Concept explainers
Mitotic recombination can occasionally produce a twin spot. Let’s suppose an animal species is heterozygous for two genes that govern fur color and length: one gene affects pigmentation, with dark pigmentation (A) dominant to albino (a); the other gene affects hair length, with long hair (L) dominant to short hair (l). The two genes are linked on the same chromosome. Let’s assume an animal of this species is
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
Genetics: Analysis and Principles
- For this particular family, what is the recombination rate between the D17S74 marker and the breast cancer gene? Lets say that at age 45 the third granddaughter III-3, is diagnosed with breast cancer. Now recalculate the recombination rate between the marker locus D17S74 and the breast cancer gene? Use only the 5 women in your analysis:the two daugthers in generation II and the three granddaughters in generation IIarrow_forwardThe mutant genes for vestigial wings and singed bristles are approximately 30 map units apart on chromosome II in Drosophila. Assume that a vestigial-winged female was mated to a singed-bristle male, and that the resulting F1 phenotypically wild type females were mated to vestigial singed males. Of 1000 offspring, which phenotype class would represent the product of crossing over between the genes, and how many would you expect? a) vestigial, 300 flies b) vestigial, 150 flies wild type, 300 flies d) singed, 150 flies e) vestigial, singed double mutants, 150 fliesarrow_forwardHemophilia and color blindness are both recessive conditions caused by genes on the X chromosome . To calculate the recombination frequency between the two genes, you draw a large number of pedigrees that include grandfathers with both hemophilia and color blindness , their daughters (who presumably have one chromosome with two normal alleles and one chromosome with two mutant alleles), and the daughters’ sons. Analyzing all the pedigrees together shows that 25 grandsons have both color blindness and hemophilia 24 have neither of the traits , 1 has color blindness only and 1 has hemophilia only . how many centimorgans seperate the hemophilia locus from the locus of the color blindness.arrow_forward
- Suppose that you are tending a mouse colony at a genetic research institute, and one day you discover a mouse with twisted ears. You breed this mouse with twisted ears and find that the trait is inherited. Both male and female mice may have twisted ears, but when you cross a twisted-eared male with a normal-eared female, you obtain results that differ from those obtained when you cross a twisted-eared female with a normal-eared male: the reciprocal crosses give different results. Describe how you would determine whether this trait results from a sexlinked gene, a sex-influenced gene, genetic maternal effect, a cytoplasmically inherited gene, or genomic imprinting. What crosses would you conduct, and what results would be expected with these different types of inheritance?arrow_forwardConsider two loci A and B that are 30 cM apart on chromosome 1 in the fruit fly. A paracentric inversion is found to span about half of the distance between these loci, but not include either A or B. What is the approximate recombination frequency expected for these loci in … flies that are heterozygous for this inversion? RF(A-B) for heterozygous flies is … flies that are homozygous for this inversion? RF(A-B) for homozygous flies is …arrow_forwardThree autosomal recessive mutations in yeast, all producing the same phenotype (m1, m2, and m3), are subjected to complementation analysis. Of the results shown below, which, if any, are alleles of one another? Predict the results of the cross that is not shown—that is, m2 * m3. Cross 1: m1 * m24 F1: all wild-type progeny Cross 2: m1 * m34 F1: all mutant progenyarrow_forward
- Explain the following: a- No parental type is produced during gametogenesis? b- A dominant wild type produced a sign spot in Drosophila? c- 9:7 phenotypic ratio is produced in dihybrid cross? d- 50% parental type gametes were produced during gametogenesis? e- All recombinant gametes were produced during gametogenesis?arrow_forwardTo determine the recombination frequency between body color and wing genes in flies, you perform several crosses where you cross an F1 having red body and smooth wings with a yellow-bodied, crinkle-winged fly. You get the following results. What is the distance between the genes for body color and wing surface in map units?arrow_forwardWhat is mitotic recombination? A heterozygous individual (Bb)with brown eyes has one eye with a small patch of blue. Providetwo or more explanations for how the blue patch may have occurred?arrow_forward
- You design Drosophila crosses to provide recombinationdata for gene a, which is located on the chromosome shownin Figure 15.12. Gene a has recombination frequencies of14% with the vestigial wing locus and 26% with the browneye locus. Approximately where is a located along thechromosome?arrow_forwardCould you have generated a chromosome map from the F2 progeny in cross 1 (assuming you crossed F1 males and females to each other to generate the F2)? What is the advantage of using cross 2 instead?arrow_forwardIn the accompanying pedigree, the vertical lines stand for protan color blindness, and the horizontal lines stand for deutan color blindness. These are separate conditions causing different misperceptions of colors; each is determined by a separate gene.a. Does the pedigree show any evidence that the genes are linked? b. If there is linkage, does the pedigree show any evidence of crossing over? Explain your answers to parts a and b with the aid of the diagram. c. Can you calculate a value for the recombination between these genes? Is this recombination by independent assortment or by crossing over?(picture added)arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage LearningHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning