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.