1. 1. Define the following terms:  Genetic drift: random change in a gene frequency that is caused by a series of chance occurrences that cause an allele to become more or less common in a population  Gene pool: a stock of different genes in an interbreeding population  Genetic equilibrium: situation in which alleles frequencies in a population remain the same (no evolution occurring) 2. What are the five conditions for Hardy-Weinberg equilibrium? 1. No mutations occur 2. Immigration and emigration do not occur 3. Population is very large 4. Mating is random 5. No natural selection occurs (populations must be isolated)

2. 3. What do each of the variables represent in the Hardy-Weinberg equation? a) P: dominant alleles b) Q: recessive alleles c) q 2 : homozygous recessive d) 2pq: heterozygous e) p 2 : homozygous dominant

3. 4. What occurs in each of the selections below and draw a graph on the side to show this selection a. Disruptive selection: when individuals in the extreme ends of the curve have a higher fitness than the individuals in the middle of the curve (average phenotypes disappear) b. Stabilizing selection: when individuals near the center of the curve are better adapted to the environment (extreme phenotypes disappear) c. Directional selection: when the environment changes and one extreme phenotypes has a higher fitness (one extreme phenotype will disappear)

5. 5. You have sampled a population in which you know that the percentage of the homozygous recessive genotype (aa) is 36%. Using that 36%, calculate the following: a. The percent of the "aa" genotype. b. The frequency of the "a" allele. c. The frequency of the "A" allele. d. The percent of the genotypes "AA" e. The percent of the genotypes "Aa” f. The percent of the dominant phenotype g. The percent of the recessive phenotype

6.  There are 100 students in a class. Ninety-six did well in the course whereas four blew it totally and received a grade of F. Sorry. In the highly unlikely event that these traits are genetic rather than environmental, if these traits involve dominant and recessive alleles, and if the four (4%) represent the frequency of the homozygous recessive condition, please calculate the following:  The frequency of the recessive allele.  The frequency of the dominant allele.  The frequency of heterozygous individuals.

7.  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.  q 2  Q  P  p 2  2pq