Hardy Weinberg Practice Problems

Hardy Weinberg Practice Problems

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Hardy-Weinberg Practice Problems

 

p² + 2pq + q² = 1 p + q = 1

 

Problem 1: 1 in 1700 US Caucasian newborns have cystic fibrosis. C for normal is dominant over c for cystic fibrosis.

 

1. When counting the phenotypes in a population why is cc the most significant?

 

2. What is the frequency of cystic fibrosis in the above population (cc or q²)?                                                                                                

 

ALLELE FREQUENCY CALCULATIONS:

 

3. Why calculate “q” first?      q =                      (frequency of c allele)

 

4. Why is it now easy to find “p”?      p =                      (frequency of C allele)

 

Now that you know p and q, the genotype frequencies can be calculated. GENOTYPE FREQUENCY CALCULATIONS:

5. CC- Normal homozygous dominant = p² =

 

6. Cc -carriers of cystic fibrosis = 2pq =                             

 

7. How many of the 1700 of the population are homozygous dominant (Normal)?

 

8. How many of the 1700 in the population are heterozygous (carriers)?

 

9. It has been found that a carrier is better able to survive diseases with severe What would happen to the frequency of the “c” if there was an epidemic of cholera or other type of diarrhea producing disease?

 

 

Problem 2: If 9% of an African population is born with a severe form of sickle-cell anemia (ss), what percentage of the population will be more resistant to malaria because they are heterozygous(Ss) for the sickle-cell gene?

 

p² + 2pq + q² = 1 p + q = 1

 

Problem 3: In a population that meets Hardy-Weinberg equilibrium, the dominant allele frequency (A) is 0.7. What is the frequency of homozygous recessive individuals?

 

 

 

 

 

 

 

Problem 4: In a population that meets Hardy-Weinberg equilibrium, 81% are homozygous for the recessive gene. What percentage of the population is expected to be homozygous dominant in the next generation?

 

 

 

 

 

 

 

 

 

 

 

Problem 5: In a population that meets Hardy-Weinberg equilibrium, 25% have the dominant phenotype. How many individuals are heterozygous for this trait in a population of 10,000?

 

 

 

 

 

 

 

 

 

 

 

Problem 6: In a population that meets Hardy-Weinberg equilibrium, the allele frequency is 0.36 dominant and 0.64 recessive. How many individuals in a population of 20,000 are expected to be homozygous recessive?