Concept explainers
a.
To determine: The proportion of the following-
- Vulcan
phenotypes for all three characters.
Introduction. Proportion means the percentage. The proportion of the genotypes means the percentage or the part among the whole proportion of the genes given in the linkage map. The proportion can be found by using the D. Harrison formula.
b.
To determine: The proportion of the following-
- Earth phenotypes for all three characters.
Introduction. The frequency of parental must be calculated first. Crossing over occurs approx 15 between P and A, which means occur 85 percent is left. Crossing over occurs approx 20 percent between A and R, and hence 80 percent left.
c.
To determine: The proportion of the following-
- Vulcan ears and heart but Earth adrenals
Introduction: Crossing over occurs approx 15 between P and A, which means occur 85 percent is remaining. Crossing over occurs approx 20 percent between A and R, and hence 80 percent left.
d.
To determine: The proportion of the following-
- Vulcan ears but Earth heart and adrenals.
Introduction: To find Vulcan ears and hearts and Earth adrenals, a crossover must occur in both regions, producing double crossovers
Want to see the full answer?
Check out a sample textbook solutionChapter 4 Solutions
Introduction to Genetic Analysis
- 10 cM separates two hypothetical autosomal human genes. The dominant alleles are have complete penetrance and will result to Crossed eyes (e+) and short thumbs (th+). Four children are born to a normal guy and cross-eyed, small-thumbed woman. Two of the children have short thumbs and the other two have crossed eyes. She is carrying her fifth child. What is the probability that this fifth child will be cross-eyed and have short thumbs?arrow_forwardIn ogres, nose type results from a genetic maternal effect where the autosomal allele for a warty nose (w*) is dominant over the allele for a smooth nose (w). Shrek's third cousin once removed, Shrekina, has a warty nose with a w*w* genotype. She marries Golothm, a male, smooth nosed ogre with a ww genotype and they have a warty nosed daughter, Mary. Mary marries Blutto, a smooth nosed male with a ww genotype to produce a son and a daughter. What would be the expected genotypes and ratio of the F2 ogres (Mary and Blutto's children)? O 1 ww+ : 1 ww O 1 XwXw+ :1 XwXw O 1 ww: 2 w+w: 1 w+w+ O 1 ww+ : 1 w+w+ O 1 XwXw+ :1 YXw+arrow_forwardThere is an autosomal gene in cats that controls whether or not they also have white patches of fur (W = white spots, w= no white spots). Considering this along with the Orange gene (O0 and OB) from the previous question, and how it works, how many possible genotypes (using these 4 alleles) are there for cats that are orange, black, and white (in other words, calico)?arrow_forward
- Vulcans have pointed ears (determined by allele P), absent adrenals (determined by A), and a right-sided heart(determined by R). All these alleles are dominant to normal Earth alleles: rounded ears (p), present adrenals (a),and a left-sided heart (r). The three loci are autosomaland linked as shown in this linkage map:10 m.u. 25 m.u.P A RMr. Spock, first officer of the starship Enterprise, has aVulcan father and an Earthling mother. If Mr. Spock marries an Earth woman and there is no (genetic) interference, what proportion of their children will havea. Vulcan phenotypes for all three characters?b. Earth phenotypes for all three characters?c. Vulcan ears and heart but Earth adrenals?d. Vulcan ears but Earth heart and adrenals?arrow_forwardA recessive maternal effect mutant in zebrafish, called ichabod, results in embryos lacking heads that are non-viable. You have been instructed to identify females that are homozygous for the ichabod mutant allele. At your disposal are a tank of wild-type fish (males and females), a tank of male and female parental fish that are all heterozygous for the ichabod mutant allele (ichabod/+), and a tank of F1 fish derived from a cross between a heterozygous male and heterozygous female (ichabod/+). Which of the following would be a way to identify females that are homozygous mutant, i.e. ichabod/ichabod? Select all answers that would work.arrow_forwardA recessive maternal effect mutant in zebrafish, called ichabod, results in embryos lacking heads that are non-viable. You have been instructed to identify females that are homozygous for the ichabod mutant allele. At your disposal are a tank of wild-type fish (males and females), a tank of male and female parental fish that are all heterozygous for the ichabod mutant allele (ichabodl+), and a tank of F1 fish derived from a cross between a heterozygous male and heterozygous female (ichabodl+). Which of the following would be a way to identify females that are homozygous mutant, i.e. ichabodlichabod? Select all answers that would work. Cross F1 females to F1 males and observe their offspring. Crosses that produce headless offspring came from a homozygous female. a. Cross F1 males to females from the parental tank and observe their offspring. 25% of these crosses should produce headless offspring. b. Cross F1 females to F1 males to make the F2 generation. Cross F2 females to F2 males and…arrow_forward
- A standard three-point mapping is conducted for recessive mutations in autosomal genes purple eye (pr), curved wing ( c) and black body (b). Their wild type alleles are also used for genetic mapping. An F1 Drosophila female heterozygous for purple eye (pr), curved wing (c) and black (b) is crossed to a triply homozygous mutant male. The observed numbers and phenotypes of the offspring are as follows: 360 pr c b 380 pr+ c+ b+ 104 pr c+ b 96 pr+ c b+ 30 pr c b+ 20 pr+ c+ b 6 pr c+ b+ 4 pr+ c b PROVIDE THE FOLLOWING: A) State the order of genes on this chromosome. B) Calculate map distances between the gene pairs: pr-c, pr-b, c-b. Show calculations, state the number of map units and which gene pairs they refer to.arrow_forwardA woman who is heterozygous for gene B has brown eyes. B is a dominant allele for brown pigmentation, while b is recessive allele for blue pigmentation. The woman has a patch of blue color in her left eye. Give THREE (3) reasons how this might occur.arrow_forwardIn the snail Cepaea nemoralis, an autosomal allele causing a banded shell (BB) is recessive to the allele for an unbanded shell (BO). Genes at a different locus determine the background color of the shell; here, yellow (CY) is recessive to brown (CBw). A banded, yellow snail is crossed with a homozygous brown, unbanded snail. The F1 are then crossed with banded, yellow snails (a testcross). Q.What will the results of the testcross be if the loci assort independently?arrow_forward
- In the snail Cepaea nemoralis, an autosomal allele causing a banded shell (BB) is recessive to the allele for an unbanded shell (BO). Genes at a different locus determine the background color of the shell; here, yellow (CY) is recessive to brown (CBw). A banded, yellow snail is crossed with a homozygous brown, unbanded snail. The F1 are then crossed with banded, yellow snails (a testcross). a. What will the results of the testcross be if the loci that control banding and color are linked with no crossing over? b. What will the results of the testcross be if the loci assort independently? c. What will the results of the testcross be if the loci are linked and 20 m.u. apart?arrow_forwardIn the snail Cepaea nemoralis, an autosomal allele causing a banded shell (BB) is recessive to the allele for an unbanded shell (BO). Genes at a different locus determine the background color of the shell; here, yellow (CY) is recessive to brown (CBw). A banded, yellow snail is crossed with a homozygous brown, unbanded snail. The F1 are then crossed with banded, yellow snails (a testcross). Q.What will the results of the testcross be if the loci that control banding and color are linked with no crossing over?arrow_forwardAn ear of corn has a total of 381 grains, including 216 Purple & Smooth, 79 Purple & Shrunken, 65 Yellow & Smooth, and 21 Yellow & Shrunken. This ear of corn was produced by a dihybrid cross (PpSs x PpSs) involving two pairs of heterozygous genes resulting in a theoretical (expected) ratio of 9:3:3:1. Use a chi squarearrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning