Download frequency

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)
3. What do each of the variables represent
in the Hardy-Weinberg equation?
a) P: dominant alleles
b) Q: recessive alleles
c) q2: homozygous recessive
d) 2pq: heterozygous
e) p2: homozygous dominant
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.
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
 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.
 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.
 q2
 Q
 P
 p2
 2pq