Skip to main content

Summer SAVY, Session 3 Day 4, Dabbling with DNA (Schott) (3rd – 4th)

Posted by on Thursday, June 27, 2024 in blog, SAVY.

Good evening!  Today, the Dabbling with DNA class started by completing our family trees.  They sketched their tree on a small poster board and we put them on display.  They are lovely.  Next, we completed our studies of artificial selection with a dog breeding activity.  The students were given the task of breeding a dog for a particular job and had to choose among six breeds with variable forms of traits.  Some were meek; some were mild; some had greater endurance than others; some were louder or had better hearing, etc.  Their pair of dogs had three pups, and the form of the trait that each pup inherited was determined by a coin flip.  They gained an appreciation for the randomness of heredity.  We finished the morning talking about the structure of DNA and the people involved in figuring this out: Watson, Crick, Franklin, and Wilkins.  This led to a brief digression about the Nobel Prize and why Watson, Crick, and Wilkins won the prize, but Franklin didn’t.  They didn’t think that was fair.  Next, they built a model of DNA with Twizzlers, mini-marshmallows, and toothpicks. You’ll have to ask your scientist how they built it and what the different parts symbolize within the DNA structure!

In the afternoon, we talked about the idea of the “DNA sequence”: what that is and how it is used to create a DNA profile (DNA fingerprint).  I stressed to them that while there are differences between us much of our DNA is very similar, and we share the same genes.  However, we have different forms of those genes (different alleles).  They created a DNA profile for a hypothetical crime, the stealing of a lollypop, and figured out whose DNA was found on the lollypop.  This involved a brief discussion of restriction enzymes and gel electrophoresis.  Heads up, when we were looking at examples of DNA profiles (gels) paternity analysis was mentioned as a use for DNA profiling, in addition to crime scene analysis and determining ancestry.  They asked what that was, and I explained that sometimes you have to figure out who is the dad.  They thought this was silly because of course you know who dad is.  If they ask you about it, that’s why. 

We finished the day with genetically modified organisms (GMOs), what they are, how they are created, and how they are different from traditional breeding (artificial selection).  I introduced the GMO project, and they began choosing and investigating a particular GMO.  Tomorrow, they will do a lot of research, create a poster about their GMO, and present it to the class.  Some of the students are nervous about presenting, so maybe tonight, you can give them a pep talk. You may want to ask your child what they understand about GMOs and how they are different from what is created with artificial selection.  Why is it that GMO corn has a little bit of bacterial DNA in it?  Ask them about the DNA sequence and what makes it different in each of us.  Hopefully, they can tell you that it’s the sequence of A, T, C, and G (the nucleotides) that makes it different.