Scholars Biology 3 Genetics Lab Report Searching for Correlations Between Phenotypes Refer to your syllabus for a more detailed description of items to be included in the lab report. Components of the Lab Report •Purpose •Methods •Results •Discussion •Literature Cited Purpose •Describe why the experiment was done •Identify the hypotheses being tested --1 hypothesis for simple inheritance --1 hypothesis for complex inheritance --2 hypotheses for taste perception Hypothesis for Simple Inheritance Choose any trait (EXCEPT short index finger) and determine whether the alleles are present in equal frequencies. (See p. 95 for details.) If the dominant and recessive alleles are present in equal frequencies, this Punnett square represents the ratio of expected offspring for the whole population. E e E e EE Ee Ee ee 75% free earlobes 25% attached earlobes Hypothesis for Complex Inheritance Multigenic Traits often show a range of phenotypes that approaches a normal distribution for numbers of individuals with each phenotype. For our experiment: Determine whether we see a normal distribution of heights with different central values for males and females. Hypotheses for Taste Perception Determine whether there is a relationship between 1. Supertaster and PTC-tasting phenotypes 2. Supertaster phenotypes and any ONE of the following: Gender Preference for Brussels sprouts Preference for Cheese Preference for Black coffee Preference for Dark chocolate Methods Provide a brief description of the techniques, materials and/or equipment used in the experiment. Emphasize how the methods accomplish the purpose given in the previous section. Focus on the determination of the phenotypes that are represented in your hypotheses, rather than all the traits tested. DO NOT write this section as a step-bystep guide for repeating the experiment. DO write it as a summary of the experimental procedure in past tense. Results • Present your experimental data in this section. • Introduce the reader to the data with a brief description that refers to the content of specific figures or tables. • Choose the most appropriate format for each type of data presented. – Simple Inheritance: Table or Histogram – Complex Inheritance: Line Graph – Taste Perception: Table or Histogram Results • Essential elements of a line graph or histogram – Put a label and specify the units on each axis – Make the plotted points or bars clearly visible – Connect related points by a best-fit line – Include a key to identify different lines, bars – Provide a caption BENEATH the graph or histogram • Brief description • Title – Number consecutively from Figure 1 Graphing the Data for Complex Inheritance 9 8 7 6 5 4 3 2 1 0 Males Females Class Male Average <1 49 15 515 9 16 516 9 17 517 9 18 518 9 19 519 9 Female Average Class Average Height (cm) Figure 1: Distribution of Heights in a Scholars’ Biology 3 Class During Fall Semester 2003. Heights of 25 students were grouped into the size categories shown. Displaying Data in a Histogram 0.8 0.7 0.6 0.5 Rolling 0.4 Can't Roll 0.3 0.2 0.1 0 1 Tongue-Rolling Phenotypes Figure 2: Frequency of Tongue-Rolling Trait in a Scholars’ Biology 3 Class During Fall Semester 2003. Phenotypes of 25 students were determined by visual observation. Results • Essential elements of a table – Provide a caption ABOVE the table • Title • Brief description – Present the data in clearly labeled columns and rows – Provide labels and units of measure if applicable – Number consecutively from Table 1 Displaying Data in a Table Table 1: Frequency of Mid-Digital Hair in a Scholars’ Biology 3 Class During Fall Semester 2003. Phenotypes of 25 students were determined by visual observation. Phenotype Percentage Mid-digital Hair 0.44 No Hairy Digits 0.56 Discussion Present your interpretation of the results in this section. Draw conclusions that are based on the experimental evidence. Discuss whether or not the original hypotheses were supported by the data. Explain any discrepancies in your data. Elaborate on the biological implications of the results.* Relate your results to existing scientific knowledge.* *See Dr. Colavito’s Other Links Web Page for more information on Supertasters. Literature Cited Include ONLY references cited in your report. To cite references in the text, use the format (Author, year). In the literature cited section, use the following format: For journal: Author, year, Title, Journal Name, volume number and pages For book: Author, year, Title, Publisher and City of publication For Web Page: URL and Date Accessed Length of Each Section Purpose: 1-2 paragraphs Methods: 1 page Results: 1 page + figures and tables Discussion 1-2 pages TOTAL LENGTH: 3-5 pages of written material Figures and tables should be included on additional pages.