Mendel's third and fourth general principles were: "segregation" and "independent assortment." What is the evidence from your experiment that supports or refutes these principles? You will need to use your data to test these and to draw some conclusions. Do you expect the reciprocal crosses to show any difference in their genotypic ratios? Test each set of data using Chi Square analysis to see if your group's data or the class data give a result closer to the expected data. You will write a report on this lab. The instructor will discuss how it should be organized. The report should include a clear presentation of your data, a calculation of the map distance, and a comparison of your map with the well-established map of the Drosophila X chromosome. To do this final step, you will determine the expected number of progeny in each of the 2 categories, parental or non-crossover (NCO), and single crossover (SCO), using the map distances from the book. You will use the total number of male progeny scored by you and your partners. For example, suppose you are looking at hypothetical genes "a" and "b," and you know the map distance between two genes is 20 map units: 20 b Suppose you score 300 flies. Since 20% of the 300 progeny (60 flies) are expected to show recombination between a and b, then the expected SCO category is 60. That is, SCO/total = 60/300 = 20%, the map distance between "a" and "b." The expected NCO category would be the remainder, 300 – 60 = 240.