4][5], with satellite4 Illustrate the karyograms (drawing/picture of the chromosome) of the following: A triploid cell in females tetrasomic cell in males tetraploid cell in females [1] submetacentric --centrosome is just above the middle of the chromosome [2] acrocentric --centrosome is much higher location than submetacentric so that the “p” arm of the chromosome is much shorter than the q arm [3] telocentric --the centromere is at the end of the chromosome [4] metacentric --centrosome is in the middle of the chromosome; thus the “p-arm” and the “q-arm” or both arms of the chromosome are equal in length [5] satellite-a constriction in an arm of a chromosome, aside…
In an electrophoretic gel across which is applied a powerful electrical alternating pulsed field, the DNA of the haploid fungus Neurospora crassa (n = 7) moves slowly but eventually forms seven bands, which represent DNA fractions that are of different sizes and hence have moved at different speeds. These bands are presumed to be the seven chromosomes. How would you show which band corresponds to which chromosome?
In yeast, LYS5, ADE1, and URA2 are genes required to synthesize lysine, adenine and uracil, respectively. A MATa lys5 ADE1 URA2 haploid was mated to a MATA LYS5 ade1 ura2 haploid to make a triply heterozygous diploid. This diploid was put through meiosis, 100 tetrads were dissected and the spore colonies transferred to medium lacking either lysine, adenine or uracil to determine which spores were prototrophic or auxotrophic for those nutrients. The following results were obtained: LYS5-ADE1 ADE1-URA2 LYS5-URA2 PD NPD Ι 20 22 58 18 20 62 50 8 42 Based on this information, select the statements below that are TRUE. Select 4 correct answer(s) A) The LYS5 and URA2 genes are linked. B) The genotypes of the four spores in the ADE1-URA2 tetratypes is ade1 ura2 ade1 URA2 ADE1 ura2 ADE1 URA2 C) The map distance between ADE1 and URA2 is 51 CM. D) ADE1 and URA2 are likely located on the same chromosome. E) The map distance between LYS5 and URA2 is 29 CM. ☐ F) LYS5 and ADE1 independently assort…
Colchicine is a chemical mutagen that inhibits the spindle formation and prevents anaphase, which retains the cell’s single restitution nucleus (doubled chromosome number). Suppose that an onion (2n=16) is subjected to three consecutive rounds of colchicine treatment, what will be the resulting chromosome number of the treated onion?
For questions 22 through 30, please refer to the pictures below: Normal B B B C D D D D' E E 22 23 24 B D G. Y D M H. B C E 25 26 27 28 B D Break through centromere B B A D 29 30 Identify the type of chromosomal aberration in each number above. Please refer to the choices below. Reciprocal translocation Robertsonian translocation Isochromosome Terminal deletion Interstitial deletion Duplication Pericentric inversion Ring chromosome Marker chromosome Paracentric inversion
A cytogeneticist is studying the cells from an abnormal female monkey. In some cells, she finds that both X-chromosomes are active (i.e. not packaged into a Barr body), although one of the X-chromosomes appears shorter. She also finds that one of the autosomes are packaged as a Barr body, and she suspects that a translocation event might have been involved. By referring to the mechanism of X-chromosome inactivation, explain the observations made by the scientist
8.18 Irradiatioh of Drosophila sperm produces transloca- tions between the X chromosome and autosomes, between the Y chromosome and autosomes, and between different autosomes. Translotations between the X and Y chromosomes are not produced. Explain the absence of X-Y translocations. The birth of this child prompted the Dentons' physician to order a chromosome study of parents and child. The results of the study are shown in the accompanying fig- ure. Chromosome banding was done, and all chromo- somes were normal in these individuals, except some copies of number 6 and number 12. The number-6 and number-12 chromosomes of mother, father, and child are shown in the figure (the number 6 chromosomes are the larger pair): Child Mrs. Denton Mr. Denton a. Does either parent have an abnormal karyotype? If so, which parent has it, and what is the nature of the abnormality? b. How did the child's karyotype arise? (What pairing and segregation events took place in the parents?) e. Why is the child…
In the following schematic drawing of a Holliday junction,one chromatid is shown in red, and the homologous chromatidis shown in blue. The red chromatid carries a dominant allelelabeled A and a recessive allele labeled b, whereas the blue chromatidcarries a recessive allele labeled a and a dominant allelelabeled B. Where would the DNA strands have to be cut to produce recombinantchromosomes? Would they be cut at sites 1 and 3, or at sites2 and 4? What would be the genotypes of the two recombinantchromosomes?
Variations in Chromosome NumberAneuploidy Describe the process of nondisjunction and explain when it takes place during cell division.
A somatic cell has the genotype DdEe. All chromosomes in this organism are metacentric. Show metaphase and the results of mitosis if the D and E locus are linked on the same chromosome in trans configuration. A sexually reproducing organism has the following phenotype DdEeAaTt: The D and E loci are on the same arm of a metacentric chromosome in cis configuration. The A locus is on the long arm of an acrocentric chromosome and the T locus is on a telocentric chromosome. 2.1. What is the haploid number of this organism? 2.2. Using diagrams show a ceii at metaphase of mitosis and show the results of mitosis.
Here is a depiction of the position of several genes on 2 chromosomes, with a dash "-" depicting the position of the centromere. Chromosome A has genes ABCD-EFGHIJ Chromosome B has genes 1234-56789. Please name the kind of rearrangement that would result in the following derivative chromosomes: 12D-EFGHIJ AB4-56789 O Unbalanced reciprocal translocation Unbalanced nonreciprocal translocation Balanced reciprocal translocation Balanced nonreciprocal translocation
a. Manually, using a pencil, draw a cell in anaphase II from an organism in which 2n = 2 and each chromosome is metacentric. b. Given that each G1 nucleus from this organism contains 16 picograms of DNA, how many picograms of chromosomal DNA would you expect in the cell shown here?