Exam 20: Genetic Analysis of Quantitative Traits

The pattern of species evolution known as ___________is one of branching in which an ancestral species gives rise to two or more new species.

Draw a pedigree for an inbreeding coefficient of F= 2(1/2)⁴.

Mexican hairless dogs are heterozygous (Hh), carrying a single copy of the lethal allele. In a given population, the Hh genotypic frequency is 60% and the frequency of each homozygote is 20%. Assuming w = 1 for the Hh and hh dogs, what is the estimated genotypic frequency of the lethal HH genotype after reproduction?

In an island population, the frequencies of the three MN blood types are given here: M: 550 MN: 725 N: 225 a. Calculate the allele frequency of M and N. b. Assuming random mating, what are the expected frequencies for each blood type? c. Use chi- square analysis to test your hypothesis that mating is random for this population.

Physical separation of a segment of a large population by a physical barrier that prevents gene flow can lead to___________ .

Both the founder effect and the bottleneck effect are mechanisms that produce large allele frequency sampling errors in a small population due to__________ .

The incidence of Tay- Sachs, an autosomal recessive genetic disorder, is approximately 1 in 3,500 in a certain population of Ashkenazi Jews. Assuming that this population is in Hardy- Weinberg equilibrium, what is the probability that a phenotypically normal female, with no family history, and a phenotypically normal male, who had an affected sister, will have a child with Tay- Sachs?

In a group of 500 people, the frequency of genotype NN is 40%. Assuming both autosomal inheritance and that the population is in Hardy- Weinberg equilibrium, how many individuals would you expect to have the MN genotype?

What type of statistical analysis is used to compare observed and expected results in order to evaluate the validity of an estimate based on the Hardy- Weinberg equilibrium?

What is the consequence of natural selection favoring the heterozygous genotype (as exhibited by the sickle cell allele in malaria- prone regions), in which alleles reach stable equilibrium frequencies that are maintained by the ongoing action of selection against the homozygous genotypes?

What is a common type of nonrandom mating?

What are the three key elements for determining F, a measure that a particular allele is IBD, using pedigree analysis?

Using the allele frequencies in the table below, what is the probability that a random person would be heterozygous 12/14 for VAW? $\text { Allele Frequencies for Three STRP Loci Used in CODIS }$ D8531S3 VAW FAG Allele Frequency Allele Frequency Allele Frequency 12 0.015 12 0.015 18 0.015 13 0.015 14 0.131 19 0.061 14 0.134 15 0.119 20 0.125 15 0.270 16 0.186 21 0.180 16 0.229 17 0.257 22 0.209 17 0.162 19 0.189 23 0.131 18 0.162 0.015 0.088 24 0.146 19 0.015 25 0.094 26 0.018

Using the allele frequencies in the table below, what is the probability that a random person is heterozygous 12/14 for VAW and homozygous 18/18 for FAG? (Assume that the two loci are unlinked.) $\text { Allele Frequencies for Three STRP Loci Used in CODIS }$ D8531S3 VAW FAG Allele Frequency Allele Frequency Allele Frequency 12 0.015 12 0.015 18 0.015 13 0.015 14 0.131 19 0.061 14 0.134 15 0.119 20 0.125 15 0.270 16 0.186 21 0.180 16 0.229 17 0.257 22 0.209 17 0.162 19 0.189 23 0.131 18 0.162 0.015 0.088 24 0.146 19 0.015 25 0.094 26 0.018

Cheetahs exhibit significant inbreeding and loss of heterozygosity due to overhunting and loss of habitat experienced at some point in their evolutionary history. Which genetic mechanism occurs when a large population is substantially reduced at random, acting independently of natural selection?

Jeffrey Pines from Mt. Rose were genotyped at a resistance gene for a type of fungi that affects pines. Genotypes of 1000 of these Jeffrey Pines were: 300 R1R1, 500 R1R2, and 200 R2R2. Use a chi- square (χ2) test to determine if this population is in Hardy- Weinberg equilibrium? The critical chi- square value at P=.05 for 1 degree of freedom is 3.84.

Inbreeding depression, the reduction in fitness of inbred organisms, often results from the reduced level of what (within the gene pool)?

Burkitt's lymphoma is a cancer of the lymphatic system that is more common in individuals who are homozygous þAþA that succumb more easily to malaria. þSþS individuals suffer from anemia. þAþS have the highest relative fitness. Resistance to malaria and Burkitt's lymphoma are both an example of __________advantage.

In the general population, 1 in 300 individuals is a carrier for Tay- Sachs disease, while 1 in 30 individuals of Ashkenazi Jew descent are carriers. Tay- Sachs also affects 1 in 30 individuals with French- Canadian ancestry, although two completely unique mutations are responsible for the Ashkenazi and French- Canadian mutations. What are the chances of two individuals who are carriers having a child with Tay- Sachs if a. both individuals are not of Ashkenazi or French- Canadian descent? b. one individual is of Ashkenazi descent and the other is from the general population? c. both individuals are of Ashkenazi descent?

You are studying ABO blood groups, and know that 6.25% of the population has genotype I^AI^A and 42.25% of the population has Type O blood. What is the expected frequency of blood type B?