Over Thanksgiving break, we were all asked to create a family pedigree that included our family’s health history. Thanksgiving was the perfect opportunity to not only catch up with family but to find out a little bit about what health problems our relatives have.
The family pedigree was a start to our new season, Genetics. We used interactive 3 dimensional Z Space desktops to learn about Gregor Mendel’s studies of pea plants. Mendel used pea plants to observe because they have easily distinguishable traits. He was able manipulate the pea plants reproduction by using a paintbrush to cross pollinate the flowers himself. The traits he studied included: tall versus short, purple versus white, and having the peas green or yellow. Through this study, we found out that each parent passed down 1 allele/factor to the offspring, two copies of information are carried in each trait. Mendel’s Law of Segregation supports that the joining of two gametes produces a new plant with two copies of information. Mendel’s Law of Dominance supports that the dominant trait will show through if a dominant allele is present. A recessive trait will only be visible if the organism has a homozygous recessive genotype. Mendel’s Law of Assortment supports that individual alleles must be split up, but can be passed down separately.
After knowing a background of how traits are passed down, we made a paper DNA model. The creation of the DNA model represented DNA replication. The ligase, an enzyme that binds the DNA, was represented by the glue. The scissors that split the two pieces of green paper, represents the enzyme helocase, which splits open and unwinds the DNA. The DNA polymerase adds each nucleotide and was represented by the action of us writing in each letter (A, C, G, and T). We also now understand that DNA is built from bond 5 to 3, but is read from 3 to 5. The repetition of writing and cutting really helped each of us grasp the process of DNA replication.
Genetics has been a season that each of us have been waiting for, and we all have had so much fun so far! Next week, we will be exploring different genetic disorders. I am very excited to continue this season of Genetics!