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Warmup 10/24/16 If one parent is TT and the other tt, what chance is it that the kid will have a dominant phenotype? Objective To learn how to calculate genetic possibilities Tonight’s Homework p 117: 6-9 Punnett Squares How do we answer something like our warmup? Scientists have a tool called a “Punnett Square” to help with this. Punnett Squares How do we answer something like our warmup? Scientists have a tool called a “Punnett Square” to help with this. First we draw a grid. Punnett Squares How do we answer something like our warmup? Scientists have a tool called a “Punnett Square” to help with this. First we draw a grid. M Next, we add the Mom’s gametes to the top and the Dad’s to the side. Let’s say Mom is “MM” and Dad is “mm” m m M Punnett Squares How do we answer something like our warmup? Scientists have a tool called a “Punnett Square” to help with this. First we draw a grid. Next, we add the Mom’s gametes to the top and the Dad’s to the side. Let’s say Mom is “MM” and Dad is “mm” Then we can combine gametes to see what results the kid may have. M M m Mm Mm m Mm Mm Punnett Squares In this example, we can see that no matter how things combine, our child with have genes “Mm”. If “M” is dominant, we would say that our child has… 100% chance of having a genotype of “Mm” 100% chance of having a dominant “M” phenotype. M M m Mm Mm m Mm Mm Pedigree Lines So how do we know what the Mom and Dad have for genes? Sometimes it’s just given to us, other times we have to figure it out ourselves. We can figure it out with something called pedigree lines. These tell us what phenotype a parent shows. With enough offspring, this should tell us genotypes. Punnett Squares We’re going to practice with this stuff for a few days. Fill out the Punnett squares below, listing the % chance of each genotype and phenotype. M M m m M M m M M m m M m M M M m m m m Exit Question If one parent is TT and the other tt, what chance is it that the kid will have a dominant phenotype? a) 100% b) 75% c) 50% d) 25% e) 0% f) Not enough information