23.5 In Class Activity Hardy-Weinberg Worksheet PDF

Preview

Summary

ACtivity sheet was done in class chapter 23.5 Hardy-Weinburg worksheet....

Description

In Class Activity Hardy-Weinberg The equations p + q = 1 and p2 + 2pq +q2 = 1, were first developed by G. H. Hardy and Wilhelm Weinberg. They represent the distribution of alleles in a population when • The population is large. • Mating is random. • All genotypes are equally likely to reproduce (there is no natural selection). • No organisms enter or leave the population (there is no immigration or emigration). • No mutations occur. In other words, the group of alleles available in the population must be very stable from generation to generation. If the distribution of genotypes in a population matches that predicted by the Hardy- Weinberg equation, then the population is said to be in Hardy-Weinberg equilibrium. If the distribution of genotypes in a population does not match that predicted by the Hardy-Weinberg equation, then the population is said to be evolving.

Part I. In each of the following scenarios, determine which assumption of the Hardy–Weinberg theorem is being violated. Explain your answer.

1. Consider the requirements for a population to be in Hardy-Weinberg equilibrium. In the natural world, are populations likely to be in Hardy-Weinberg equilibrium? Justify your reasoning.

2. In a particular region of the coast, limpets (a type of mollusk) live on nearshore habitats that are uniformly made up of brown sandstone rock. The principal predators of these limpets are shorebirds. The limpets occur in two morphs, one with a light-colored shell and one with a dark-colored shell. The shorebirds hunt by sight and are able to see the light ones on the dark sandstone easier than the dark ones.

3. In Chen caerulescens (a species of goose), the white body form—the snow goose— and the blue body form— the blue goose—occasionally coexist. In these areas of contact, white-by-white and blue-by-blue matings are much more common than white-by-blue matings.

4. Prior to the Mongolian invasions that occurred between the 6th and 16th centuries, the frequency of blood type B across Europe was close to zero. The frequency of blood type B among the Mongols was relatively high. Today, it is possible to see fairly high frequencies of blood type B in the eastern European countries and a gradual decrease in the frequency of blood type B as one moves from the eastern European countries to the western European countries (e.g., France and England).

1

Part 2: Analyzing the gene pool of a hypothetical population

5. A hypothetical population of 200 cats has two alleles, T L and TS, for a locus that codes for tail length. The table below describes the phenotypes of cats with each possible genotype, as well as the number of individuals in the population with each genotype. Which statements about the population are true?

Heterozygotes make up 20% of the population. Homozygotes make up 80% of the population. Homozygotes make up 30% of the population. In the entire cat population, 60% of the alleles are TS. In the entire cat population, the frequency of the TS allele is 0.5. In the entire cat population, the frequency of the TL allele is 0.4. Assuming random mating, each gamete has a 50% chance of having a T L allele and a 50% chance of having a TS allele. Assuming random mating, each gamete has a 40% chance of having a T L allele and a 60% chance of having a TS allele.

6. Enter the values for the expected frequency of each genotype: T L TL, TL TS, and TS TS. Enter your answers numerically to two decimal places, not as percentages. Genotype TL TL TL TS TS TS

Phenotype

# of individuals in population

Expected frequency

Part 3: Using the Hardy-Weinberg equation to determine if a population appears to be evolving

7. A hypothetical population of 300 wolves has two alleles, FB and FW, for a locus that codes for fur color. The table below describes the phenotype of a wolf with each possible genotype, as well as the number of individuals in the population with each genotype. Which statements accurately describe the population of wolves? Select the four statements that are true.

Based on the equation for Hardy-Weinberg equilibrium, the expected number of wolves with the F BFB genotype is 40. Based on the equation for Hardy-Weinberg equilibrium, the expected number of wolves with the F BFB genotype is 12. Based on the equation for Hardy-Weinberg equilibrium, the expected number of wolves with the F BFW genotype is 40. Based on the equation for Hardy-Weinberg equilibrium, the expected number of wolves with the F BFW genotype is 96. The population is not evolving because it is at Hardy-Weinberg equilibrium. The population is not at Hardy-Weinberg equilibrium. The population may be evolving because the actual number of individuals with each genotype differs from the expected number of individuals with each genotype.

3...