Genetics and Probability Purpose: To gain some experience with the rules of probability and to think about the relationship between probably outcomes and actual events. Procedure: 1.) In your groups, you will be flipping coins and recording data – have two people flip coins and the other group member(s) record data. 2.) In your lab notebooks, answer the following question: With each flip of a coin, what is the probability that the coin will land on heads? On tails? 3.) Now, in your lab notebook record a prediction for the outcome of 4 flips of a coin (How many will land heads up? How many will land tails up?) 4.) The two coin flippers should both toss their coins 4 times and the recorder(s) should record the outcome of each toss for each flipper. (It would be helpful to create a table here to organize data!) 5.) Now, everyone should record a prediction for the outcome of 100 flips of a coin (How many will land heads up? How many will land tails up?) 6.) Each “flipper” should toss their coin 100 times. Once again, the recorder(s) should record the outcome for each toss for each flipper. 7.) After completing steps 1-6, both flippers will again toss their coins 100 times. However this time, the flippers should toss their coins TOGETHER so that the recorder(s) can record the following information: a.) How many times BOTH coins came up heads b.) How many times BOTH coins came up tails c.) How many times one coin was heads while the other was tails 8.) After completing the data collection, everyone in the group should record the data and organize it into tables for steps 4, 6 and 7. 9.) Now, make 2 bar graphs in your lab notebook – 1 graph for the data for step 6 for each flipper and 1 graph for the data for step 7. Be sure to label axes and give your graphs titles! 10.) Answer the analysis questions in your lab notebook. Analysis Questions 1.) Write down the definition of probability in your own words. 2.) Explain why you made the predictions that you did for steps 4 and 6. 3.) How closely did the predictions you made for steps 4 and 6 match the actual outcome of your coin tosses – describe! 4.) Why is tossing a coin 100 times more likely to yield a 50/50 ratio of heads to tails than tossing a coin only 4 times? 5.) In genetics, what could each side of a coin represent? 6.) How do your results for step 7 relate to the genotype ratios that Mendel found in the F2 generation of his monohybrid cross (remember – this was a cross between 2 individuals that were heterozygous for one trait)?