Lesson 1
Objectives:
Students will begin with a brainstorming session where they will write what they know about microorganisms, what questions they have about microorganisms, and what they have learned about microorganisms. This KWL chart will be kept in their interactive notebook, as well as displayed in the classroom. K stands for what students KNOW, the W stands for what students WANT to find out, and the L stands for what they have LEARNED after being taught the subject matter. As new information is given through hands-on activities, such as growing microbial mats in the classroom, students will continuously add what they know and generate additional questions.
Materials: (for each student)
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•Green-colored spiral notebook
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•Scissors
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•Glue stick
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•Colored construction paper cut 6x2 inches
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•Colored pencils
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•KWL chart
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•Internet access
Materials: (for the class)
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•Chart paper
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•Colored markers
Lesson 2 (Adapted from The Microbial World: Winogradsky column: perpetual life in a tube)
Objective:
Students will build a Winogradsky column in the classroom in order to develop a keen sense of a, less-than-five millimeter, ecosystem that exists and gain an appreciation of the oldest ecosystem on Earth. This will be an ongoing investigation starting in early fall and continue throughout the school year since it takes from 2 to 3 months of incubation in order for different types of microorganisms to grow.
Materials:
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1.
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Tall glasses or plastic tubes (30cm long, >5 cm wide) keep columns small to avoid too much hydrogen sulfide production/build up.
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2.
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Pond mud
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3.
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Shredded newspaper or hay (for cellulose)
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4.
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Ground egg shells and yolk
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5.
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Pond water
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Procedure:
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1.
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Fill tube or glass one third full of pond mud (omitting sticks, debris and air bubbles). Mud is supplemented with ~ 0.25% w/w calcium carbonate and ~ 0.50% w/w calcium sulfate or sodium sulfate--these will be converted to hydrogen sulfide by any sulfate reducers present
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2.
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Mix together the shredded newspaper or hay along with the ground egg shell and yolk.
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3.
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Add an additional layer of pond mud without the supplement (as noted in step one). This brings the column to two thirds full.
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4.
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Add pond water to fill the tube and to saturate the mud.
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5.
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Seal the column loosely and periodically add more pond water to adjust for evaporation.
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6.
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Place in natural sunlight to incubate over several months.
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Lesson 3
Objective:
Students will gain an understanding of the biogeochemical processes in microbial mats by identifying the producers, consumers, and decomposers of the microbial mats. By defining the terms, producers, consumers, and decomposers with respect to the chemical processes/reactions they are involved in, students will label a diagram of a microbial mat with these terms.
Materials:
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•Diagram of a microbial mat community
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•Three cards with pictures on one side and definitions on the other of producers, consumers, and decomposers
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•Unlabeled diagram of microbial mats (See Appendix)
Procedure:
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1.
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There will be three centers set up labeled producers, consumers, and decomposers.
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2.
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Students will have distributed unlabeled diagram of microbial mats.
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3.
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Students will rotate around to the stations drawing pictures of the microorganism or write a chemical reaction in the correct layer of the microbial mat diagram.
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4.
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Students will get into a group of four to compare notes by having a Socratic seminar.
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Lesson 4 (Adapted from Interactive Biogeochemical Cycle by Robin Bucaria, Dartmouth Middle School
Dr. Brad Bebout, NASA Ames Research Center)
Objective:
Students will investigate three cycles in microbial mats, the oxygen, carbon, and sulfur cycle by playing the cycle game.
Materials:
Cards labeled and laminated with the names and pictures of the microorganisms that exist within a microbial mat: Diatom; Cyanobacteria: Gloecapsa, Oscillatoria, Spirulina, Unicellular Cyanobacteria, Phormidium, Microcoleus; Aerobic Heterotrophs; Fermenters; Sulfate Reducers; Colorless Sulfur Bacteria; Purple Sulfur Bacteria; Methanogens
Procedure:
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1.
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Place cards around the room and have four copies of each.
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2.
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Divide class into seven groups.
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3.
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Students will start at designated parts of the room and will take the card at the station.
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4.
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Student will read card and follow the instructions and move to the next station that the card instructs them to go to.
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5.
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After all students have moved through all seven stations, students will write about what they learned about the three cycles of the microbial mat.
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