Spring SAVY 2022 – Dabbling with DNA for 5th/6th Grade (Schott)
The Dabbling with DNA class convened on Saturday February 5th to study DNA and genetics. We started the class with a discussion of variation in us and other species and quantified the differences among us for eye color, ear lobes, tongue rolling, and widow’s peak. We generated bar charts for the different traits and calculated the frequency of each phenotype. The students then filled in Punnett squares and saw the value in using them to calculate the probability of different outcomes. We studied the structure of DNA, built a model out of clay and toothpicks, and figured out how information is embodied in the sequence of bases in DNA. The last activity before lunch was the transcription-translation relay where members of a team transcribed a gene as quickly as possible and the other members of the team then translated the gene. From this activity and our discussion, they learned how the information in DNA is put into action in our cells. It was then time for lunch after a full morning of learning!
The first afternoon activity was extracting DNA from our cheek cells. This is a simple procedure in which they swish salt water around in their mouth, put this solution into a tube, add a soap solution, gently mix, and then carefully add rubbing alcohol. Students learned that the soap breaks up their cheek cells, the salt separates the DNA from associated proteins, and the alcohol causes the DNA to precipitate. It is a simple and safe procedure that allows them to see their DNA. Next, they built Crazy Creatures which demonstrates that when starting with identical heterozygous parents it is virtually impossible to generate offspring that have the same genotype/phenotypes for 14 traits. The final topic was a brief discussion of change over time and a video of the evolution of lactose tolerance in humans.
It was a lot of information for one day! We refreshed some students’ memories on some topics and introduced students to others ideas that they will study in the future. In the meantime, I want to encourage students to keep learning. A good resource for genetics information is the Cold Spring Harbor website (https://dnalc.cshl.edu/). For both genetics and evolution I suggest the Howard Hughes Medical Institute’s BioInteractive website (https://www.biointeractive.org/). HHMI is where you can find the lactose tolerance video. I hope your child enjoyed the class as much as I enjoyed being their teacher!