Unit 5 - Diversity of Life

Monday or February 13, 2017 C.E.: 

We have just cleared our latest unit, the diversity of life. I feel like this unit binds what we have learned together and will serve as a base as we move on. We began the unit by studying the classification of organisms everywhere from domains to species. We examined the evolution of organisms and the history of life. Combining what we know from Darwin (natural selection) and Mendel (genetics) we were able to learn about evolution and speciation. Through these concepts I was able to learn about the different ways species are created and how evolution works. We learned about how the fossil record provides scientists with the information they need to conclude and prove evolution.  We also learned that because of DNA, we know that all life-forms come from a common ancestor. In addition to this, we were also taught the concept of artificial selection and adaptations.

The latter half of the unit was spent on viruses and bacteria. I learned that viruses are actually not considered living! I never knew that. Viruses reproduce using the Lytic and Lysogenic cycles. A virus will attach to a host cell and inject its DNA into its host cell. The genetic material will code for virus particles which will begin to be created by the cell. The viruses are assembled and leave the cell, rupturing it through lysis.

The Lytic/Lysogenic Cycle

In order to reinforce what we learned in the unit, we took part in a few great labs. In one, we simulated the spread of viruses, in which one person had a test tube with an acid and, through exchanging drops, infected half the class once we revealed who had the acid. We also underwent two amazing labs about microorganisms. In the first we cultivated soil bacteria in petri dishes with four pieces of paper in each dish. Each piece of paper was saturated in a disinfectant and one with water. We then compared the growth of the bacteria. In another lab we incubated bacteria swabbed from a variety of areas such as a computer keyboard, water fountain, the floor, and a phone. The petri dishes containing keyboard bacteria and locker handle bacteria looked the worst.

Biology is becoming more and more fun the farther we are going into it. In the next unit about plants, we will begin our first dissections! In the recent test, I did not score as high as I would have liked, but I will reexamine my study habits and improve this for next time. I can't wait for the units to come. They are just becoming more exciting as they move on.