Feeling Lost?? Why Do They Matter? They occur during the second part of Meiosis a. Produces eggs and sperm cells. 2. Because of the law of segregation, it ensures that each egg or sperm receives one copy of each chromosome. Why does that matter? This reduction division keeps the chromosome number consistent between the generations of parents & offspring. 1. 23 23 46 Why Do They Matter? 3. Because of the law of independent assortment, it provides variation in the offspring so that they all do not look the same and have the same characteristics. 4. Statistically, it is POSSIBLE for all offspring to resemble each other, but it is IMPROBABLE that they will It’s the equivalent of the genetic lottery! Understanding the Law of Segregation Segregation: The act or process of separating or setting apart. As the name of this implies, segregation means that certain things are being separated from each other. So, what is being separated? The homologous pairs of chromosomes. #3 #2 #4 #1 Homologous Pairs Before Segregation Pink: the one received from “mom” Blue: the one received from “dad”. Homologous Pairs After Segregation Note That I changed the color to black for all 4 pairs. What we need to understand is that the pairs separate from their “match” and move to the opposite side of the cell before it divides. Law of Independent Assortment 1. When the homologous pairs separate, there is no way to predict which resulting egg or sperm they will end up in. 2. This really comes down to chance, probability and the “luck of the draw”. What Does Independent Assortment Look Like? Here is one example of how it might look. We will use numbers to represent the chromosome pairs. Pink are from mom, blue were inherited from dad. 11223344 5566778 8 9 9 10 10 11 11 12 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 Or it could look like this: 11223344 5566778 8 9 9 10 10 11 11 12 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 11223344 5566778 8 9 9 10 10 11 11 12 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 It’s all based on CHANCE! You are the result of a winning combination!