We began the day by revisiting the grass/cow/hamburger slide from yesterday, Students were challenged to apply their understanding of the food web by figuring out how much grass a cow has to eat to produce a hamburger. Understanding that grass is at the bottom of the food chain (like halobacteria in the Great Salt Lake), and recognizing that cows eat grass (like brine shrimp eat halobacteria), students reasoned that it would take 10 times as much mass in grass to produce one hamburger. If a hamburger has a mass of 100 grams, then a cow would have to eat 1000 grams of grass to produce the hamburger. Several students wondered how much land is required to produce 1000 grams of grass, and I encourage all of my students to research that question for extra credit!
We continued our discussion of the food web game by analyzing group results, assembling a table of class results, and calculating the average number of organisms at each level of the food chain. Students observed the 10-fold decrease in organism mass as we move up the food chain, and we connected the concept of biomass with energy. The results for each class period are reported at the end of the slide deck. We also discussed the variables involved in the food web game activity, with students identifying distance from the seed-trading space, number of students per group, and the efficiency with which groups worked as key variables contributing to how many higher-level organisms a group obtained.
After the slide deck and discussion, students worked in groups to complete the back side of the worksheet from yesterday. Students learned that while the amount of matter in a system stays constant, the amount of energy in a given level decreases as we move up the food chain. This is not always obvious, especially because organisms at the bottom of the food chain tend to be very small (yet great in number).
Today we modeled energy transfer through a food chain. We worked through a brief slide deck and added the words food chain, matter, and energy to our vocabulary list and began thinking about what happens to matter (grass) eaten by an organism (a cow) that does not become food for the consumer of the cow (us, when we eat a hamburger). We then modeled energy transfer through a selection of Great Salt Lake organisms present in a food chain. Using 4 different types of beans, we played the Food Web Game and learned how only 10% of the energy in one level of a food chain is passed along to the next level. The game took us to the end of the period, so tomorrow we will share group data, calculate class averages, and complete page 2 of the Food Web Game worksheet.
With short periods today, students selected unit-articles to read from our vast collection of Scientific American magazines. Students wrote summary paragraphs describing each page of the article they read, with paragraphs consisting of the main ideas presented on the page, three things the student learned from the reading, and a list of vocabulary words for follow-up. Have a great weekend!
Today we focused on 8 factors that are commonly found in environments we consider to be extreme. Students began the lesson with an introduction to the bell curve and an brief explanation of the mean and standard deviation. Students then silently brainstormed three examples of things they consider extreme, with an explanation about why. During our share out, students were encouraged to consider whether the idea of “extreme” is relative. For example, we might regard a skydiver as someone who participates in an extreme sport. However, the skydiver might share a different perspective. Similarly, we might classify a polar bear as an extremophile, given it’s ability to live in extremely cold temperatures. However, the polar bear, being unable to live comfortably away from the south pole, might consider organisms living in warmer climates as extremophiles. After learning about the 8 factors and exploring representative locations and organisms at those locations (see Power Point slides), students completed their extreme environments critter diagrams from yesterday.
At the beginning of class yesterday, students were faced with the following scenario: You are an extreme environment engineer. Pick your next work assignment. The options were: The Ocean Floor, Olympus Mons (tallest known volcano in the solar system, located on Mars), Antarctica, and The Moon. Today, students were grouped based on their work site preference. Working in groups of 3 or 4, students then were assigned the extremophiles reading packet. Each group member was assigned a roles (slide 1), with the role rotating after each paragraph was read. The roles were: Reader, Paraphraser #1, Paraphraser #2, and Recorder. The Reader was responsible for reading the paragraph out loud to the group. The Recorder highlighted words that were challenging for the Reader or needed to be defined for comprehension. Paraphraser #1 was responsible for paraphrasing the main ideas they heard from the Reader. Paraphraser #2 paraphrased what they heard from Paraphraser #1, further distilling the key points down to a single sentence or two. Ultimately, those main points served as discussion points for answering the questions on the worksheet. The exercise served many learning purposes. Students practiced reading challenging scientific words and were supported by their group members who might be more familiar with the word or who could help the group find out the correct pronunciation and meaning. Students also practiced listening and paraphrasing, applying those skills to answer specific comprehension questions about extremophiles. Many students were able to complete the reading and turn it in at the end of class. Students needing extra time should complete the worksheet as homework and turn it in at the beginning of class tomorrow. At the end of the class period, students drew critter diagrams (slide 2) in their lab notebooks and filled out the leg corresponding to their chosen extreme environment. The legs represent extreme conditions encountered by life either currently living, or wishing to live, in the group’s extreme environment. Groups will share out their legs of the critter diagram tomorrow.