To analyze:
The bicoid is characterized as a coordinate, maternal effect gene. Based on this, answer the following:
Determine the
Determine the phenotype of progeny produced from a cross between a female that is homozygous for a loss of function bicoid allele and a wild type male.
Provide an explanation on, if losses of bicoid function in the egg results in lethality during embryogenesis how are females homozygous for bicoid produced. Also determine phenotype of a male homozygous for bicoid loss of function alleles.
Introduction:
Bicoid is an example of a maternal effect gene. The phenotype result from maternal effect gene is identified by the mother genotype and not by the organism phenotype. This is because the egg receives protein and mRNA needed for proper development from the mother for the determination and development of a body axis in an organism. Bicoid is essential, thus, it is also termed as axis determination gene.
Want to see the full answer?
Check out a sample textbook solutionChapter 20 Solutions
Genetic Analysis: An Integrated Approach (2nd Edition)
- Please take a look at the attachment.arrow_forwardDeranged: is a phenotype in Drosophila in which the thoracic bristles are disarranged and the wings held vertically upward. Crosses between deranged females and normal males, each from pure stock cultures, result in a 1:1 ratio of normal females to deranged males among the progeny. What does this show? A. The gene for deranged is autosomal and dominant. B. The gene for deranged is autosomal and recessive. C. The gene for deranged is X-linked and dominant. D. The gene for deranged is X-linked and recessive. E. Deranged is determined by two genes interacting epistatically.arrow_forwardIn Drosophila, the wildtype eye color is black. In the laboratory, you screened for mutants than when homozygous results to different eye phenotypes. You found two mutants 1) red eye (re) and 2) white eye (we). You performed a complementation test and the resulting eye phenotype was gray. From the results, what conclusion can you make? A. There was complementation, thus the two mutations are alleles of different genes. B. There was no complementation, thus the two mutations are alleles of different genes. C. The two mutations failed to complement, thus they are alleles of different genes. D. The two mutations failed to complement, thus they are alleles of the same genes. E. The two mutations complemented, hence they are likely controlled by different genes.arrow_forward
- Imagine a scenario in which prenatal testing of a human female fetus indicates that the baby will have a normal XX karyotype but is heterozygous for a mutation that inactivates the Xist promoter. Allele “Xr” represents the mutated version of the Xist promoter, and “XR” represents the normal version of the Xist promoter. How will this mutation affect the process of X inactivation?A. "X inactivation will still be random with both mutant and normal X chromosomes being randomly inactivated" B. "The chromosome with the mutant Xist promoter will always be active" C. "The chromosome with the mutant Xist promoter will always be inactivated" D. "The normal X chromosome (no mutation in Xist) will always be active" E. "The normal X chromosome (no mutation in Xist) will always be inactivated"arrow_forwardThe 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…arrow_forwardIn Drosophila, the X-linked recessive mutation vermilion (v) causes bright red eyes, in contrast to the brick-red eyes of wild type. A separate autosomal recessive mutation, suppressor of vermilion (su-v), causes flies homozygous or hemizygous for v to have wildtype eyes. In the absence of vermilion alleles, su-v has no effect on eye color. Determine the F1 and F2 phenotypic ratios from a cross between a female with wild-type alleles at the vermilion locus, but who is homozygous for su-v, with a vermilion male who has wildtype alleles at the su-v locusarrow_forward
- 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…arrow_forwardDrosophila females heterozygous for three recessive mutations, a, b, and c , were crossed to males homozygous for all three mutations.The cross yielded the following results: in the image Q. Construct a linkage map showing the correct order of these genes and estimate the distances between them.arrow_forwardIt is assumed that in Drosophila the following genotypes produce phenotypes. َA- B- = Red color A- bb = Plum color aa B- = Magenta color aa bb = White color The third latent genotype, cc, kills homozygous Plums, but has no effect on other genotypes. Also, genotype C- does not produce a large phenotype. If first-generation Drosophilas are heterozygous for all of these genes and interbreed, what phenotypic ratios are expected in society?arrow_forward
- Please help and explainarrow_forwarda. What is the Raly gene? What does it encode? How does it relate to the lethality of Ay? b. A heterozygous mouse AAy does not produce enough pigment and it is yellow. Homozygous individuals die during development, but AAy heterozygous do not. Why? You may use any graphic aid to explain this, if necessary. This means that you may use a Punnett square or a forking segregation diagram, or computations with fractions. c. Explain why there is a non-Mendelian 2:1 yellow/agouti phenotypic ratio in this cross.arrow_forwardIf a Drosophila female that is homozygous for an X-linked recessive mutation is bred with a male that carries the corresponding wild- type allele, the offspring will show the mutant phenotype in all individuals. be uniform wild-type. show a phenotype intermediate to the parents' phenotype. show the mutant phenotype in all males and the wild-type phenotype in all females. have mutant and wild-type males and mutant and wild-type females.arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education