# Hardy-Weinberg Problems

## Presentation on theme: "Hardy-Weinberg Problems"— Presentation transcript:

Hardy-Weinberg Problems

1 In Drosophila, the allele for normal-length wings is dominant over the allele for vestigial wings. In a population of individuals, 360 have vestigial wings. How many individuals would you expect to be homozygous dominant and heterozygous for this trait?

2 The allele for unattached earlobes is dominant over the allele for attached earlobes. In a population of 500 individuals, 25% show the recessive phenotype. How many individuals would you expect to be homozygous dominant and heterozygous for this character?

3 The allele for the hair pattern called "widow’s peak" is dominant over the allele for no "widow’s peak." In a population of individuals, 510 show the dominant phenotype. How many individuals would you expect of each of the possible three genotypes for this trait?

4 In the U.S. about 16% of the population is Rh negative. The allele for Rh negative is recessive to the allele for Rh positive. If the student population of a high school in the U.S. is 2000, how many students would you expect for each of the three possible genotypes?

5 In certain African countries 4% of the newborn babies have sickle-cell anemia, which is a recessive trait. Out of a random population of 1,000 newborn babies, how many would you expect for each of the three possible genotypes?

6 In a certain population, the dominant phenotype of a certain trait occurs 91% of the time. What is the frequency of the dominant allele?

7 Within a population of butterflies, the color brown (B) is dominant over the color white (b). And, 40% of all butterflies are white. Given this simple information, calculate the percentage of butterflies in the population that are heterozygous and the frequency of homozygous dominant individuals.

8 After graduation, you and 19 of your closest friends (lets say 10 males and 10 females) charter a plane to go on a round-the-world tour. Unfortunately, you all crash land (safely) on a deserted island. No one finds you and you start a new population totally isolated from the rest of the world. Two of your friends carry (i.e. are heterozygous for) the recessive cystic fibrosis allele (c). Assuming that the frequency of this allele does not change as the population grows, what will be the incidence of cystic fibrosis on your island?

9 Cystic fibrosis is a recessive condition that affects about 1 in 2,500 babies in the Caucasian population of the United States. Please calculate the following. The frequency of the recessive allele in the population. The frequency of the dominant allele in the population. The percentage of heterozygous individuals (carriers) in the population.

10 The ability to taste PTC is due to a single dominate allele "T". You sampled 215 individuals in biology, and determined that 150 could detect the bitter taste of PTC and 65 could not. Calculate all of the potential frequencies.