Concept explainers
The frequency of tasters and nontasters of PTC (see Problem
a. Calculate the frequency of the dominant (T) allele for PTC tasting and the recessive (t) allele for nontasting in each population.
b. Assuming that Hardy
Want to see the full answer?
Check out a sample textbook solutionChapter 22 Solutions
GENETIC ANALYSIS: AN INTEG. APP. W/MAS
Additional Science Textbook Solutions
Laboratory Manual For Human Anatomy & Physiology
Anatomy & Physiology
Loose Leaf For Integrated Principles Of Zoology
Biology Illinois Edition (Glencoe Science)
- Cystic fibrosis (CF) is a recessive autosomal disorder. In certain populations of Northern European descent, the number of people born with this disorder is about 1 in 2500. Assuming Hardy- Weinberg equilibrium for this trait: A. What are the frequencies for the normal and CF alleles? B. What are the genotype frequencies of homozygous normal, heterozygous, and homozygous affected individuals? C. Assuming random mating, what is the probability that two phenotypically unaffected heterozygous carriers will choose each other as mates?arrow_forwardAssume that egg laying in hens is determined by a pair of alleles at each of two independently assorting loci that are additive in their effects. Hens with a HHLL genotype lays an average of 16 eggs a day, while hens with a hhll genotype lays an average of 4 eggs a day. Farmer John can choose between two hens to buy: Caroline (hhLl) or San Francisco (HhLl). Which hen should he buy to ensure that he gets the most eggs and how much eggs do you expect her to lay per day?arrow_forwardUsing the HardyWeinberg Law in Human Genetics Suppose you are monitoring the allelic and genotypic frequencies of the MN blood group locus (see Question 2 for a description of the MN blood group) in a small human population. You find that for 1-year-old children, the genotypic frequencies are MM = 0.25, MN = 0.5, and NN = 0.25, whereas the genotypic frequencies for adults are MM = 0.3, MN = 0.4, and NN = 0.3. a. Compute the M and N allele frequencies for 1-year-olds and adults. b. Are the allele frequencies in equilibrium in this population? c. Are the genotypic frequencies in equilibrium?arrow_forward
- Suppose that in unicorns, two autosomal loci interact to determine the type of tail. One locus controls whether a tail is present at all. The allele for a tail, T, is dominant over the allele for no tail, t. If a unicorn has a tail, then alleles with an unknown dominance relationship at a second locus determine whether the tail is curly or straight. Define the alleles for tail texture as U for a straight tail and U for a curly tail. S Farmer Baldridge has two unicorns with curly tails. When he crosses them, one-half of the progeny have curly tails, one-quarter have straight tails, and one-quarter do not have a tail. What are the genotypes of the parents at the tail-presence gene? TT X TT TT x tt Tt x Tt Tt x tt tt x tt What are the genotypes of the parents at the tail-texture gene? SC SC OU'U XU³UC сс OU'U' xU°U C C C C OU°UXU°Uº ƯU QU'U XU U C сс SS SS OUU³XU³U³ Place the unicorn genotype or genotypes below each unicorn phenotype in the pedigree. Some unicorn phenotypes may be the…arrow_forwardAndrogenetic alopecia (pattern baldness) is a complextrait in humans governed by several genes, but supposea human population exists in which a single autosomalallele determines pattern baldness. This allele is dominant in males and recessive in females. The population is in Hardy-Weinberg equilibrium, and 51% ofthe men are bald.a. What is the allele frequency of the baldness alleleamong males?b. What is the allele frequency of the baldness alleleamong females?c. What percentage of the women in this populationwill exhibit pattern baldness? d. Assuming random mating, what proportion of allmatings should be between a bald man and anonbald woman?e. What percentage of the bald men in the populationare heterozygotes?f. If a nonbald couple produces a bald son, what isthe probability that their next son will be bald?g. A woman with androgenetic alopecia has a daughter, but nothing is known about the father. What isthe probability that the daughter will be bald?arrow_forwardFor each of the following characteristics, indicate whether it would be considered a discontinuous characteristic or a quantitative characteristic. Briefly justify your answer. a. Kernel color in a strain of wheat, in which two codominant alleles segregating at a single locus determine the color. Thus, there are three phenotypes present in this strain: white, light red, and medium red. b. Body weight in a family of Labrador retrievers. An autosomal recessive allele that causes dwarfism is present in this family. Two phenotypes are recognized: dwarf (less than 13 kg) and normal (greater than 23 kg). c. Presence or absence of leprosy. Susceptibility to leprosy is determined by multiple genes and numerous environmental factors. d. Number of toes in guinea pigs, which is influenced by genes at many loci. e. Number of fingers in humans. Extra (more than five) fingers are caused by the presence of an autosomal dominant allele.arrow_forward
- Using the example of pea color in Mendel’s pea plants, can you devise equations to determine the allele frequencies of A and a from the genotype frequencies of aa, Aa, and AA?arrow_forwardConsider the following pedigree below for a rare autosomal trait. Be sure to take into account the inbreeding convention, when needed. 1. What is the probability that individual B is heterozygous? 2. What is the inbreeding coefficient of individual E? 3. After divorce, individual “A” decides to marry at random outside the pedigree. If the population allele frequency of the rare autosomal trait is 0.012, what are the chances of having an affected child for his first born of his second marriage?arrow_forwardThe Valyrian elders are doing projections about the future and want to calculate the frequencies of certain genotypes in the next generation. They are only interested in figuring out what proportion of the next generation will bear the signature Valyrian silver hair phenotype. (Assume the allele frequencies remain unchanged from the first part of this question.) A-What will the frequency of the AA genotype be? b-What will the frequency of the Aa genotype be?arrow_forward
- A mutant allele in persons with familial hypercholesterolemia (FH) causes death due to a lack of liver receptors for LDL. Susceptible persons have half the normal number of receptors, while other individuals have the normal number of receptors. In a phenotypically normal couple, the man had a female 1 cousin (on his father’s side) who died from FH; the woman had a maternal uncle with FH. a. Calculate the probability that neither of the couple might be susceptible. b. Calculate the probability that one of them might be susceptible, but the other is not. c. Calculate the probability that they will have an FH child if a test discloses that both of them are susceptible.arrow_forwardAssume that human ear length is influenced by multiple genetic and environmental factors. Suppose you measure ear length in three groups of people, in which group A consists of five unrelated people, group B consists of five siblings, and group C consists of five first cousins. a. With the assumption that the environments of all three groups are similar, which group should have the highest phenotypic variance? Explain why. b. Is it realistic to assume that the environmental variance for each group is similar? Explain your answer.arrow_forwardIn Figure 20-5, note that the difference in survival rates between AS and AA genotypes declines as children get older. Offer one possible explanation for this observationarrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning