6. The famous geneticist, T.H. Morgan, carried out a series of experiments on linkage mapping in Drosophila. He constructed a series of three-point testcrosses for his mapping studies. What is a three-point testcross (Diagram the genotypes of the parents involved in such a cross)? How many F1 progeny classes are possible from such a cross (show your calculation for your answer)? 1_11_2021 In one such cross, Morgan examined the linkage of three genes v (vermillion eye), cv (crossveinless wings), and ct (cut wing margin). These three are the mutant phenotypes, the wildtype being red eye, crossvein and normal wing margin. From a three-point testcross he obtained the following progeny: + + + AA + > > V + V CV CV +Q CV ct U+ ++++ + ct ct - 580 - 45 - 5 94 CV ct What is the genetic map of these three loci? - 592 40 3 89 3

6. The famous geneticist, T.H. Morgan, carried out a series of experiments on linkage mapping in Drosophila. He constructed a series of three-point testcrosses for his mapping studies. What is a three-point testcross (Diagram the genotypes of the parents involved in such a cross)? How many F1 progeny classes are possible from such a cross (show your calculation for your answer)? 1_11_2021 In one such cross, Morgan examined the linkage of three genes v (vermillion eye), cv (crossveinless wings), and ct (cut wing margin). These three are the mutant phenotypes, the wildtype being red eye, crossvein and normal wing margin. From a three-point testcross he obtained the following progeny: + + + AA + > > V + V CV CV +Q CV ct U+ ++++ + ct ct - 580 - 45 - 5 94 CV ct What is the genetic map of these three loci? - 592 40 3 89 3

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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6. In Drosophila melanogaster, the wild-type eye colour is dark red. A pure-breeding mutant strain with white eyes also exists. When reciprocal crosses are made between (i) a white-eyed male a wild-type female, and (ii) a white-eyed female a wild-type male, the progeny are as follows: (1) P: White-eyed male x red-eyed female F1: red-eyed males and females F2: 100 progeny; 27 red-eved males, 24 white-eyed males, 49 red-eyed females (ii) P: red eyed male x white-eyed female F1: white-eyed males and red-eyed females F2: 100 progeny; 23 red-eved males 26 white-eyed males, 28 red-eyed females, 23 white-eyed females. How do you interpret these data?
4) You design Drosophila crosses to provide recombination data for gene (A), which is located somewhere on the chromosome shown below: Short aristae Long aristae (appendages on head) III Black body Gray body Mutant phenotypes Cinnabar eyes 48.5 57.5 Red eyes 67.0 Vestigial wings Normal wings Brown eyes 104.5 Red eyes Wild-type phenotypes Gene (A) has a recombination frequency of 14% with the vestigial-wing locus and 23% with the brown- eye locus. Where is gene (A) located on this chromosome?
1. The allele G for yellow stigma is completely dominant to green (g). Supposingtwo strains of autotetraploid plants are available and their genotypes are as follows:GGgg – in this plant the gene is close to the centromereGggg – in this plant the gene is far from the centromere If these two plants are crossed:a) provide the gametes that can be obtained from the two plants;b) provide the genotypic and phenotypic ratios of the offspring. 2. Consider the illustration below. Diagram the configuration you would observe at Anaphase I if crossing-over happens within the inversion. (IMAGE ATTACHED)
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…
6). To investigate the genetic control of locomotive behavior in the diploid nematode, Caenorhabditis elegans, eight "wiggly" mutants were isolated, which wiggle in an uncoordinated way rather than smoothly gliding. These eight mutants were crossed together in all possible pairwise combinations, yielding the results summarized in the table above (+ means that all the progeny were wild type, and m means that all the progeny showed the wiggly mutant phenotype). Organize the eight mutations into con lementation groups, each consisting of a group of mutations affecting the same gene. 1 2 3 4 5 6 7 8 1 E N+E 2 3+1 m + m 4 5 + m m E+ + + EE 6 ++E E+ +EE m m + + + + + + + + + m 7 8 ++4 ∞+E +E m m ++ E
2. You are making a genetic map and use a cross to measure the distance between genes H and J as 40cMand the distance between J and M as 20cM. When you measure the distance between genes H and M, you get 50 cM. Do the following (A-C). (A) Draw and label a map of genes H, J, and M. (B) What is the genetic distance between genes H and M? How do you know? (Answer in 1 sentence) (C) Complete the table (right). For each pair of genes, write “yes” or “no” to indicate whether the pair of genes are“linked genes” and/orpart of the same“linkage group”.
4. In Drosophila melanogaster, a yellow-bodied (dark coloured) male with vestigial (underformed) wings is crossed to a wildtype female (brown body, red eyes). The F1 generation are all wildtypes. An F1 male and female are crossed and the F2 progeny consists of 16 vestigial-winged males with yellow bodies, 48 yellow males with normal wings, 15 males with vestigial wings and yellow bodies, 49 wildtype males, 31 vestigial winged females with brown bodies and 97 wildtype females. Explain the inheritance pattern of the 2 genes.
23. In tomatoes, dwarf (d) is recessive to tall (D), and opaque (light-green) leaves (op) are recessive to green leaves (Op). The loci that determine height and leaf color are linked and separated by a distance of 7 m.u. For each of the following crosses, determine the phenotypes and proportions of progeny produced. a. b. C. d. D Op d op X dop d Op Dop d Op D X d op d op d op Op D Op d op Dop D op X d Op d Op
1. In a cross between mice the genotypes AB/ab x ab/ab, what is the recombination frequency if the progeny numbers are 72 AB/ab, 68 ab/ab, 17 Ab/ab, and 21 aB/ab? The alleles are shown for each chromosome, separated by a slash (/). . 2. A cross between fruit files with genotypes Aa Bb × aa bb produces the following progeny: 10 Aa Bb 40 Aa bb 40 aa Bb 10 aa bb Were the parental alleles in the coupling or repulsion configuration? Briefly explain. 3. Briefly describe how twin studies can reveal whether or not the appearance of a trait is strongly influenced by genetics.
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?
31 1. In guinea pig, fur color is determined by one gene, and fur length by another independently segregating gene. The black fur allele (B) is dominant to brown fur allele (b) and the short allele (S) is dominant to long fur allele (s). From progeny listed in the following table, provide the probable genotype for the parents of each cross. Phenotype of Progeny Black short black long brown short Bio3110 Genetics Additional problems (Chapter 2): Parents Black short X Black short Black short X Brown long Black long X Black long 90 17 0 32 16 35 29 14 0 brown long 8 15 2. A mouse with the genotype BbccEeFf is mated with another mouse with BBCcEEFF genotype. What is the probability of obtaining the following genotype in the progeny? a. BBCcEeFF b. BbccEEFf C. BbccEeFF 12 3. Determine the type of gametes that are formed from the following individuals with the given genotype? A. AaBbCc B. AABBCc C. AABbCc
9. Please determine whether the allele responsible for the trait is dominant or recessive. (A) (B) 1 2 10.For a cross between a female color blind carrier and a male color blind person, what is the probability for the female offspring to be color blind? What is the probability for the male offspring to be color blind? Please explain. 11.Consider the genetic map shown below AD Which two alleles have the highest recombination frequency? Which two have the lowest recombination frequency? O Focus ! 72°F DELL F5 F6 PrtScr Insert Hor FZ F8 F9 F10 F11 F12 23 %24 3. 4. 8 E R T