Product and Probability Rules - BIOL 2153 Read Ch 3 No class Oct 3 5 Sept 7 1 For a set of bi-allelic genes in which one of the alleles is completely

BIOL 2153 Sept 7 Read Ch. 3 No class Oct 3 & 5 1. For a set of bi-allelic genes in which one of the alleles is completely dominant over the other (must be heterozygous) a. # of possible phenotypes is 2 n , where n is the # of genes AABbCc = 2 2 = 4 2. To calculate the number of gametes, multiply the number of possible gametes for each gene Aa= 2 Bb=2 2x2=4 gametes AaBBCcdd = 4 gametes (for each gene decide how many types of gametes it can produce homozygous can only produce one) 3. Probability Rules a. Product rule - states that the probability of 2 or more independent events occurring together is the product of the probabilities that each event will occur by itself prob (h)= ½ prob (t)= ½ prob (h,t) and (t, h) ¼ + ¼ = ½ b. Sum rule - states that the probability of either of two mutually exclusive events is the sum of their individual probabilities. ----Problem 2-10 : what is the probability of rolling a 6? 1/6 *What is the probability of rolling an even number? 3/6 2 : 1/6 4: 1/6 mutually exclusive: added equals 3/6 6: 1/6 *What’s the probability for rolling a # divisible by 3? 1/6 + 1/6 = 1/3