BIOL207 Chapter Notes - Chapter 38: Allele Frequency, Population Genetics, Product Rule

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goldleopard391

24 Nov 2016

School

University of Alberta

Department

Biology (Biological Sciences)

Course

BIOL207

Professor

Kirst King- Jones

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The frequency of different alleles can be determined either from the frequency of. Knowing the frequency of alleles is important to determine disease risks and it can. 1st off in a simple population where we have 2 alleles at the same locus (a,a) we us the symbol p to represent the frequency of the dom allele in the population and q to represent the recessive allele. Since we only have the 2 possible alleles we can conclude that together the frequency of p and q together represents 100% of the alleles in a pop, in equation terms: (p + q = 1). To calculate these values in a representative sample we simply count the alleles and divide by the number of total individuals within the population. Remember homozygous either dominant (aa) or recessive (aa) will count for twice as much as a heterozygote (aa).

Related Questions

15. Population genetics provides answers for all of thefollowing questions except:

a. What is the frequency ofgenetic disease in a population?

b. What fraction of thephenotypic variation in a trait is the result of geneticvariation?

c. What alleles are most likelyto mutate?

d. Given certain quantifiablevariables, how long is a disease likely to persist?

e. How rapidly can a disease gaina foothold in a population?

16. Which of the following is not one of the assumptions of theHardy-Weinberg law?

a. The population is verylarge.

b. There is non-random matingwithin the population.

c. Mutations in the alleles donot occur.

d. No migration occurs into orout of the population.

e. The ability of all genotypesfor survival and reproduction is the same.

17. The heterozygote genotype frequency term for a gene with twoalternate alleles A (frequency p) and a (frequency q) in theHardy-Weinberg equation is:

a.p² b.q² c.2pq d.(p+q)² e. p+q

18. In humans, brachydactyly is a dominant condition. Sixthousand four hundred people in a population of 10,000 show thedisease (1,600 are BB, 4,800 are Bb) and 3,600 are normalphenotypes (bb). The frequency of the b allele is:

a.0.6 b.0.8 c.0.36 d..48 e. 0.16

19. Fitness is described as:

a. an individualâs ability tosurvive to adulthood

b. an individualâs ability toreproduce

c. an individualâs ability toadapt to change

d. all of the above are true

champagnewallaby382

I'm sorry for putting two questions on one request but I'mrunning out of uses for my subscription period. Please help!

1. Answer the following questions

(a âd) given the following information.

Please show your mathematical equations used and your work forfull credit, highlight your final answer:

Suppose we have one locus with two alleles with the followingabsolute viabilities

and initial allele frequencies.

Absolute viability:

AA = 0.95

AB = 0.95

BB = 0.65

Initial allele frequency:

Frequency A (p) = 0.2

Frequency of B (q) = 0.8

a. What are the relative fitnesses of the genotypes?

b. What is the average fitness in the population?

c. Assuming a general selection model what will the frequency ofboth alleles A and B be after one generation of selection?

d. What will the percent (%) change in the allele frequency of Abe after one generation of selection?

Will it be an increase or decrease change?

2. In wild Soay Sheep horn size is largely determined by asingle gene with two alleles. Let us assume for simplicity thatsheep with the dominant allele, H⁺, have large horns andsheep with recessive allele, H^s, have short horns. Belowis a table showing the relative reproductive success of individualswith the following genotypes. Assume relative reproductive successis our measure of relative fitness of genotypes.

Answer the following question (a-Âe).

Relative Reproductive Success:

H+H+ is 1

H+Hs is 1

HsHs is 0.60

a. What is the selection coefficient (s) value against therecessive allele (Hs)?

b. What type (mode) of selection is occurring at this locus ANDwhat is the relationship of the relative fitnesses of thegenotypes?

c. You want to model selection at this locus to determine therate at which the advantageous allele frequency will change afterselection. What is the proper equation to use to determine theallele (H+) frequency change after one generation of selection?

d. Assume before selection the initial allele frequencies areH+=0.1 and Hs=0.9. What will the change in H+ frequency be afterone generation of selection against the Hs allele? Show yourmathematical work and highlight your final answer.

e. Draw a predicted graph of the rate of change for H+AND Hs over say 600 generations. I am interested in if you can (a)label your axes correctly, (b) indicate the initial allelefrequencies correctly, and (c) show the predicted trendlines for the change in allele frequencies over generations.You should make one graph with two lines (one for H+ and one forHs). Label your lines as H+ and Hs, This eans you do notneed to perform any math to make your plots.)

burgundyyellowjacket390

Question:

Question 1: What is NOT a force of evolution?

Mutation of genes

Genetic drift

Equilibrium of populations

Migration of populations

Question 2:

Crossing true breeding dark-coated sheep with true breedinglight-coated sheep always results in 100% dark-coated offspring.You are screening a population of 300 Soay sheep for coat color,and you count 243 dark sheep and 57 light sheep. What is thegenotype frequency of the homozygous recessive sheep forTYRP1 gene if the population is in Hardy-Weinbergequilibrium?

.421

0..176

0.864

0.190

Question 3:

In the same population, if it is under Hardy-Weinbergequilibrium, how many individuals do you expect to be heterozygousat TYRP1?

217

0.492

148

124

Question 4:

Rabbit's ears can be either short (dominant) or floppy(recessive). If a population of rabbits in Hardy-Weinbergequilibrium has 250 short eared rabbits and 100 floppy earedrabbits, what is the allele frequency of the "short" allele?

.465

0.714

0.845

0.535

Question 5:

To calculate degrees of freedom, we use the following formula:Degrees of freedom - the number of constraints imposed on yourcomparison. How many constraints are there when we use theChi-square test for Hardy Weinberg equilibrium?

Question 6:

You perform a Chi-square test for gene X and find thep-value to be greater than 0.05. What can you say with 95%certainty about this population?

This population is in Hardy-Weinberg equilibrium at theX locus: gene X isinfluenced by at least oneforce of evolution.

This population is in Hardy-Weinberg equilibrium at theX locus: gene X is notinfluenced by any forces ofevolution.

This population is not in Hardy-Weinberg equilibrium at theX locus: gene X isinfluenced by at least oneforce of evolution.

This population is not in Hardy-Weinberg equilibrium at theX locus: gene X is notinfluenced by any forces ofevolution.

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BIOL207 Chapter Notes - Chapter 38: Allele Frequency, Population Genetics, Product Rule

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