Microbial Life > Resources for K-12 Teachers and Students > Living in an Alkaline Environment > For Teachers

Living in an Alkaline Environment

Activity at a Glance


Living in an Alkaline Environment is a three-part activity. Part One and Part Two are hands-on applications, and Part Three is an inquiry-based WebQuest. They may be incorporated into your curriculum as a complete unit or as stand alone activities. The entire activity is available in Microbial Life and may be downloaded in the form of a Word (Microsoft Word 124kB Apr29 05) document. The Word document can be modified to specifically fit your needs. Use the left-hand navigation to access the WebQuest and Student Pages.
Student using proper safety procedures in the laboratory, Mono Lake, Dunaliella, Frontonia, Artemia monica, California Gull
From left to right: Mia Patterson uses proper safety procedures as she begins the activity (Image credit: David J. Patterson); Mono Lake (Image credit: Brett Leigh Dicks/microscope ); Dunaliella (Image Credit: David J. Patterson/microscope ); Frontonia (Image credit: David J. Patterson/microscope ); Artemia monica (Image credit: David J. Patterson/microscope ); California Gull (Image credit: National Park Service staff photo)


Purpose Overview Key Concepts Key Skills Time Materials 5-8 Standards 9-12 Standards

Purpose


Part 1: To show many ways in which Mono Lake water and distilled water are different

Part 2: To demonstrate that the survival of common soil bacteria declines as pH increases

Part 3: To examine the behaviors, adaptations, energy transfer, and diversity of organisms in an alkaliphilic habitatBack to Top


Overview

Part 1: Students compare distilled water with simulated Mono Lake water by conducting eight tests at four activity stations. They also observe two teacher demonstrations. They record the results of this testing on a student handout. They see that Mono Lake's high pH and high salt and mineral content make its water considerably different than distilled water. They discuss how Mono Lake's extreme chemistry might stress organisms adapted for a typical pond, lake, or river and answer four questions on the student handout.

Part 2: Students use soil bacteria from the local environment to inoculate four agar plates with pH ranging from 7 to 10. After 24-48 hours, they count the number of colonies on the plates and create a graph comparing the number of colonies and the pH. They see that survival declines as pH increases. They then visit the Marine Biological Laboratory's online microscope to see that, in fact, there are organisms adapted to living in Mono Lake's extreme environment. They brainstorm a list of adaptations that organisms living in such an environment might have and answer four questions on the student handout.

Part 3: Students do a WebQuest and see that organisms in alkaliphilic habitats have unique and sometimes complex food webs, behaviors, adaptations, and overall diversity.Back to Top


Key Concepts


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Key Skills


Part 1: Comparing different substances; Measuring pH; Measuring specific gravity

Part 2: Inoculating agar plates; Counting colony abundance on an agar plate; Creating a graph

Part 3: Conducting a WebQuest; Synthesizing information from a WebQuest Back to Top


Time


(One day is considered to be a 50-minute class)

Part 1: Day 1: Visit the activity stations; Day 2: Conduct the demonstrations & discussion

Part 2: Day 1: Inoculate plates; Day 2: Brief observation; Day 3: Final observation & graphing

Part 3: Day 1: Begin WebQuest; Day 2 - 3: Finish WebQuestBack to Top


Materials


Part 1: Student sheets, Distilled water; Table salt; Baking soda, Epsom salt; Borax; Detergent containing phosphate (e.g., Spic & Span); Sodium hydroxide (Sodium hydroxide is readily and inexpensively available as lye in hardware and grocery stores); Dropper bottles; pH meters, papers, or strips; Cooking oil; Wax paper; 100 ml, 500 ml and 1000 ml beakers; Specific gravity hydrometer or rods/spheres that indicate density by floating or sinking; 2 dishpans; Dozen eggs; 4 teaspoons; Paper towels or sponge; Heat source (e.g., Bunsen burner, candle, alcohol burner); 2 spoons with insulated handles (or oven mitt); Dropper bottle of vinegar; microscope whose image can be displayed on a computer or projection screen; Microscope slide; Cover slip; Tissue or other absorptive material; Cellular stain (if necessary for clarity)

Part 2: Student sheets; Soil samples; 2 Liter Flask, 40-50 Petri dishes; Hot plate w/ stirrer and stir bar; Aluminum Foil; pH strips, litmus paper, or pH meter; 40 g tryptic soy agar (powder, pre-made, or Easy-Gel), 0.1 M Hydrochloric Acid; 0.1 M Sodium hydroxide

Part 3: Computer lab with internet connectionBack to Top


National Science Education Standards, Grades 5-8


Grades 5-8: Physical Science-Content Standard B, Properties and Changes of Properties in Matter

Grades 5-8: Life Science-Content Standard C, Structure and Function in Living Systems

Grades 5-8: Life Science-Content Standard C, Regulation and Behavior

Grades 5-8: Life Science-Content Standard C, Diversity and Adaptations of Organisms

Grades 5-8: Earth And Space Science-Content Standard D, Structure of the Earth System

Grades 5-8: Science In Personal And Social Perspectives-Content Standard F, Natural Hazards

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National Science Education Standards, Grades 9-12


Grades 9-12: Physical Science-Content Standard B, Chemical Reactions

Grades 9-12: Life Science-Content Standard C, The Cell

Grades 9-12: Life Science-Content Standard C, Biological Evolution

Grades 9-12: Life Science-Content Standard C, Matter, Energy, and Organization in Living Systems

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