Concept explainers
Genes A, B, C, D, and E are linked on a chromosomeand occur in the order given. The test cross
a. If
b. Previous genetic linkage crosses have determined that recombination frequencies for these genes are
Want to see the full answer?
Check out a sample textbook solutionChapter 5 Solutions
Genetic Analysis: An Integrated Approach (3rd Edition)
- In com, male sterility is controlled by maternal cytoplasmic elements. However, the presence of a nuclear fertility restorer gene (F_) restores fertility to male sterile lines. a. What are the crosses male sterile female x FF male? Give the genotypes and phenotypes of the offspring in each cross. Explain.arrow_forwardDeduce the phenotypic proportions in the progeny of thefollowing crosses of autotetraploids in which the a+/a locus is very close to the centromere. (Assume that the fourhomologous chromosomes of any one type pair randomly two by two and that only one copy of the a+ allele isnecessary for the wild-type phenotype.)a. a+/a+/a/a × a/a/a /ab. a+/a/a /a × a/a/a/ac. a+/a/a /a × a+/a/a /ad. a+/a+/a /a × a+/a/a /aarrow_forward10) Two pure-breeding phlox plants were crossed, one with dark-blue flowers and the other with pinl The Fi generation all had dark-blue flowers. When the F₁ were crossed with each other, the F₂ generati consisted of 176 plants: 101 with dark-blue flowers, 33 with light-blue flowers, 30 with red flowers, ar pink flowers. 10) What progeny types would result from crossing pure-breeding plants with light-blue flowen breeding plants with red flowers? A) all would be dark blue B) 1 light blue: 1 red C) 9 dark blue: 3 light blue: 3 red: 1 pink D) all would be redarrow_forward
- In a fungus with four ascospores, a mutant allele lys-5causes the ascospores bearing that allele to be white,whereas the wild-type allele lys-5+ results in black ascospores. (Ascospores are the spores that constitute thefour products of meiosis.) Draw an ascus from each ofthe following crosses:a. lys-5 × lys-5+b. lys-5 × lys-5c. lys-5+ × lys-5+arrow_forwardIn autotetraploid Chinese primrose (Primula sinensis L.), the gene controlling stigma color is very near the centromere of the chromosome carrying it. The allele G for green stigma is dominant to g for red stigmas. A homozygous green autotetraploid strain is crossed with a homozygous red autotetraploid strain. Each of the F1 GGgg plants would obtain 12 gametes which are 2GG, 8Gg, and 2g. How were these obtained?arrow_forwardshows the results of a dihybrid cross involving seed shape and seed color. a. What proportion of the round and yellow F2 progeny from this cross is homozygous at both loci? b. What proportion of the round and yellow F2 progeny from this cross is homozygous at least at one locus?arrow_forward
- In fruit flies, red eyes (pr+_) are dominant to purple eyes (prpr) and normal wings (vg+_) are dominant to vestigial wings (vgvg). The genes are located on the same chromosome. A purebreeding red-eyed fly with vestigial wings was crossed with a pure-breeding purple-eyed fly with normal wings. All of the F1 progeny had a WT phenotype. The recombination frequency between the two genes is 15%. If an F1 individual was test crossed, what percentage of the progeny would you expect to have the WT phenotypearrow_forwardConsider the following Test Cross results & chromosome map: Test Cross Progeny 525 A B C 500 A+ B+C+ 456 A+ B C 308 A B+C+ 101 A B C+ 100 A+ B+C 2 A+ B C+ 1 A B+C Total Progeny = 1993 1-Based on the above data calculate the expectednumber of Double crossovers (DCOs)? Round answers to the closest whole number.arrow_forwardTo test for gene linkage a dihybrid testcross of A/a;B/b x a/a;b/b is carried out resulting in 100 progeny with the following phenotypes: AB - 30 Ab-22 a B - 20 ab - 28 Your null hypothesis is that genes A and B assort independently and are not linked. How many offspring would you expect to see with the A B phenotype? To test the null hypothesis that genes A and B are unlinked, you perform an exhaustive set of calculations and arrive at a chi-square value of 2.72. Based on the table below, do you accept or reject your null hypothesis with 95% confidence? Table 1: Critical values of the chi-square distribution with df degrees of freedom. 0.5 0.02 0.01 0.1 0.05 2.706 3.841 0.455 5.412 6.635 4.605 5.991 7.824 9.21 1.386 2.366 6.251 7.815 9.837 11.345 3.357 7.779 9.488 11.668 13.277 df 1 2 3 4 Write "accept" or "reject" in the blank. Given the expected phenotype probability that you determined above, what is the minimum number of offspring required to give a 95% chance of obtaining an…arrow_forward
- Calculate the map distances among the genes.arrow_forwardConsider the following Test Cross results & chromosome map: Test Cross Progeny 525 A B C 500 A+ B+C+ 456 A+ B C 308 A B+C+ 101 A B C+ 100 A+ B+C 2 A+ B C+ 1 A B+C Total Progeny = 1993 1-Calculate the interference.?arrow_forwardThree autosomal genes are linked along the same chromosome.The distance between gene A and B is 7 mu, the distance betweenB and C is 11 mu, and the distance between A and C is 4 mu. Anindividual that is AA bb CC was crossed to an individual that is aaBB cc to produce heterozygous F1 offspring. The F1 offspring werethen crossed to homozygous aa bb cc individuals to produce F2offspring.If we assume that no double crossovers occur, what percentageof F2 offspring is likely to be homozygous for all three genes?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