Bio Lab

September 18, 2011
Period 8 AP Bio
Ms. Dahle
September 12, 2011
TITLE: Population Genetics and Evolution Within a Gene Pool
INTRODUCTION: The Hardy-Weinberg scheme is a way of viewing evolution as changes in the frequency of alleles in a population of organisms. If A and a are alleles for a particular gene and each individual has two alleles then p is the frequency of the A allele and q is the frequency of a alleles. The frequency of the possible diploid combinations is expressed in the equation p2+2pq+q2=1. In order for the Hardy-Weinberg equation to work five conditions must be met:
  1. The breeding population must be large.
  2. Mating must be random.
  3. There must not be mutations of the alleles.
  4. No differential migration may occur.
  5. All allele combinations must survive equally.
If the conditions are met then the allele genotype frequencies in a population remain the same.
HYPOTHESIS:
8A: If we use PTC paper to determine the allele frequencies for the dominant and recessive alleles in our classroom population, then we can use the Hardy-Weinberg equation to determine the number of homozygous dominant, heterozygous, and homozygous recessive individuals.
8B: If the requirements for the Hardy-Weinberg equation are met, then the predictions of the allele frequencies by the Hardy-Weinberg equations will be similar to the actual allele frequencies.
MATERIALS:
8A:
~PTC paper
8B:
~Note cards
PROCEDURE:
8A:
  1. Using the PTC paper, rip off a piece and press it to the tip of your tongue. PTC tasters will sense a bitter taste. These individuals are considered tasters.
  2. A number representing the frequency of tasters (p2+2pq) should be calculated by dividing the number of tasters by the total number of students. A number representing the frequency of nontasters (q2) should be obtained by dividing the number of nontasters by the total number of students.
  3. Use the Hardy-Weinberg to determine the frequencies of the... [continues]

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