Biology 22Laboratory Report 1
Winter 2010
Analysis of Body Color Inheritance and Genetic Mapping in Fruit Flies
Refer to pages 1-231-26 of the lab manual for a written
description of the lab report.
Format of Laboratory Report
TitleStatement of
HypothesisResultsDiscussionConclusion
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 CrossChi-square Analysis for each Cross
Results
Three-Point Testcross
Observed Numbers of Offspring in Each Phenotypic ClassGene 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 1-231-24 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 vgbw?
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 paragraphResults: 1-2 pages (longer if tables are included)Discussion 2-3 pagesSummary: 2-3 sentencesTOTAL LENGTH: 4-6 pages of written
materialTables can be included on additional pages or
integrated into the text, as you prefer.