BIO 123 PROBABILITY AND GENETICS LAB REPORT AND ANSWERS

BIO 123 PROBABILITY AND GENETICS LAB REPORT AND ANSWERS 1. Based on the parents' genotypes, what is the genotypic ratio expected from a monohybrid cross between the two parents for the trait? The genotype of both parents is Bb. Hence, after monohybrid cross, the genotype ratio can be determined as follows: The F1 generation will have genotype ratio BB:Bb:bb= 1:2:1. B b B BB Bb b Bb bb 2. Based on the genotypic ratio from question 1, what is the expected probability of each genotype? 3. Toss the coins together 50 times and keep a tally sheet while doing so. They can only turn up as BB, Bb, or bb. Remember: each coin represents each parent and each toss can only turn up one way, therefore, a parent can give only one gene of a pair. How many tally's for each genotype did you get? 1. BB 2. Bb 3. bb BB = 15 Bb = 24 bb = 11 4. Determine the actual probability in percent, that each genotype occurred. 1. BB 2. Bb 3. bb BB = 30% Bb = 48% bb = 22% 5. How close did your actual results come to your expected results? What caused the difference? The actual results are quite close to the expected result, and the differences may occur just because of random nature of the experiment. EXPECTED RESULT ACTUAL RESULT BB 13 15 Bb 25 24 bb 12 11 6. What fraction of actual BB, Bb, bb did you record? How close is it to the expected ration Mendel predicted? It is approximately equal to the Mendel's expected ratio. EXPECTED RESULTS ACTUAL RESULTS BB 1/4 1/3.3 Bb 1/2 1/2 bb 1/4 1/4.5