Write an essay describing a scenario that illustrates one of the three types of natural selection.

Choose one of the following:

- Directional selection:

selects for one extreme of a

specific trait

- Disruptive selection: selects for BOTH extremes of a specific trait

- Stabilizing selection: selects for the average of a specific trait

 

Your essay must include the following:

- A description of the chosen type of selection

- An organism and population

- Three different variations of a specific trait

- How the population shifted from one version of the trait to another and why

- Your reasoning as to how this scenario models this type of selection

This activity will simulate what occurred in the population of peppered moths during the -trial Revolution and you will answer questions and make inferences about it.

 

The Industrial Revolution was a time in Europe when there was a massive increase in industry and factories. Methods of production shifted from handicraft to machine, along with the use of new materials like iron and steel, and new energies like coal, steam engines, electricity, and combustion engines. The large number of new factories put out large quantities of smoke and created a dramatic rise in pollution.

 

The Peppered Moth population was significantly affected by the Industrial Revolution. Prior to this time period peppered moths used to be white and lightly colored and were only rarely peppered or black in color. These moths lived in a forest full of Aspen trees with light colored bark, and their light coloring allowed them to camouflage for protection. After the Industrial Revolution, scientists noticed there was a drastic increase in the number of peppered and black moths and a decrease in the number of white moths. The Industrial Revolution caused a change in the habitat of the peppered moths, and the makeup of their population shifted as a result. Scientists believe that this is due to natural selection.

 

For this assignment you will count the number of each type of moth in a set of images and then make inferences about what you notice. You will answer questions about the images and the possible causes of the shift in coloration of the peppered moth.

 

Submission:

Answer the questions for each image as well as the discussion questions and submit your work. A grading rubric is included below the questions for this assignment.

 

Overview:

In this assignment you will review Punnett squares and their use in predicting the genetic makeup of offspring. Then you will be given three different scenarios and use Punnett squares to predict the likelihood of the genotypes and phenotypes of the offspring.

 

Probability is the likelihood that an event will occur. Geneticists use Punnett squares to determine the probability that each potential genotype will occur in a genetic cross. A specific genetic trait has both a genotype and a phenotype. The genotype represents the genes that are present for a specific trait. The phenotype is the physical representation of that trait.

 

The genotype of specific traits represents both dominant and recessive alleles. An allele is a form of a specific gene found at the same point on a strand of DNA. A dominant allele is represented as a capital letter and a recessive allele is represented by a lowercase letter. A dominant trait means that it will mask or cover a recessive trait. An organism's genetic traits contain two alleles because one is inherited from each parent. If an organism has two of the same alleles, then their genotype is called homozygous. A trait with two dominant alleles would be called homozygous dominant. Two recessive alleles would be called homozygous recessive. If an organism has two different alleles, their genotype is called heterozygous, which means one allele is dominant and one allele is recessive.

 

There are cases where heterozygous alleles don't completely mask one another. Incomplete dominance is where a mixture of the trait for each allele is present in the phenotype. Codominance is where both alleles are present in the phenotype.

 

In this assignment, you will research a genetic disorder and write an essay describing what you have learned. The essay should include information about the genetic mutation that causes the disorder, the causes and effects of the mutation, and how it is inherited or acquired.

 

Genetic disorders are caused by mutations in the DNA. These mutations can be passed on from the parents, occur spontaneously, or develop over time. Genetic mutations can cause many different effects and symptoms as well as both advantages and disadvantages.

 

For this assignment you will start by researching and learning about a specific genetic disorder. You should research information about what gene mutations or change causes the disorder, how or if it is inherited, symptoms or changes that it causes, and how common it is.

 

Once you have researched a genetic disorder, you will develop an essay. The essay should answer all questions in the Writing Prompt.

Choose a genetic disorder to research. Write an essay describing your chosen genetic disorder. Your description should include information about the genetic mutation that causes the disorder, the effects and symptoms of the mutation, how it is acquired, and how common it is. Additionally, is there anyone famous or important who has ever had this disorder? Does the disorder have any advantages?