IN DROSOPHILA, AN X-LINKED RECESSIVE MUTATION, Xm CAUSES MINIATURE WINGS. LIST THE F₂ PHENOTYPIC RATIOS IF: • A MINIATURE-WINGED FEMALE IS CROSSED WITH A NORMAL MALE AND • A MINIATURE-WINGED MALE IS CROSSED WITH A NORMAL FEMALE. • WHAT WOULD THE PHENOTYPIC RATIO FROM (A) BE IF THE MINIATURE- WINGED GENE WERE AUTOSOMAL? ASSUME IN ALL CASES THAT THE P1 INDIVIDUALS ARE TRUE-BREEDING.

IN DROSOPHILA, AN X-LINKED RECESSIVE MUTATION, Xm CAUSES MINIATURE WINGS. LIST THE F₂ PHENOTYPIC RATIOS IF: • A MINIATURE-WINGED FEMALE IS CROSSED WITH A NORMAL MALE AND • A MINIATURE-WINGED MALE IS CROSSED WITH A NORMAL FEMALE. • WHAT WOULD THE PHENOTYPIC RATIO FROM (A) BE IF THE MINIATURE- WINGED GENE WERE AUTOSOMAL? ASSUME IN ALL CASES THAT THE P1 INDIVIDUALS ARE TRUE-BREEDING.

Name: IN DROSOPHILA, AN X-LINKEDRECESSIVE MUTATION, Xm CAUSESMINIATURE WING
Uploaded: 2024-03-20T06:42:55.000Z
Channel: Bartleby
Description: IN DROSOPHILA, AN X-LINKEDRECESSIVE MUTATION, Xm CAUSESMINIATURE WINGS. LISTTHE F₂ PHENOTYPIC RATIOS IF:A MINIATURE-WINGED FEMALE ISCROSSED WITH A NORMAL MALE ANDA MINIATURE-WINGED MALE IS●●CROSSED WITH A NORMAL FEMALE.WHAT WOULD THE PHENOTYPIC RATI

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 16QP: Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior...

See similar textbooks

Similar questions

A Drosophila male is heterozygous for a reciprocaltranslocation between an autosome and the Y chromosome. The part of the autosome now present onthe Y chromosome contains the dominant mutationLyra (shortened wings); the other (normal) copyof the same autosome is Lyra+. This male is nowmated with a true-breeding, wild-type female. Whatkinds of progeny would be obtained, and in whatproportions?
In Drosophila, a cross (cross 1) was made between twomutant flies, one homozygous for the recessive mutationbent wing (b) and the other homozygous for the recessivemutation eyeless (e). The mutations e and b are alleles oftwo different genes that are known to be very closelylinked on the tiny autosomal chromosome 4. All the progeny had a wild-type phenotype. One of the female progeny was crossed with a male of genotype b e/b e ; we willcall this cross 2. Most of the progeny of cross 2 were of theexpected types, but there was also one rare female ofwild-type phenotype.a. Explain what the common progeny are expected tobe from cross 2.b. Could the rare wild-type female have arisen by (1)crossing over or (2) nondisjunction? Explain.
In Drosophila, a heterozygous female for the X-linkedrecessive traits a, b, and c was crossed to a male that phenotypically expressed a, b, and c. The offspring occurred inthe following phenotypic ratios.+ b c 460a + + 450a b c 32+ + + 38a + c 11+ b + 9 No other phenotypes were observed.(a) What progeny phenotypes are missing? Why?
In Drosophila, a heterozygous female for the X-linkedrecessive traits a, b, and c was crossed to a male that phenotypically expressed a, b, and c. The offspring occurred inthe following phenotypic ratios.+ b c 460a + + 450a b c 32+ + + 38a + c 11+ b + 9 No other phenotypes were observed.(a) What is the genotypic arrangement of the alleles ofthese genes on the X chromosome of the female?
In a cross in Drosophila involving the X-linked recessive eye mutationwhite and the autosomally linked recessive eye mutation sepia(resulting in a dark eye), predict the F1 and F2 results of crossingtrue-breeding parents of the following phenotypes:(a) white females * sepia males(b) sepia females * white malesNote that white is epistatic to the expression of sepia
The Drosophila gene Sex lethal (Sxl) is deserving of itsname. Certain alleles have no effect on XY animals butcause XX animals to die early in development. Other alleles have no effect on XX animals but cause XY animals to die early in development. Thus, some Sxl allelesare lethal to females, while others are lethal to males.a. Would you expect a null mutation in Sxl to causelethality in males or in females? b. Why do Sxl alleles of either type cause lethality ina specific sex?The gene transformer (tra) gets its name from sexualtransformation, as some tra alleles can change XXanimals into morphological males, while other traalleles can change XY animals into morphologicalfemales.c. Which of these sex transformations would becaused by null alleles of tra and which would becaused by constitutively active alleles of tra?d. In contrast with Sxl, null tra mutations do notcause lethality either in XX or in XY animals.However, the Sxl protein regulates the productionof the Tra protein. Why…
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
In Drosophila, the gene loci for curved wings and purple eyes are 20 centimorgans (map units) apart from each other on an autosomal chromosome. Wild-type flies were mated with double mutant flies with cv cv p p genotypes and curved wing/purple eye phenotypes. AlIl of the F1 flies had wild type phenotypes. The F, flies were crossed with double mutant flies with cv cv p'p genotypes and curved wing/purple eye phenotypes. What are the predicted percentages of flies in the F2 generation with wild type wings and eyes, curved wings and wild type eyes, wild type wings and purple eyes, and curved wings and purple eyes?
In Drosophila, a heterozygous female for the X-linkedrecessive traits a, b, and c was crossed to a male that phenotypically expressed a, b, and c. The offspring occurred inthe following phenotypic ratios.+ b c 460a + + 450a b c 32+ + + 38a + c 11+ b + 9 No other phenotypes were observed.(a) Determine the correct sequence and construct amap of these genes on the X chromosome ?
A Drosophila embryo dies during early embryogenesis due to arecessive maternal effect allele called bicoid−. The wild-type alleleis designated bicoid+. What are the genotypes and phenotypes ofthe embryo’s mother and maternal grandparents?
The maternal-effect mutation bicoid (bcd) is recessive. Inthe absence of the bicoid protein product, embryogenesis isnot completed. Consider a cross between a female heterozygousfor the bicoid mutation (bcd+/ bcd-) and a homozygousmale(bcd-/ bcd-). How is it possible for a male homozygous for the mutationto exist?
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?