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Assume that genes, A and B are on the same chromosome and are 50 map units apart. An animal heterozygous at both loci is crosscd with one that is homozygous recessive at both loci. What percentage of the offspring will show recombinant
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- Let us suppose that two long-winged flies were crossed and that 77 long-winged and 24 short-winged specimens were counted in the offspring. a. Will the short-winged character be dominant or recessive?B. What will the genotypes of the parents be?C. What is the observed genotype ratio?arrow_forwardTwo organisms, AABBCCDDEE and aabbccddee, are mated to produce an F1 that is self-fertilized. If the capital letters represent dominant, independently assorting alleles: (a) how many different genotypes will occur in the F2? 3^5=243(AaBbCcDdEe) (b) what proportion of the F2 genotypes will be recessive for all five loci? (c) would you change your answers (a and/or b) if the initial cross occurred between AAbbCCddee X aaBBccDDEE parents? (d) would you change your answers (a and/or b) if the initial cross occurred between AABBCCDDEE X aabbccddEE parents?arrow_forwardErminette fowls have mostly light colored feathers with an occasional black one, giving a flecked appearance. A cross of two erminettes produced a total of 48 progeny, consisting of 22 erminettes, 14 blacks and 12 pure whites. What genetic basis of the erminette pattern is suggested? How would you test your hypotheses?arrow_forward
- a. If 3 completely dominant gene pairs A a, B b, C c are assorting independently,how many progeny genotypes are expected in a heterozygote? b. If 3 completely dominant gene pairs A a, B b, C c are assorting independently,what is the probability of obtaining an AbC gamete from an AaBbCcindividual?Express answer in fraction form.arrow_forwardTwo genes, designated A and B, are located 10 mu from each other.A third gene, designated C, is located 15 mu from B and 5 mufrom A. The parental generation consisting of AA bb CC and aaBB cc individuals were crossed to each other. The F1 heterozygoteswere then testcrossed to aa bb cc individuals. If we assume nodouble crossovers occur, what percentage of offspring would youexpect with the following genotypes?A. Aa Bb CcB. aa Bb CcC. Aa bb ccarrow_forwardTwo pure-breeding strains of flies are mated, and the F1 are intercrossed. The first strain has curled wings and black bodies. The second strain has straight wings and brown bodies. The F2 progeny are 271 straight wings with brown bodies, 31 curled wings with black bodies, 94 curled wings with brown bodies and 90 straight wings with black bodies. If instead of the above, assume the wing shape gene and the body color gene are completely linked. From parents that are curled winged with brown bodies mated to straight winged with black bodies, what would be the outcome of an F1 intercross? (Specify the phenotypes and the frequency of each expected).arrow_forward
- In snapdragons, heterozygotes for one of the genes have pink flowers, whereas homozygotes have red (R) or white (r) flowers. When plants with red flowers are crossed with plants with white flowers, what proportion/probability of the offspring will have pink flowers? Create a Punnett square.arrow_forwardConsider these two crosses and assume that independent segregation is exhibited by all gene pairs: RrmmTT x RRMmTtFfGg x FfGg Derive the gametic ratio of the second parent in each cross using the branching method. What proportion of the offspring in each cross will be heterozygous for all gene pairs? Derive the genotypic ratio for the offspring from each cross using the branching method. Show complete solutions.arrow_forwardIn snapdragons, red flower color (R) is incompletely dominant over white flower color (r), so that the heterozygote has pink flowers. A red snapdragon is crossed with a white snapdragon, and the F1 are intercrossed to produce F2. What is the genotype and phenotypes of the F1 and F2, along with their expected proportions? If the F1 are backcrossed to the white parent, what will be the expected genotype and phenotype of the offspring? If the F1 are backcrossed to the red parent and the resulting progeny are intercrossed, what is the expected proportions of genotypes and phenotypes in the progeny?arrow_forward
- For a certain chromosomal region, the mean number of crossovers at meiosis is calculated to be two per meiosis. In that region, what proportion of meioses are predicted to have (a) no crossovers? (b) one crossover? (c) two crossovers?arrow_forwardIn corn plants, a dominant allele Z inhibits kernel color, while the recessive allele z permits color when homozygous. At a different locus, the dominant allele X causes purple kernel color, while the homozygous recessive genotype causes red kernel color. If corn plants heterozygous for both the Z and X genes are crossed, what are the chances that the offspring will have purple kernels? Enter your answer as a decimal fraction in the box (e.g. 0.25).arrow_forwardTwo genes, A and B, are 10 map units apart along the same chromosome. A cross was made between AAbb and aaBB individuals to produce AaBb F1 offspring. The F1 offspring were then crossed to aabb individuals to yield an F2 generation. What would be the genotype(s) of F2 offspring that carry recombinant chromosomes? (Note: recombinant chromosomes are the product of crossing over). What percentage of F2 offspring would be Aabb?arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning