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Hardy-Weinberg Problems. Problems 1, 2 and 4 from http://nhscience.lonestar.edu/biol/hwe.html Problem 3 from http://science.kennesaw.edu/~rmatson/Biol%203380/PROBLEMS.html. Hardy-Weinberg Problems. 1. Scientists observe that 9% of an African population is born with sickle-cell anemia (ss).
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Hardy-Weinberg Problems Problems 1, 2 and 4 from http://nhscience.lonestar.edu/biol/hwe.html Problem 3 from http://science.kennesaw.edu/~rmatson/Biol%203380/PROBLEMS.html
Hardy-Weinberg Problems • 1. Scientists observe that 9% of an African population is born with sickle-cell anemia (ss). • A. What percentage of the population will be more resistant to malaria because they are heterozygous (Ss) for the sickle-cell gene? • B. What percentage is homozygous normal (SS)?
C. If there are 100 people in this population, how many people are there in each category? • D. If there are 100 people, how many S alleles are there? • E. If there are 100 people, how many s alleles are there?
2. Scientists visit the same area many years later and observe a new generation of the same population. Now, 5% of the population is born with sickle-cell anemia (ss). • A. Answer the same questions as you did in problem 1. Use 5% instead of 9%; the population is still 100 people.
B. Is this population in Hardy-Weinberg equilibrium? One way to answer the question is by conducting a chi-square analysis. • If there is equilibrium (i.e., no evolution), what would the expected numbers for each category in the 5% population be? • What are the actual numbers that you found in problem 2? • State the null hypothesis that you will test. • Perform a chi-square test to determine whether your null hypothesis is accepted or rejected. • Is the population in equilibrium or is it evolving? Explain.
3. A study on blood types found the following distribution among the population sampled: • 1101 were MM, 1496 were MN, 503 were NN • Calculate the genotype frequencies • Calculate the allele frequencies of M and N
4. After graduation, you and 19 friends build a raft, sail to a deserted island, and start a new population, totally isolated from the world. Two of your friends carry the recessive allele for cystic fibrosis (Ff) and the rest of you are normal (FF). • If the frequency of this allele does not change as the population grows, what will be the frequency of cystic fibrosis on the island? • How does this compare to the the mainland (0.059%)?
5. In the initial population of grebes in class on Wednesday, there were 13 Aa, 6aa, and 7 AA grebes. • What was the initial allele frequency (p and q)? • What was the initial frequency of p2, 2pq, and q2? • What would you expect at the end of five generations if the grebe population were in Hardy-Weinberg equilibrium?