2. Drosophila females heterozygous for three recessive x-linked markers y (yellow bodies), ct (cut wings), and m (miniature wings) were crossed to y ct m males and the following progeny were obtained. F1 Phenotype Yellow, cut, miniature Wildtype Yellow Cut, miniature miniature Number cut 60 63 20 13 Yellow, cut 15 Yellow, miniature 5 22 2 a) F1 Genotype b) Recombinant or Parental? c) SCO, DCO, or NONE? a) Fill in the table with the genotypes of each progeny type, use + to indicate wildtype/dominant traits, show separate homologues. b) In the table, identify whether each progeny type is Recombinant (R) or Parental (P). c) In the table, identify whether each progeny type results from a single crossover (SCO), a double crossover (DCO), or no crossing over (NONE). d) Diagram the parental cross, clearly indicating allelic contributions from each homologue of parental flies. Heterozygous wild-type Female Fly X Hemizygous mutant Male fly // // e) Draw the genetic map showing correct order and relative distance (include units) between the genes. Show all calculations for recombination frequencies. f) Calculate the coefficient of confidence and interference values. Show all calculations

2. Drosophila females heterozygous for three recessive x-linked markers y (yellow bodies), ct (cut wings), and m (miniature wings) were crossed to y ct m males and the following progeny were obtained. F1 Phenotype Yellow, cut, miniature Wildtype Yellow Cut, miniature miniature Number cut 60 63 20 13 Yellow, cut 15 Yellow, miniature 5 22 2 a) F1 Genotype b) Recombinant or Parental? c) SCO, DCO, or NONE? a) Fill in the table with the genotypes of each progeny type, use + to indicate wildtype/dominant traits, show separate homologues. b) In the table, identify whether each progeny type is Recombinant (R) or Parental (P). c) In the table, identify whether each progeny type results from a single crossover (SCO), a double crossover (DCO), or no crossing over (NONE). d) Diagram the parental cross, clearly indicating allelic contributions from each homologue of parental flies. Heterozygous wild-type Female Fly X Hemizygous mutant Male fly // // e) Draw the genetic map showing correct order and relative distance (include units) between the genes. Show all calculations for recombination frequencies. f) Calculate the coefficient of confidence and interference values. Show all calculations

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter13: Genes, Chromosomes, And Human Genetics

Section: Chapter Questions

Problem 8TYK: Another gene in Drosophila determines wing length. The dominant wild-type allele of this gene...

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In cats, the genotype AA produces tabby fur color; Aa is also a tabby, and aa is black. Another gene at a different locus is epistatic to the gene for fur color. When present in its dominant W form (WW or Ww), this gene blocks the formation of fur color and all the offspring are white; ww individuals develop normal fur color. What fur colors, and in what proportions, would you expect from the cross AaWw Aa Ww?
In addition to the two genes in problem 4, assume you now study a third independently assorting gene that has the alleles C and c. For each of the following genotypes, indicate what types of gametes will be produced: a. AA BB CC b. Aa BB Cc c. Aa BB cc d. Aa Bb Cc
The following pedigree shows the pattern of inheritance of red green color blindness in a family. Females are shown as circles and males as squares; the squares or circles of individuals affected by the trait are filled in red. What is the chance that a son of the third-generation female indicated by the arrow will be color-blind if the father is a normal man? If the father is color-blind?
Choose the statement that is incorrect. a. A son can inherit a recessive allele on an X chromosome from either parent. b. An individual may inherit three or more of each type of chromosome characteristic or the species, a condition called polyploidy. c. A female child inherits one X chromosome from her mother and one from her father. d. Pedigree analysis can be used to determine a future childs chance of being born with achcondroplasia.
9. Red-green color blindness is inherited as an X-linked recessive (Xc). If a color-blind man marries a woman who is heterozygous for normal vision, what would be the expected phenotypes of their children with reference to this character? In your answer, specify in your phenotype descriptions the gender of the children. (For example, don’t just say 75% of the children would be colorblind – you would instead say 100 % of the daughters would be colorblind and 50% of the sons would be colorblind. Note that this is not a correct answer; it is just to give you an idea of how to explain the correct phenotypes of the cross.)___
2. a. A Drosophila male from a true-breeding stockwith scabrous eyes was mated with a female from atrue-breeding stock with javelin bristles. Both scabrous eyes and javelin bristles are autosomal recessive mutant traits. The F1 progeny all had normaleyes and bristles. F1 females from this cross weremated with males with both scabrous eyes andjavelin bristles. Write all the possible phenotypicclasses of the progeny that could be produced from the cross of the F1 females with the scabrous, javelin males, and indicate for each class whether it is arecombinant or parental type.b. The cross in part (a) yielded the following progeny:77 scabrous eyes and normal bristles; 76 wild type(normal eyes and bristles); 74 normal eyes andjavelin bristles; and 73 scabrous eyes and javelinbristles. Are the genes governing these traits likelyto be linked, or do they instead assort independently? Why?c. Suppose you mated the F1 females from the crossin part (a) to wild-type males. Why would thiscross fail…
I. Male Drosophila from a true-breeding wild-typestock were irradiated with X-rays and then mated withfemales from a true-breeding stock carrying the following recessive mutations on the X chromosome:yellow body (y), crossveinless wings (cv), cut wings(ct), singed bristles (sn), and miniature wings (m).These markers are known to map in the order:y - cv - ct - sn - mMost of the female progeny of this cross were phenotypically wild type, but one female exhibited ct and snphenotypes. When this exceptional ct sn female wasmated with a male from the true-breeding wild-typestock, twice as many females as males appearedamong the progeny.a. What is the nature of the X-ray-induced mutationpresent in the exceptional female?b. Draw the X chromosomes present in the exceptional ct sn female as they would appear duringpairing in meiosis.c. What phenotypic classes would you expect to seeamong the progeny produced by mating the exceptional ct sn female with a normal male from a truebreeding wild-type…
0. In Drosophila, the gene for cinnabar eye color is onchromosome 2, and the gene for scarlet eye color is onchromosome 3. A fly homozygous for both recessivecinnabar and scarlet alleles (cn/cn; st/st) is white-eyed.a. If male flies (containing chromosomes with thenormal gene order) heterozygous for cn and st allelesare crossed to white-eyed females homozygous forthe cn and st alleles, what are the expected phenotypes and their frequencies in the progeny?b. One unusual male heterozygous for cn and st alleles,when crossed to a white-eyed female, produced onlywild-type and white-eyed progeny. Explain the likelychromosomal constitution of this male.c. When the wild-type F1 females from the cross withthe unusual male were backcrossed to normal cn/cn;st/st males, the following results were obtained:wild type 45%cinnabar 5%scarlet 5%white 45%Diagram a genetic event at metaphase I that couldproduce the rare cinnabar or scarlet flies among theprogeny of the wild-type F1 females.
13. A dominant x-linked allele (B) gives normal color vision but the recessive allele (b) causes red-green color blindness.A. What is the genotype of a man with normal color vision whose father was color- blind? B. What is the genotype of a woman with normal color vision whose father was color-blind? C. If a woman who is colorblind marries a man with normal vision, what would you expect for the genotypes and phenotypes of their children? D. If a man is color-blind, which parent did he inherit the gene from? Explain your answer. E. Which parent does a man get all his x-linked genes from? F. If a woman is color-blind, what do you know about the genotypes and phenotypes of her parents? G. Are men more likely than women to get a genetic disease which is x-linked and dominant? Are they more likely to get a disease that is x-linked and recessive? Explain your answers. H. Can a man with normal color vision have a colorblind daughter? Explain your answer.…
7. In rabbits, a locus involved in the control of coat colour may be occupied by any of fouralleles: Full colour (C), Sepia (ck), Cream (cd), or Albino (ca). A geneticist counted the numberof Full colour (C), Sepia (ck), Cream (cd) and Albino coat offspring resulting after crossesbetween Sepia (ck) and Cream (cd) coloured coated parents. The results were as follows.• Full colour (C): 152• Sepia (ck): 53• Cream (cd): 39• Albino (ca): 6Mendelian inheritance of this trait predicts that the ratio of Full colour (C) to Sepia (ck) to Cream(cd) to Albino (ca) should be 9:3:3:1. Do the experimental results support this mode ofinheritance?
3) A. How are the following proteins involved in cell division: condensing, cohesin, kinetochore complex, tubulin? B. Why does phenotype not always reveal genotype? C. How can Mendel's postulates of segregation and independent assortment be explained by meiosis? D. Explain the genotypic and phenotypic ratios predicted when performing a monohybrid and a dihybrid cross of heterozygotes? E. How can you use the product rule and sum rule to calculate the probability of a particular genotype resulting from crossing parents of specific genotypes?
6. A person is simultaneously heterozygous for two autosomal genetic traits. One is a recessive condition foralbinism (alleles A and a); this albinism gene is foundnear the centromere on the long arm of an acrocentricautosome. The other trait is the dominantly inheritedHuntington disease (alleles HD and HD+). TheHuntington gene is located near the telomere of oneof the arms of a metacentric autosome. Draw all copies of the two relevant chromosomes in this person asthey would appear during metaphase of (a) mitosis,(b) meiosis I, and (c) meiosis II. In each figure, labelthe location on every chromatid of the alleles forthese two genes, assuming that no recombinationtakes place.