Name ____________________________________
Period ______
Date _______________
Hardy-Weinberg Grid-In Practice Problems
Grid-In Questions.
1. Grid-in each final answer FROM LEFT TO RIGHT
2. Don’t round until the end, then round your answer according to the instructions
provided in the question (example: “Round to the nearest tenth”)
1. A naturalist working on Isabella Island in the Galapagos observes that 24 nesting birds show a
rare recessive condition that affects beak formation. The remaining 63 birds in this population
show no beak defect. If this population is in Hardy-Weinberg equilibrium, what is the
frequency of the dominant allele? Round to the nearest hundredth.
q = square root of 24/87 = 0.53
p = 1-.53 = .47
2. The table below summarizes the association between the genetics of sickle-cell disease and
resistance to the infectious disease malaria. For a population at Hardy-Weinberg genetic
equilibrium, if 250 out of 1000 people are homozygous for sickle cell disease (SS), how many
people in the population are expected to show increased resistance to malaria? Round to the
nearest whole number.
q = square root of 250/1000 = .5
p=1-q = .5
2pq = 2(.5)(.5) = .5 .5X1000 = 500
3. In a certain population of birds, the allele for a crown on the head (C) is dominant to the
allele for no crown on the head (c). A particular cold and long winter favored the birds
with no crowns. When spring came, researchers determined that the population was
currently in Hardy-Weinberg Equilibrium and that the occurrence of the birds with no
crown was up to 24%. What will the frequency of the no-crown allele be in 10 years?
Round your answer to the nearest hundredth.
q = square root of .24 = .49
10 years doesn’t matter because population is in
equilibrium (allele frequencies should not change)
4. If the genotype frequencies of an insect population are AA = 0.49, Aa = 0.42, and
aa = 0.09, what is the gene frequency of the dominant allele? Round your answer to the
nearest tenth.
q = square root of .09 = .3
p = 1-q = .7
5. If a population has 500 individuals and 127 have the bb genotype, assuming simple
dominance of the B alleles, what is the frequency of the Bb genotype? Round your answer
to the nearest hundredth.
q = square root of 127/500 = .50
p = 1-q = .50
Bb = 2pq = 2(.5)(.5) = .50