12/12

On Monday, students worked in groups to complete Punnett squares. On Tuesday, students participated in the "Face Lab." In this lab, students had to play the role of parents and flip coins in order to determine which traits would be passed on to their "child." This lab reinforced how alleles are passed from parents to offspring and how probability (in our case, flipping a coin) plays a major role in genetics. Students had to use the results from their coin flips to draw what their "child" would look like. I must say, we had some VERY interesting looking children as a result of this lab! We began examining X-linked traits this week as well. We discussed how certain traits were located on the X chromosome and that females have XX sex chromosomes, while males have XY sex chromosomes. We used this knowledge to learn how to do X-linked Punnett squares. We spent time practicing these Punnett squares in small groups on Friday, and students really seem to be getting the hang of it! Next week we will discuss genetic disorders and take our Chapter 5 test on Thursday!

12/4

This week, students were introduced to the basic principles of heredity and genetics. We looked into Gregor Mendel's scientific investigations with pea plants and did a "pollination" activity to see if our results matched up with his. Each students had the chance to observe their physical characteristics and those of our classmates in order to determine whether we had more dominant or recessive traits. Out of the 10 traits that we observed, we found that this year's 7th graders exhibit an equal number of dominant and recessive traits. We also began using Punnett squares to determine all possible outcomes of a cross between two organisms. We will continue our work with Punnett squares next week and we will begin to examine X-linked traits.