Conceptual Questions
What is population genetics?
Allele frequency changes that underlie evolution
There are 100 cows
3 are completely white (bb)
40 are brown with white spots (Bb)
57 are brown (BB)
What is the frequency of the b allele?
0.23
In a population of 1000, the frequency of the genotype bb for a particular gene is bb=0.16
Assuming the population is in Hardy-Weinberg equilibrium, how many individuals are expected to be heterozygous?
480 individuals
There is a population of elephants with known genotypes:
AA has 6 offspring on average
Aa has 7 offspring on average
aa has 3 offspring on average
What is the relative fitness for AA?
6/7=0.86
What is fitness?
an organisms ability to pass on it's genes
There are 50 zebrafish
4 have a spine deformity (vv)
7 will develop a spine deformity (Vv)
39 have normal spines (VV)
What is the frequency of the Vv genotype?
0.14
What two things are the Hardy-Weinberg Equation used for?
1 Relate allele frequencies and genotype frequencies
2 Predict that allele frequencies remain the same in a population under certain conditions
What is the mean fitness of this population?
Starting allele frequencies are R=0.6 and r=0.4
Fitness values are 1.0, 0.8 and 0.2 for genotypes AA, Aa, and aa respectively
0.776
What is balancing selection?
a type of natural selection that maintains multiple gene variants instead of favoring one variant over time
Calculate the allele frequencies of A(p)at equilibrium under balancing selection given the following fitness values
wAA=0.5
wAa=1.0
waa=0.2
p=0.385
What are the expected frequencies of genotypes MM, Mm, and mm given p=0.7
MM=0.49
Mm=0.42
mm=0.09
A population under balancing selection has starting allele frequencies of A=0.7 and a=0.3. Fitness values are 0.9, 1, and 0.3 for genotypes AA, Aa, and aa respectively.
What is the frequency of the Aa genotype at equilibrium?
0.2288
What are the conditions necessary for Hardy-Weinberg equilibrium?
No new mutations, No genetic drift, No migration, No natural selection, Yes random mating
A population has a recessive allele frequency (q) of 0.2. What is the frequency of heterozygous individuals (2pq)?
0.32
A gene exists as 2 alleles in a population C and c. the recessive cc genotype causes a disease in 16% of the population. What is the frequency of heterozygote carriers?
0.48
There is a population of endangered ferrets being monitored. The population has allele frequencies of F=0.7 and f=0.3. The fitness values are AA= 1.0, Aa=0.8, and aa=0.2
What is the mean fitness of the second generation?
0.892