Got Lactase? - Understanding Genetic Inheiritance

Our lesson is based on two HHMI genetics labs that we have integrated with the genetic data provided by a 23andme test to introduce our Lucile Packard Hospital School students to the ideas of genetic variation and genetic inheritance. 

We will spend Day 1 discussing pedigrees and how traits can be inherited from parent to child. We will start by watching the Where Do Your Genes Come From? video from 23andme. We will follow this HHMI Pedigree Lab. Following the lab discussions, we will have students create pedigrees of their family members hair color using a simplified inheritance where dark hair is dominant (B) and light hair is recessive (b) and introducing the concept of a Punnet square. We will introduce the concept of a punnett square and determine whether or not two muggle parents could have a wizard baby (assuming muggle is dominant to wizard). To conclude, we will use a simplified view of hair color inheritance (dominant dark hair, recessive light hair) and have the students determine the genotypes for their immediate family based on the phenotypes. I will show an example walking through my immediate family: my brother has light hair, so he must be bb; I have dark hair, so I can be BB or Bb; Knowing my mom has light hair, she must be bb; Knowing I get one allele from my mom, I must be Bb; Without knowing my dad's haircolor, we can determine he must have dark hair because I got a B from him and my brother got a b from. Students can do similar anylsis to figure out as much about their family as possible (note: families with all dark hair are difficult to elucidate with certainty). 

We will spend Day 2 discussing lactose intolerance and testing "patient" samples to determine if they are lactase persistant or lactase non-persistant. We will begin by reviewing simple DNA --> RNA --> protein ideas and show the 23andme What is a SNP? video. We will follow this HHMI Lactase Lab. We will also discuss the genetic variation that leads to lactose intolerance and have the students predict the instructors lactose intolerance status. We will then discuss genome sequencing and genotyping and check the instructors 23andme raw data for lactose intolerance.  

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