Biology 22 Laboratory Report 1 Winter 2010 Analysis of Body Color Inheritance and Genetic Mapping in Fruit Flies

Refer to pages 1-23  1-26 of the lab manual for a written description of the lab report.

Format of Laboratory Report  Title  Statement of Hypothesis  Results  Discussion  Conclusion

Title The title should include the purpose(s) of the experiment(s) the name of the experimental organism or system eg. Saccharomyces cerevisiae or cell lysate

Statement of Hypothesis  This section should include  the hypothesis you have formulated for the inheritance of body color in fruit flies.  a brief rationale for the chosen hypothesis, considering the data as a whole. You will give a more detailed account of your reasoning in the discussion section.

Results Present your experimental data in this section. Report your data and calculated values in tabular format. Sample tables are shown on pages 1-25  1-26 of the lab manual. Tables are numbered sequentially. Place a meaningful caption above each table. Each caption needs a title and brief description explaining the source of the data. Write a brief narrative to orient the reader to the data shown in specific tables.

Results Body Color Inheritance Phenotypes of Parents and Offspring for each Cross Proposed Genotypes and Genetic Ratios for each Cross Chi-square Analysis for each Cross

Results Three-Point Testcross Observed Numbers of Offspring in Each Phenotypic Class Gene Order and Map Distances between the genes

Discussion  Present your interpretation of the results in this section.  Show how you deduced the hypothesis, explain how it was tested and indicate whether the hypothesis is supported by the data.  Provide a brief error analysis. See pages 1-23  1-24 for questions to guide your analysis of the data.

Discussing Body Color Inheritance Build your discussion around the answers to the following questions:  How did you determine whether the yellow body color allele is dominant or recessive?  How did you determine whether the yellow body color allele is autosomal or sex-linked?  Considering the chi-square analysis, how well does the data fit your hypothesis?  Propose plausible sources of variation for any discrepancies you observe.  Considering the entire set of data, has your hypothesis been supported by this experiment?

Discussing Genetic Mapping Build your discussion around the answers to the following questions:  How did you determine the gene order?  How did you determine the gene distances?  How well does this data fit with expected values?  Propose plausible sources of variation for any discrepancies you observe. bl vg bw bl vg bw ?

Conclusion  This is a concise summary of all of the results expressed in a 2-3 sentence conclusion.  For example: “These data indicate that mutations in genomic DNA increase with age and that the rate of these mutations occurs faster in men than women.”

Length of each section (written material)  Statement of Hypothesis: 1 paragraph  Results: 1-2 pages (longer if tables are included)  Discussion 2-3 pages  Summary: 2-3 sentences  TOTAL LENGTH: 4-6 pages of written material  Tables can be included on additional pages or integrated into the text, as you prefer.