4. In Drosophila, three autosomal, recessive mutations are ebony body (e), sepia eye color (s),and hairless bristles (h). A female fly heterozygous at all loci was testcrossed with an ebony,sepia, hairless male; the progeny are shown below. Using the gene symbols stated åbove,answer the following questions.PhenotypeObserved # of offspringEbonysepia, hairlessebony, sepia5753344346 ralHairlessebony, hairlessSepiawild typeebony, sepia, hairlessTotal offspring119.89911000A. Give the genotypes of the flies in the testcross. Write the answer using the gene symbolsstated above and using proper notation.B. Deduce the linkage map showing all distances among the three genes.C. Calculate the interference. Show all work.

In genetics, crossing over occurs in a chromosome, during the prophase stage of meiosis. During this…

4. In Drosophila, three autosomal, recessive mutations are ebony body (e), sepia eye color (s), and hairless bristles (h). A female fly heterozygous at all loci was testcrossed with an ebony, sepia, hairless male; the progeny are shown below. Using the gene symbols stated åbove, answer the following questions. Phenotype Observed # of offspring Ebony sepia, hairless ebony, sepia Hairless ebony, hairless Sepia wild type ebony, sepia, hairless | Total offspring 57 53 344 346 11 6. 89 91 1000 A. Give the genotypes of the flies in the testcross. Write the answer using the gene symbols stated above and using proper notation.

4. In Drosophila, three autosomal, recessive mutations are ebony body (e), sepia eye color (s), and hairless bristles (h). A female fly heterozygous at all loci was testcrossed with an ebony, sepia, hairless male; the progeny are shown below. Using the gene symbols stated åbove, answer the following questions. Phenotype Observed # of offspring Ebony sepia, hairless ebony, sepia Hairless ebony, hairless Sepia wild type ebony, sepia, hairless | Total offspring 57 53 344 346 11 6. 89 91 1000 A. Give the genotypes of the flies in the testcross. Write the answer using the gene symbols stated above and using proper notation.

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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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…
a. In Drosophila, crosses between F1 heterozygotes ofthe form A b / a B always yield the same ratio ofphenotypes in the F2 progeny regardless of the distance between the two genes (assuming completedominance for both autosomal genes). What is thisratio? Would this also be the case if the F1 heterozygotes were A B / a b? (Hint: Remember that inDrosophila, recombination does not take placeduring spermatogenesis.)b. If you intercrossed F1 heterozygotes of the formA b / a B in mice, the phenotypic ratio among the F2progeny would vary with the map distance betweenthe two genes. Is there a simple way to estimate themap distance based on the frequencies of the F2phenotypes, assuming rates of recombination areequal in males and females? Could you estimatemap distances in the same way if the mouse F1heterozygotes were A B / a b?
1.In Drosophila melanogaster body color is controlled by one gene while wing shape is controlled by a second gene. Gray body color is dominant to black body color, and normal wings are dominant to vestigial wings. Flies homozygous for gray body color and vestigial wings are crossed with flies homozygous for black body color and normal wings. A.compare the possible f2 generation genotypes and phenotypes and proportions if these two traits. B.How does your answer change if one of the original parents is homozygous for gray body color and normal wings while the other has black body color and vestigial wings?
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…
Three recessive mutations in that affect eye colour, wing shape and body colourarew, m and b. The following numbers were obtained for testcross progeny in Drosophila. Number Phenotype + m + w + b + + b w m + m b 218 236 168 178 95 101 w + + + 3 w mb 1 (i) Determine the chromosomal composition of the heterozygous female parent. Construct a genetic map of the linkage group(s) these genes occupy. Show the order and give the map distances between the genes. (ii)
Male Drosophila expressing the autosomal recessivemutations sc (scute), ec (echinus), cv (crossveinless),and b (black) were crossed to phenotypically wildtype females, and the 3288 progeny listed wereobtained. (Only mutant traits are noted.)653 black, scute, echinus, crossveinless670 scute, echinus, crossveinless675 wild type655 black71 black, scute73 scute73 black, echinus, crossveinless74 echinus, crossveinless87 black, scute, echinus84 scute, echinus86 black, crossveinless83 crossveinless1 black, scute, crossveinless1 scute, crossveinless1 black, echinus1 echinusa. Diagram the genotype of the female parent.b. Map these loci.c. Do the data provide evidence of interference?Justify your answer with numbers.
1. Please consider the following pedigree. I 1 II 1 a) Assume that colour is controlled by a single sex-influenced gene where green is expressed preferentially in males. Individuals I-1 and I-2 are homozygous for red and green respectively. Which individual/s in generation II will be red? b) If colour is a controlled by cytoplasmic DNA, which individual/s in generation II will be green?
In Drosophila, three autosomal genes have the following map:20 m.u. 10 m.u.a b ca. Provide the data, in terms of the expected numberof flies in the following phenotypic classes, whena+ b+ c+/ a b c females are crossed to a b c / a b c males. Assume 1000 flies are counted and that nointerference exists in this region.a+ b+ c+a b ca+ b ca b+ c+a+ b+ ca b c+a+ b c+a b+ cb. If the cross was reversed, such that a+ b+ c+ / a b cmales are crossed to a b c / a b c females, howmany flies would you expect in the same phenotypic classes?
Homozyogous wild type male Drosophila PPQQRRSSTTUUVV (all linked) are irradiated to induce the formation of chromosomal deletions and then mated with homozygous recessive females. In several of these matings a unique pattern of pseudodominance could be correlated with the loss of specific polytene chromosome bands, as shown in the table... Cross Chromosomal Bands Deleted Pattern of Pseudodominance PqRs TuV 1 2 3 4 5 5-6 1-2 3-5 6-8 1-3 PQRSTUV PqrSTUV PQRSTUV pQrSTUV In which chromosomal band is gene R located? A. 3 OB. 4 OC. 2 D.8 O E. none of these answers are correct
5 f There are two genes that determine the coat colour expression in dogs: eumelanin and merle. These genes are located on two separate chromosomes. For the eumelanin gene, black coat colour (E) is dominant over red coat colour (e). The merle gene controls the degree to which these coat colours are expressed through incomplete dominance. The following table describes the merle gene expression. Genotype MM Mm mm Phenotype White AAY Half colour (Grey or light red) Full colour (Black or Red) 1. If a dog breeder wants to determine the unknown genotype of a dog, what colour of dog must she use as a testcross? 2. A white dog was testcrossed, and all of the puppies had light red coats. What is the genotype of the white dog? Use a Punnett square to show your work. Hint - When a trait is controlled by two genes, an individual's genotype consists of 4 letters. = = = B I 123 ||| 14 E E I ос C GO * ●● ● ●0 00 00 00 ✓ C U up X₂ x²
Drosophila females heterozygous for each of three recessive autosomal mutations with independent phenotypic effects [thread antennae (th), hairy body (h), andscarlet eyes (st)] were testcrossed to males showingall three mutant phenotypes. The 1000 progeny of thistestcross werethread, hairy, scarlet 432wild type 429thread, hairy 37thread, scarlet 35hairy 34scarlet 33a. Show the arrangement of alleles on the relevantchromosomes in the triply heterozygous females.b. Draw the best genetic map that explains these data.c. Calculate any relevant interference values
Please explain how you do this question step by step I am very confused! thank you:) You have three independent mutant alleles in the Drosophila gene no-antenna: nan1, nan2 and nan3. You determine the phenotype of Drosophila that are heterozygous for the three alleles (heterozygous for a wild-type allele and a mutant allele), and that are homozygous for the three mutant alleles. The antenna is composed of three segments that are followed at the distal end by a feathery arista (that is the antenna is composed of three segments and an arista). Allele nan1 nan2 nan3 heterozygous Wild-type No arista Wild-type homozygous No arista No antenna No antenna nan1 is a __x__ allele, nan2 is a __y__ allele, and nan3 is a __z__ allele. X Y Z A Dominant negative Null Hypomorphic B Null Dominant negative Hypomorphic C Null Hypomorphic Dominant negative D Hypomorphic Dominant negative Null E Dominant negative Hypomorphic Null Referencing the table above, select the…