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 (2nd Edition)
- + ec +/Y + + w/Y y ec +/Y + ec +/y ec w ++ w/y ec w у ес +у ес и Determine the order in which the three loci y, ec, and w Occur on the chromosome and prepare a linkage map. 7.22 A cross involving X-linked genes was made between yellow, bar, vermilion female fies and wild males, and the F1 females were crossed with y B v males. The following phenotypes were obtained when 1000 progeny were exam- ined: Dra ord ma the 7.2 546 244 160 50 + + + + Bv y Bv y+ + y+v y B+ and an and and and +B + re + + v ge Determine the order in which the three loci occur on the chromosome and prepare a linkage map. 7.23 Female Drosophila heterozygous for ebony (e"le), scarlet (st*/st), and spineless (ss*/ss) were testcrossed, and the following progeny were obtained: PROGENCY PHENOTYPES NUMBER ir Wild type Ebony Ebony, scarlet Ebony, spineless Ebony, scarlet, spineless Scarlet 67 8. 68 347 78 368 Scarlet, spineless Spineless (a) Are these genes linked? Justify your answer. (b) Write the genes given on a…arrow_forwardIn 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_forward
- 10) 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_forwardIn 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_forward
- b) You test cross an F1 fish (with genotype BbCc) and obtain 1000 offsprings in F2 generation with the following results: 474 Bbcc, 480 bbCc, 20 BbCc and 26 bbcc.1. Create and fill in a Punnet square for this cross.2. What type of cross is it? 3. Are these loci linked? 4. What are the two parental classes and the two recombinant classes of offspring? 5. What is the percentage of recombination between these two loci? Show your calculations. 6. How many map units apart are they?arrow_forwardIn corn, male sterility is controlled by maternal cytoplasmic elements. This phenotype renders the male part of the corn plants (i.e the tassel) unable to produce fertile pollen; the female parts, however, remain receptive to pollination by pollen from male fertile corn plants. However, the presence of a nuclear fertility restorer gene F restores fertility to male sterile lines Using the cardboard chips, simulate the crosses indicated below. Give the genotypes and phenotypes of the offsprings in each cross, and properly label the nucleus and the cytoplasm of each individual in the cross Legend male sterile cytoplasm Male fertile cytoplasm FF nucleus Ff nucleus ff nucleus A. Male sterile female x FF male Explain the phenotype of the offspring B. Male sterile female x Ff male Explain the phenotype of the offspringarrow_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
- Consider 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_forwardThe answer is "D" but can you explain in a short summary why D is the answer pleasearrow_forwardShort hair (S) in rabbits is dominant over long hair (s). The following crosses are carried out, producing the progeny shown. Give all possible genotypes of the parents in each cross. The Remaining subparts to be solve is Letter D and E.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