File - Biology with Radjewski
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15.3 PDQ
1. Fill out the chart
Hardy Weinberg Equations
P + Q =1
P2 + 2PQ + Q2 = 1
Required Conditions for HW Equilibruim
No net mutations
No natural selection
No gene flow
Large population size
Random Mating
2. What is the significance of the HW
equilibrium?
• It allows us to see if evolution is occurring in a
population
3.
• 1
If all of the above conditions hold, how many generations
are required for a population to reach HW equilibrium?
4. What do deviations from HW
equilibrium indicate?
• That evolution is occurring!
5. p. 299
A. Calculate the allele and genotype frequencies
of Ldh in this newly founded population?
Allele frequency of A = 10/20 = 0.5 = p
Allele frequency of a = 10/20 = 0.5 = q
AA Genotype frequency = 4/10 = 0.4 = P2
Aa Genotype frequency = 2/10 = 0.2 = 2pq
aa Genotype frequency = 4/10 = 0.4 = q2
5. p. 299 #b
• No because P2 does not equal 0.4, it equals
0.25. and Q2 does not equal 0.2, it equals
0.25.
5. #c
• Same
Allele frequencies:
p = 0.5, q = 0.5 (unchanged)
Genotype frequencies:
Frequency of aa = p2 = 0.25
Frequency of Aa = 2pq = 0.5
Frequency of AA = q2 = 0.25
•
#5 d
• Small population (only 10)
• Gene flow could occur (it happened before
due to the hurricane!)
• Random mating is not possible
• Selection for or against a trait could occur
Summarize the effect of the
following on allele frequencies
Mutations
If dominant mutation, p goes up; If
recessive mutation, p goes down etc.
Gene Flow
Emmigration would lower p and q;
Immigration would increase p and q
Genetic Drift
Random – p and q would change either
way
Non-Random mating
Chosen traits (dominant or recessive)
would go up
Natural Selection
Best fit traits for survival (dominant or
recessive) would go up