Throughout this document, you will find comments and instructions in red font. You should follow the instructions given, and ultimately delete the red text. Anywhere that you see text which is

[bracketed] this means you should be filling something in there. While the template is single spaced, please make your final version double-spaced. Be sure to check the rubric (published separately) to ensure that your report meets all expectations. Title This should be short, but informative. INTRODUCTION ▪ Your introduction should be succinct but also informative as to why you are doing this experiment - basically think of it as trying to outline the question you were seeking to answer. Think about linkage in general, why it might be important to figure out gene linkages in organisms other than Drosophila and how this might relate. Your textbook can be a good source of information regarding the importance of linkage studies. Your introduction should use information from your text and other published materials; be sure to cite them appropriately using academic (author date) style. Do the same with any other references you may use in preparing your report. o Example of an in-text citation: The chi-square test is useful for comparing categories of data (Griffiths et al. 2008). Note that you should not cite Griffiths et al. unless you actually used it in your preparation. Then, in your list of References at the end of your report, use this format: I Griffiths, A.J.F., S.R. Wessler, R.C. Lewontin, and S.B. Carroll. 2008. Introduction to Genetic Analysis. W.H. Freeman and Company, New York. Note that this entry is for a book. An entry for a journal article is slightly different (see below). ▪ Sherman, P. W., and M. L. Morton. 1984. Demography of Belding's ground squirrels. Ecology, 65(5), 1617-1628. You will also want to give a brief overview of the experiment you are going to describe, what sort of organisms you used (triple mutant true-breeding fruit fly lines and wild-type F1 heterozygote lines)./nMETHODS Here you can give a general description of the procedure used. Crosses that were made prior to your involvement, when and how you score flies, what sort of statistical tests you will perform, etc. This should be written in clear narrative text with complete sentences (not, for example, bullet points). The specific dates that you did particular parts of the procedure may be of interest to some and should be included. This should not be a laundry list of equipment and supplies, nor should it be a moment-by- moment account of what happened throughout the course of the experiment, but important details should not be omitted, either. As you have already performed these experiments, do not use future tense when writing your methods. A good guideline is that you should provide enough detail so that someone else could successfully replicate what you did in the experiment. Include a summary of the analyses you performed in this section-but do not reveal results. [Your name] Drosophila Chromosome Mapping Lab Report RESULTS AND DISCUSSION In this section you should give a narrative account of the laboratory work you performed, and what you found. This includes not just a description of your data and what it means, but also what you found in the analyses you performed. You will include your data in tables, but you also need to describe these data in the text of your report. You can refer to your tables and figures in this section. This is really going to be the core of your report. Take some time and organize it clearly. You may want to use smaller subheadings to organize this section./nF2 data Date observed % of total (1) btvg+bw+ (2) b vg bw Class Phenotype Freq (%) (1) b*vg+bw* (2) b vg bw (3) bvgbw* (4) b*vg bw (5) b*vg+bw (6) b vg bw* (7) bvg+bw (8) b'vg bw* (3) b vg+bwt Phenotypic classes (4) btvg bw (5) b*vg+bw (6) b vg bw* (7) b vg+bw (8) b*vg bw* TOTAL/n(crossing over between) A. b and vg B. vg and br C. b and br D. (double crossovers) Genes Thus, the distances between the loci can now be calculated using the sums of frequencies you calculated in the above A-D. Go ahead and do this and calculate the coefficient of coincidence and interference (see pp. 109-110 in Klug et al. for details on these descriptive statistics). b-vg vg-bw b-bw Classes distance Sum of frequencies of classes actual Double Crossover frequency expected Double Crossover frequency Coefficient of Coincidence Interference CHROMOSOME MAP On the line below, draw the chromosome map that you generated. (Put the three genes and the distance between each on the chromosome.) Note that this is a figure, not a table./nCHI-SQUARE ANALYSIS Now that you have calculated map distance, you will test to see if your results are significantly different than the null hypothesis of independent assortment. The table below will guide you through conducting a x² analysis of your data from this lab. You will enter the number of individuals scored in each phenotypic class (this is the same as the first table above) and total them. You will then generate an expected number of individuals for each class, based the null hypothesis of independent assortment. You should be able to determine predicted frequencies of progeny phenotypes, assuming independent assortment, and then multiply those by the total number of individuals counted. Now, you have both your observed and expected categories, and can perform the x² analysis. Once you have calculated the x² value, use the table on p. 51 of Klug et al. to determine a p-value. If your p-value is outside the range in the table, just use a greater-than or less-than symbol (> or <) with the p-value. You should also include interpretation of your statistical results as part of your analysis. For instance, now that you have generated a p-value, what does it mean? Phenotypic class (1) b+ vg+ bw+ (2) b vg bw (3) b vg+ bw+ (4) b+ vg bw (5) b+ vg+ bw (6) b vg bw+ (7) b vg+ bw (8) b+ vg bw+ Observed # of individuals (Independent assortment) # Expected (Obs-Exp)² Exp/nCONCLUSION You have now presented your data and the tests you performed on those data (the statistical tests) but here is where you really get to say what those statistical tests mean for your hypotheses. You should explicitly state whether you reject or do not reject your null hypothesis in this section. At this point you should be able to make some general statements about the success of the experiment, the meaning of your data, any problems that occurred and potential future directions to explore. This section need not be terribly long, but it should have a good sense of closure. FINAL NOTES: In this document, there are few other things of which you should be aware Page numbers and footer labels: these make a world of difference on any document. Always use them unless told otherwise - not only for this class, but for anything. They have been included in this document, but if you do not know how to use them, take this time to learn. Spelling and grammar are important. MS Word can check spelling and grammar, but you should always do so in any document. You should also proofread documents yourself as well. References: in writing your introduction, you may find you make some factual statements about biological concepts, statements that require some backing up-use references whenever you make such statements. Ensure that your sources are academic in nature (no websites). Plagiarism: Although the entire class did this experiment together (data were shared), each student should write their own report. You will submit your work to Canvas in electronic form and your work will be reviewed for evidence of plagiarism by Turnitin.com. Grading: this report and the work you did along the way will be worth 40 points.