Concept explainers
Epidemiologic data on the population in the previous problem reveal that before the application of modern medical treatment, natural selection played a major role in shaping the frequencies of alleles. Heterozygous individuals have the highest relative fitness, and in comparison to heterozygotes, those who are
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Genetic Analysis: An Integrated Approach (3rd Edition)
- A hypothetical population of 10,000 humans has 6848 individuals with the blood type AA, 2846 individuals with blood type AB, and 306 individuals with the blood type BB. What is the frequency of each genotype in this population? What is the frequency of the A allele? What is the frequency of the B allele? If the next generation contained 25,000 individuals, how many individuals would have blood type BB, assuming the population is in Hardy-Weinberg equilibrium?arrow_forwardA sample of 100 individuals from a population that is dimorphic at the A locus has genotype counts as follows. AA: 30 Aa: 60 aa: 10 a) What are the allele frequencies in the population? b) What are the expected genotype frequencies, if the population were at HardyWeinberg equilibrium? c) Is the proportion of heterozygotes lower or higher than expected at Hardy-Weinberg equilibrium? What deviations from the assumptions of the model would best explain the observed difference?arrow_forwardAssume that the frequency of gene B in a hypothetical population Is 0.63, that there are only two alleles (B and b) of the gee in the population, that allele B is dominant over allele b, that neither allele has a selective advantage over the other, and that the population is at equilibrium with regard to this particular gene. What proportion of the population is expected to have the phenotype specified by the B allele according to the Hardy-Weinberg formula? 0.47 0.87 0.67 0.40 0.37arrow_forward
- Suppose the frequency of the recessive allele a for the recessive condition albinism is 0.2 Assume the Hardy-Weinberg distribution. What is the frequency of albinism in the general population? What fraction of the population are carriers?arrow_forwardIn a large herd of 5468 sheep, 76 animals have yellow fat, and the rest of the members of the herd have white fat. Yellow fat is inherited as a recessive trait. This herd is assumed to be in Hardy-Weinberg equilibrium. A. What are the frequencies of the white and yellow fat alleles in this population? B. Approximately how many sheep with white fat are heterozygous carriers of the yellow allele?arrow_forwardIn a donor population, the allele frequencies for the normal (HbA) and sickle-cell alleles (HbS) are 0.9 and 0.1 respectively. A group of 550 individuals migrates to a new population containing 10,000 individuals; in the recipient population, the allele frequencies are HbA = 0.99 and HbS =0.01. What will be the genotype frequencies of the conglomerate population in the next generation, assuming it achieves Hardy-Weinberg equilibrium in one generation?arrow_forward
- a.)If the frequency of an allele at a locus of interest is 0.57, what is the frequency of the genotype that is homozygous for this allele (that is, that genotype has two copies of this allele)? b.) If we know that the frequency of an allele at a locus of interest is 0.57, we have enough information to calculate the frequency of the related phenotypes in the population, assuming there are only two alleles.arrow_forwardThe frequency of individuals who express a recessive disease in a population is 16%. What variable in the Hardy Weinberg equations does the 16% refer to? Why?arrow_forwardIn monkeys, black coat color (B) is dominant over brown color (b). A population of monkeys was found to be composed of 67 brown coated individuals and 119 black coated individuals. What is the frequency of the b allele in this population? What is the frequency of the B allele in this population? Based upon the Hardy‑Weinberg formula, what proportion of the population is expected to have the genotype BB? Based upon the Hardy‑Weinberg formula, what proportion of the population is expected to bave black coat color? Based upon the Hardy‑Weinberg formula, how many individuals in this population would be expected to have the genotype Bb?arrow_forward
- In a large, randomly mating population with no appreciable forces working to change gene frequencies, the frequency of homozygous recessive individuals for the characteristic of extra-long eyelashes is 60 per 1000. What percent of this population carries this very desirable trait but displays the dominant phenotype of short eyelashes?arrow_forwardIf a population is in Hardy-Weinberg equilibrium for the multiple alleles A+, A and a, whose frequencies are p= 0.60 for A+, q= 0.20 for A, and r = 0.20 for a, what percentage of the population is expected to be heterozygous?arrow_forwardThe ability to taste the compound PTC is controlled by a dominant allele T, while individuals homozygous for the recessive allele (t) cannot taste PTC. In a population consisting of 500 individuals, 347 are tasters and 153 are non-PTC tasters. Calculate the frequency of the T and t alleles in this population, and frequency of the genotypes. (Please train yourself to use the Hardy-Weinberg equation.) To present your answers, follow the format in the picture below.arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning