1) In a survey of a population of a certain species of field rodent, the followi
ID: 186236 • Letter: 1
Question
1) In a survey of a population of a certain species of field rodent, the following data was collected: Black hair (genotype B,B) 18 - Brown hair (genotype B,B)-62 Yellow hair (genotype B,B,)-34 What are the frequencies of the two alleles? Is this population in a Hardy-Weinberg equilibrium? Test your hypothesis with a X2-test. 2) In a separate, equally sized geographical population of the same species, a rather different set of data was gathered: - Black hair, 24; Brown hair, 51: Yellow hair 25 What are the frequencies of the two alleles? Is this population in a Hardy-Weinberg equilibrium? 3) In humans, blue eye colour (B) is completely dominant to brown eye colour (b) [a hopeless oversimplification for argument's sake only]. In a certain population, the following data was gathered Blue eyes, 68; brown eyes, 32 What are the frequencies of the two alleles? Is it possible, in theory, to determine whether this population is in a Hardy-Weinberg equilibrium from the data given alone? (Hint: how many heterozygotes are among the blue eyed individuals?) 4) Consider the two populations in questions 1) and 2), above. Up to now they have been entirely separate, with no migratory contact between them. Suppose reciprocal migration begins between these two populations, at a level of m-0.05. That is, at each generation they exchange 5% of their members. Providing that no other factors direct allele frequencies, the populations will eventually become homogeneous. What will the allele frequencies be at this point? Show this trend graphically. On a single graph, show the frequencies of one of the alleles at each generation in each population. How would these curves change if the rate of migration were m = 0.01? m = 0.10? 5) What would be the heterozygosity of the two populations in questions 1) and 2)? What would be the fixation index between the two populations? On a single graph, depict the trends in heterozygosity in each subpopulation, and the trend in fixation index, after each round in migration, as described in question 4) 6) Consider a population of 20 individuals. A certain locus is polymorphic in this population for two selectively neutral alleles (i.e. distinct, but do not affect fitness), with frequencies f(A,)-0.70 and fA)-0.30. Because the population is so small, random genetic drift will probably occur, with the result that one of the two alleles will eventually be lost. What do you suppose is the probability that the A, allele will be lost? that the A, allele will be lost? How would this change if the population consisted of 2,000 individuals?Explanation / Answer
1. The answer is
Gene allele frequency estimation
Genotype
Freequency
Allele G
Allele g
Total
B1B1
18
36
0
36
B1B2
64
64
64
128
B2B2
32
0
64
64
Total
114
100
128
228
Allele freequencies
Allele G
100/228
0.44
Allele g
128/228
0.56
Expected genotype frequencies
Genotype Frequencies
B1B1
0.192
22
B1B2
0.492
56
B2B2
0.315
36
Null hypothesis: The expected values are not deviating from the observed values
Chisquare test:
Category
B1B1
B1B2
B2B2
Total
Observed values
18.00
64.00
32.00
114
Exprected Values
22
56
36
Deviation
-4
8
-4
D^2
16
64
16
D^2/E
0.727273
1.142857
0.444444
2.314574
X^2
2.314574
Degrees of freedom
3-2=1
Inference:
As the calculated chisquare value i.e. 2.31 is less than the table value i.e. 3.83 at 1 DF and 0.05 probability, hence the null hypothesis is accepted. Which indicates that the observed values are in HW equilibrium.
ACCORDING TO CHEGG GUIDELINES WE HAVE TO ANSWER ONE QUESITON AT A TIME. PLEASE POST THE REST AS SEPEARTE QUESTIONS. THEN I CAN HELP YOU.
Genotype
Freequency
Allele G
Allele g
Total
B1B1
18
36
0
36
B1B2
64
64
64
128
B2B2
32
0
64
64
Total
114
100
128
228
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