SAVY 2019: Session 5, Day 2 – Dabbling with DNA (Rising 3rd/4th)
After starting the day with a GYKY activity of four corners we reviewed what we had learned yesterday about cells and DNA. It was then time for Mendelian genetics. We examined pea plants and brainstormed on the various traits that pea plants exhibit and considered the traits that Mendel studied. We learned about genotype and phenotype, dominant and recessive traits, homozygous and heterozygous, genes and heredity. It was a lot of information and the children did a pretty good job of concentrating and were sincerely curious about the information. Genetics is a fascinating topic and the students demonstrated their enthusiasm for the subject.
In the late morning and afternoon, we studied Punnett squares and calculated the probabilities of different outcomes. This was challenging and something that most students don’t tackle until they are much older, but the students quickly picked up on the connection between a fraction and a percent. This is the first time I have taught this grade level and I am impressed with what they know! We then examined a pedigree – family tree – and each student sketched out their family tree. We looked at pedigrees for several traits and the students figured out that the tree is informative for determining genotypes and probabilities of outcomes. We finished the day using a kit called Crazy Traits in which each group starts with identical parents, each heterozygous for 13 traits. They flip coins to determine which alleles each parent passes on to the child. They then construct the crazy creature and see that even though the parents were identical, each child was different. It’s amazing how heredity works! It was a busy day and tomorrow will be as well when we start our study of evolution, natural selection, and artificial selection.