You are interested in studying position effect variegation in Drosophila using the chromosome depicted below: Deactivation of the w+ gene gives a white eye phenotype and deactivation of the rst+ gene gives a rough eye phenotype; the normal phenotypes are red and smooth. Because the rst+ and w+ genes have now been placed close to a heterochromatic domain, some sections (or sectors) of the eye display mutant phenotypes due to gene deactivation while others display the normal, wild type phenotype. Which phenotype would you not expect to see rst w Inverted X chromosome white smooth eye sectors white rough eye sectors red smooth eye sectors red rough eye sectors

You are interested in studying position effect variegation in Drosophila using the chromosome depicted below: Deactivation of the w+ gene gives a white eye phenotype and deactivation of the rst+ gene gives a rough eye phenotype; the normal phenotypes are red and smooth. Because the rst+ and w+ genes have now been placed close to a heterochromatic domain, some sections (or sectors) of the eye display mutant phenotypes due to gene deactivation while others display the normal, wild type phenotype. Which phenotype would you not expect to see rst w Inverted X chromosome white smooth eye sectors white rough eye sectors red smooth eye sectors red rough eye sectors

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter11: Genome Alterations: Mutation And Epigenetics

Section: Chapter Questions

Problem 20QP: The cystic fibrosis gene encodes a chloride channel protein necessary for normal cellular functions....

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The locations of six deletions have been mapped to a Drosophila chromosome, as shown in the following deletion map. Recessive mutations a, b, c, d, e, and f are known to be located in the same region as the deletions, but the order of the mutations on the chromosome is not known. (refer image for contination )
The locations of six deletions have been mapped to a Drosophila chromosome, as shown in the following deletion map. Recessive mutations a, b, c, d, e, and f are known to be located in the same region as the deletions, but the order of the mutations on the chromosome is not known.
Consider the following variations in Drosophila melanogaster, relative to the wild-type: White eyes are a recessive trait—the gene of which is found in Chromosome I (X). Vestigial wings are a recessive trait—the gene of which is found in Chromosome II. Aristapedia is a dominant trait—the gene of which is found in Chromosome III. Being homozygous for this condition is lethal. Cross the following mutant females with a wild-type (homozygous) male. Show the Punnett square and obtain the genotypic and phenotypic ratios of the first filial generation (F1). Female with white eyes Q4: Show the Punnett squares and obtain the genotypic and phenotypic ratios of the first filial generation (F1) and second filial generation (F2) of the following crosses. Note: The F2 generation can be obtained by crossing one male and one female from the F1 generation. Female with white eyes and vestigial wings and wild-type male
The cystic fibrosis gene encodes a chloride channel protein necessary for normal cellular functions. Let us assume that if at least 5% normal channels are present, the affected individual has mild symptoms of cystic fibrosis. Having less than 5% normal channels produces severe symptoms. At least 50% of the channels must be expressed for the individual to be phenotypically normal. This gene has various mutant recessive alleles: Predict the percent of functional channels and severity of symptoms for the following genotypes: a. heterozygous for CF100 b. homozygous for CF100 c. heterozygous, with one copy of CF100 and one of CF3 d. heterozygous, with one copy of CF1 and one copy of CF3
Researchers have exploited Minute mutations in orderto study the phenotypes associated with recessive lethal mutations (l−) that decrease the rate of cell divisionand thus make only very tiny homozygous mutant clones that are difficult to analyze. Many differentstrains of Drosophila carry dominant loss-of-functionMinute (M) mutations in a variety of genes encodingribosomal protein subunits. The M genes are haploinsufficient; flies with only one wild-type M+ gene copyhave a slower pace of cell division, and thus prolongeddevelopment and subtle morphological abnormalities.To circumvent the tiny clone problem, researchersgenerate GFP-marked homozygous l−/ l− clones thatare also M+/ M+, in flies that are l−/ l+ and M−/ M+.The loss of the Minute mutation only in cells withinthe clone gives the l−/ l− cells a growth advantageover their neighbors, enabling the mutant clone togrow large enough to study. Diagram chromosomesthat could be used to generate such clones
In Drosophila, one of the genes controlling wing length is located on the X chromosome. A recessive mutant allele of this gene makes the wings miniature—hence, its symbol m; the wild-type allele of this gene, m_, makes the wings long. One of the genes controlling eye color is located on an autosome. A recessive mutant allele of this gene makes the eyes brown—hence, its symbol bw; the wildtype allele of this gene, bw_, makes the eyes red. Miniature-winged, red-eyed females from one true-breeding strain were crossed to normal-winged, brown-eyed males from another true-breeding strain. 1. Predict the phenotypes of the F1 flies. 2. If these flies are intercrossed with one another, what phenotypes will appear in the F2, and in what proportions?
Here are schematic diagrams of mutant Drosophila larvae. The left side of each pair shows a wild-type larva, with gray boxes showing the sections that are missing in the mutant larva. Which type of gene is defective in each larva: a gap gene, a pair-rule gene, or a segment-polarity gene?
In Drosophila subobscura, the presence of a recessive gene called grandchildless (gs) causes the offspring of homozygous females, but not those of homozygous males, to be sterile. Can you offer an explanation as to why females and not males are affected by the mutant gene?
Suppose a researcher has three different Drosophila strains that have mutations in the bicoid gene called bicoid-A, bicoid-B, and bicoid-C; the wild type is designated bicoid +. To study these mutations, phenotypically normal female flies that are homozygous for the given bicoid mutation were obtained, and their oocytes were analyzed using a Northern blot to determine the size and/or amount of the bicoid mRNA and in situ hybridization to determine the bicoid mRNA location within the oocyte. A wild-type strain was also analyzed as a control. In both cases, the probe was complementary to the bicoid mRNA and the results are shown below. (Anterior is on the left; posterior is on the right.) Northern blot 1 2 - 3 4 In situ hybridization Wild type Lane 1. Wild type (bicoid*) Lane 2. bicoid-A Lane 3. bicoid-B Lane 4. bicoid-C bicoid-B bicoid-A bicoid-C Which mutation is likely to cause the embryo to develop two "anterior" ends? bicoid-B Obicoid-A bicoid-C
. In Drosophila melanogaster many eye color mutations are known. One such recessive mutation is called brown (bw) and gives brown eyes instead of the wild type dark red eyes. Another recessive mutation is scarlet (st) which gives bright red eyes. The bw st double mutant has white eyes. A brown-eyed male was crossed to a scarlet- eyed female. The F1 progeny were wildtype. When the F1 males were test-crossed to bw/bw st/st females the following progeny phenotypes were produced: 1/4 wildtype, 1/4 brown, 1/4 scarlet, 1/4 white. These results show that the two genes are? Select all that apply a)linked and 25cM apart b)sex linked c)linked d)assorting independently Please answer asap and in short and content should not be palgarised please answer
Certain genes determine sex, fertility, and viability in Drosophila, and mutations in these genes affect the two sexes differently. Classify the descriptions below based on their occurrence in XY or XX flies. Some descriptions may be used in both categories. The expressed form of Dsx activates maleness genes and represses femaleness genes. XY XX Null mutations in the dsx gene result in an intersex phenotype. Loss-of-function mutations in the tra gene have no effect on phenotype. Sxl is expressed in early embryogenesis from the establishment promoter. Flies that produce Fru-M in brain cells from a transgene perform a mating dance and specifically court females. Loss-of-function mutations in the fru gene result in flies who court both males and females. Sxl regulates splicing of its own RNA to produce a functional protein. The expressed form of Dsx activates femaleness genes and represses maleness genes. Loss-of-function mutations in the Sxl gene have no effect on phenotype. Reset
Flies homozygous for recessive null mutations in thesevenless (sev) or bride-of-sevenless (boss) genes have the same mutant phenotype: Every ommatidium(facet) in their eyes lacks photoreceptor cell 7 (R7).The R7 cells enable flies to detect UV light.a. Given that flies normally move toward light, suggest a screening method that would enable you toidentify mutations in additional genes required forR7 determination.b. Would you be able to recover mutations in everygene required for R7 development with yourmethod? Explain.c. How could you tell whether any of the new mutationsyou found in your screen are alleles of sev or boss?d. Suppose you found one recessive mutant allele ofa gene not previously known to be involved in eyedevelopment. How could you use this allele in anew mutagenesis screen to find additional allelesof this gene? Why might you want additional mutant alleles to study the process?