I was at a district-wide high school biology teacher meeting this morning during periods 1-3. Below is the lesson plan my substitute shared with the students:
Yesterday we learned about how the construction of a causeway across the Great Salt Lake dramatically affected the ecosystem of the Great Salt Lake.
Entry Task: In your lab notebook, describe how the causeway resulted in the north arm of the lake appearing purple compared with the blue south arm. You have 5 minutes.
Group work: Working with your extreme environment group, your job is to solve the problem of the GSL railroad causeway. Your team must devise a solution to undo the ecological changes of the causeway on the ecosystem of the Great Salt Lake. Your group’s report must include the following:
- A model of how altering the causeway will affect the populations of each of the 8 GSL organisms.
- Application of the concepts of osmosis, diffusion, and active transport in your model.
- Initial ideas on how GSL organisms will be immediately affected by a change in the salinity of the GSL upon changing of the causeway. You must include a discussion of water and/or salt moving across cell membranes for full credit.
- Research! Slides 15-20 from yesterday’s lesson (on the class website) may be a useful starting point. Be sure to cite any references used when making claims about GSL salinity (before and after causeway changes) and any references used to learn which organisms can survive at the salinities found in the GSL after the causeway is removed. Please use electronic resources appropriately.
- Your analysis should include a written discussion of the risks and benefits of altering the causeway, both to the railroad and to the organisms that live in the Lake.
Exit Ticket: Turn in group work with names of all students who actively engaged in the work for the entire class period.
We kicked off our first big lesson of the unit with a case study of the Great Salt Lake. Back in the 1950s, a causeway was built across the Great Salt Lake, phyiscally separating the lake into two arms (the North and South Arms). As a result, the ecosystem of the North Arm of the lake is quite different from the South Arm. In the case study, students learned how various biotic and abiotic factors contribute to the appearance of the lake. Within the case study, the concept of osmosis is presented, and students were assigned as homework to find the biology definitions for osmosis, diffusion, and active transport. Students turned in the case study worksheet at the end of class.
Tomorrow, students will apply their understanding of the causeway, and the vocabulary words they learned as homework, to work in groups to devise a solution to the ecological changes caused by the causeway. I will be in a meeting during periods 1-3, and students should work efficiently with their extreme environment groups to complete the work.
Curious why the Great Salt Lake is so salty? Check out this video clip from the Travel Channel show Off Limits (starting at about 1:30). http://www.travelchannel.com/video/the-sea-salt-of-utah
Today we turned our attention to the Great Salt Lake. We learned about the organisms that live in the lake, with students taking notes on a worksheet while we worked through a Power Point slide deck. Students learned that in a food web, organisms are drawn as nodes and the edges represent energy. The direction of the edge indicates the predator/prey relationship, with the arrow pointing away from the prey and toward the predator. Students then used the information from the slide deck to construct a food web on the initial model worksheet. Students had a lot of questions about using the initial model, and it’s important to keep in mind that the model of our understanding of the Great Salt Lake ecosystem will develop over time. Scientists often develop models with incomplete data sets and then use the gaps in their understanding to devise and test hypotheses. As scientists in training, we will also learn to work with incomplete data and we will learn to keep track of our questions and devise strategies for filling in the gaps in our knowledge.
Updated 9/30/14: We completed the initial model today, with students using scientific reasoning to assign units of energy moving through their food webs. Students turned in both the Power Point worksheet as well as the initial model worksheet at the end of class.
In lesson 10, we continued with our study of osmosis, focusing on the extreme environment of the Great Salt Lake. Students learned that a railroad causeway was built across the lake more than 60 years ago, physically separating the lake into two sides. Only the south side of the lake receives a continuous supply of freshwater, causing the salinity of the south side to be much lower than the north side. As a result, the ecosystem of the south side of the lake is much more robust than the north side which is inhabited primarily be halobacteria. Considered extremophiles because of their unique ability to live in extremely salty water, halobacteria are present in such abundance that they color the water in the north side of the lake purple (because of the rhodopsin protein they produce). As evidence of their learning, students completed a case study worksheet and hypothesized what might happen to the existing Great Salt Lake ecosystem if the causeway were removed.