Inheritance Lab Report
To develop and apply an understanding Mendelian inheritance patterns and Punnett squares.
Preparation (4 points)
Review the background document on inheritance and describe the concepts of dominant and recessive alleles, gametes, phenotype and genotypes.
Materials and Methods
Read the Inheritance Lab Background materials. No other materials are required for this lab. You will observe a variety of phenotypic characteristics in yourself and record these in the table in the Results section below. Using the logic of Mendelian genetics, you will then record your possible genotypes, as well as your parents’ possible genotypes. Do not refer to your parent’s phenotypes in order to infer the possible crosses that could have led to your phenotype.
Complete the following steps, and record your findings in the table in the Results section.
- Record each of your phenotypes in the Your Phenotype column. Identify your phenotype using a single letter for each trait as indicated below (capital letter indicates dominant allele, lowercase indicates recessive allele):
- Identify and record your possible genotypes based on your phenotypes. Genotypes are represented using two alleles. Identify the alleles using the letters indicated below (capital letter indicates dominant allele, lowercase indicates recessive allele):
- Using your possible genotypes, identify and record all of the possible pairings of parental genotypes that could have led to your possible genotypes. Crosses are denoted in this form: FF x Ff and indicates the genotypes of both parents. You should list all of the possible crosses that could lead to your phenotype.
Preliminary Analysis (4 points)
Describe how a genetic trait can skip one or more generations without being apparent. How might one learn about unseen alleles in a child’s parents by observing traits in the child?
Results (26 points)
Use the chart below to record the observations of your phenotypes and to record your inferences regarding your genotype and all of the possible crossings of parental genotypes that can account for your genotype. Phenotypes are expressed with a single letter related to the trait. Genotypes include both alleles and are, thus, expressed with two letters (one for each allele). Possible parental genotypes and crosses consist of two genotypes crossed. For instance, a freckled person will have a phenotype of F and possible genotypes of FF and Ff. One of the possible parental genotype and crosses is (FF x Ff). Be sure to list all possible parental genotypes in terms of possible crosses. Crosses are denoted in this form: FF x Ff and you should list all of the possible crosses that could lead to your phenotype.
Analysis (12 points)
Write an analysis of two or more paragraphs that includes the following:
- A summary of your results and the overall knowledge you gained from this lab
- Explain the cellular basis for one component of your genotype coming from each parent.
- Describe how Punnett squares are related to cell division.
- An example of how Mendelian logic could be useful
Conclusion (4 points)
Write a conclusion of two or more paragraphs that includes the following:
- A brief recap of the main points in your analysis
- Propose a research question about this lab topic that you would like to answer in the future.