Chap 24:
Population Genetics
Supplemental Instruction
Iowa State University / Leader: / Adam
Course: / Biology 211
Instructor: / Dr. Holscher
Date:

1.  All of the alleles for every gene in a given population is called a?

2.  What two letters represent allele frequencies?

Two population genetics calculations:

1.  Allele frequency:

2.  Genotype frequency:

Worked Problem:

You are a small organic farmer. You go out into your garden and picked 170 cucumbers. You notice some are smooth, some are rough, and some are indented on their skin. There are two alleles for cucumber skin: C^R and C^I. You look more closely and have 89 cucumbers that are rough (C^R,C^R), 66 cucumbers are smooth (C^R,C^I), and 15 that are indented (C^I,C^I). The organic cumbers are diploid.

a.  What is the allele frequency of C^R

b.  What is the allele frequency of C^I

c.  What is the genotype frequency of rough skin, smooth skin, and indented skin.

Hardy-Weinberg equation:

a.  Describes a population that is not….. evolving

b.  Used to estimate the percentage of a ______carrying the ______for an inherited disease

Population, allele

c.  States that the frequencies of alleles and genotypes in a population will remain ______from generation to generation provided that only ______segregation and recombination of alleles are at work. Constant, Mendelian

The Hardy-Weinberg equation: p2 + 2pq+q2=1

p^2 & q^2 represents:

2pq represents:

Question: Using the Hardy-Weinberg equation (show calculations), what is the frequency of rough, smooth, and indented cucumbers?

Question: A certain disease affects 1 out of every 800 babies born. This disease is a result of a homozygous dominant allele. Using the Hardy-Weinburg equation find the recessive, dominant, and carrier allele percentage in the population.

5 conditions are required to reach Hardy-Weinberg equilibrium:

1. 

2. 

3. 

4. 

5. 

1.  Natural Selection:

a.  When ______traits that are heritable become more ______in successive generations.

b.  Over time it results in ______

c.  Natural Selection favors individuals with two distinct advantages

2.  The relative likelihood that a genotype will contribute to the gene pool of the next generation as compared to other genotypes describes what?
a.  Is a measure of ______.
b.  Acts more directly on the ______than on the ______.
3.  Sexual Selection (type of natural selection)
  1. Affects ______characterstics more intensly than ______characteristics

1.  Intrasexual selection:

2.  Intersexual selection: