Clockwise from top left: alga, rotifer, diatom, soil amebas with cysts

Background:
Soil is filled with many microbes including: fungi, protozoans, algae, and bacteria. Soil amebas are smaller and slower moving than the amebas found in pond water. Amebas eat bacteria in the soil.

Purpose:
In this activity we will try to separate soil amebas from different soil samples and observe them under the microscope.

Method:
Various soil samples were collected. These samples include: 1-muck from the Constitution Marsh on the Hudson River, 2-horse manure mixed with dirt, 3-soil from a sidewalk crack, 4-rotten wood particles from the forest near Constitution Marsh, and 5-potting soil.

We took five agar/agar plates and made a quarter size ring streak of Enterobacter aerogenes as a food source. Next, we placed a small sample of soil at the center of the ring. We let the plates incubate overnight at 37 degree Celsius.

We hoped that the soil amebas would crawl out of the soil toward the bacterial food source where we could easily observe them seperate from other organisms in the soil samples.

Results:
When we looked at the petri dishes under the microscope we found various organisms mostly very close to the soil sample(some of the organisms are pictured below). We found no amebas in any of the samples however. Dr. Gorell looked at our sample and confirmed our findings, but he pointed out that ameba cysts had formed.

We took one of the plates with cysts and re-smeared the plate with bacteria and went to lunch. Upon returing from lunch, about 90 minutes later, we re-examined the plate and found that ameba had emerged from the cysts.

Appliction to the Classroom:
I think that this activity could be used for my Regent's Biology class. I could use this as a lab activity to demonstrate the ubiquity of microbes. Students could bring in their own samples to examine. We could let the samples sit overnight. Students could look for soil ameba as well as other organisms. It would be like a microbe safari. The petri dishes may be easier for the students to use and examine microbes than slides because the organisms move slower on the agar plates. The plates are also easier to handle and less likely to break.

We also compiled a unit in biodiversity that we will bring back to school and teach our classes.

Unit in Biodiversity:

1. Context and Classroom Environment.
 
I plan to teach this biodiversity unit to my “Science, Technology and Society” classes. These classes
are composed of thirty four students each. These students are seniors at Brooklyn Technical High
School. They are enrolled in a Technology and Liberal Arts major.
 
As Brooklyn Tech students they have come to the school by taking, and scoring well on the
Specialized High School Entrance Exam. I think our students can be described as above average
for New York City public schools. All TLA students have taken Regent’s Biology in ninth grade,
Regent’s Chemistry in tenth grade, and Regent’s Physics in twelvth grade.
 
As TLA majors they have chosen a course of study over their junior and senior years that focuses on
a liberal arts education.
 
I meet with these students for one forty one minute period each day for the fall semester. We meet in a classroom with lecture style seating and movable desks. We are not scheduled to meet
in lab.
 
2. Connection with Curriculum and audience.
 
Since I will be teaching the STS course, I will not use the regents biology “Living Environment”
curriculum. Instead, I will use the “New Standards” curriculum.Some of the science understandings that the unit on biodiversity will touch on include the following:
 
Students produce evidence that demonstrates understanding of:
 
S2d. Interdependence of organisms, such as conservation of matter; cooperation and competition
among organisms in ecosystems; and human effects on the environment.
 
S2e. Matter, energy, and organization in living systems, such as matter and energy flow through
different levels of organization, and environmental constraints.
 
S3b. Geochemical cycles, such as conservation of matter; chemical resources and movement of
matter between chemical reservoirs.
 
S3e. Natural resource management.
 
S4a. Big ideas and unifying concepts, such as order and organization; models, form and function;
change and constancy; and cause and effect.
 
S4b. The designed world, such as the reciprocal relationship between science and technology; the
development of agricultural techniques; and the reasonableness of technological designs.
 
S4c. Health, such as nutrition and exercise; disease and epidimiology; personal and environmental
safety; and resources, environmental stress, and population growth.
 
S4d. Impact of technology, such as consteints and trade-off’s; feedback; benefits and risks; and
problems and solutions.
 
S4e. Impact of science, such as historical and contemporary contributions; and interactions between
science and society.
 
In addition, the student:
 
S5f. Works individually and in teams to collect and share information and ideas.
 
S6d. Acquires information from multiple sources, such as print, the Internet, computer databases,
and experimentation.
 
S7a. Represents data and results in multiple ways such as numbers, tables, and graphs; drawings,
diagrams, and artwork; technical and creative writing; and selects the most effective way to convey
the scientific information.
 
3. Propose inquiry questions and describe an individual or group project you expect to develop.
 
Inquiry Questions:
 
What is biodiversity?
Why is biodiversity important?
What are the threats facing life on earth right now?
What are the ethical issues involved in biodiversity?
What can be done to stem the tide of habitat destruction and species extinction?
 
Projects:
 
Project 1: Give a presentation on the importance of biodiversity. Choose an organism of importance
and do the following:
 
Show a picture of the organism.
Describe its physical characteristics.
Describe its behavior.
Describe the habitat it lives in.
Describe the range of this organism.
Describe the ecological niche of this organism (the role this organism plays in the ecosystem).
Describe the organisms importance to humans? (Do humans depend directly on this organism for
food, clothing, medicine, or shelter? Do humans depend indirectly on this organism? (Is it a food for
organisms that humans do use?))
Is this organism extinct, endangered, or threatened?
What are the future prospects for this organism?
 
Project 2: Give a presentation on how humans are impacting on biodiversity? Choose a specific area
and do a case study of a specific “hot spot”. Types of human impact on biodiversity include, but are
not limited to: habitat loss, habitat degradation, agricultural practices, introduction of exotic species,
overhunting and overharvesting.
 
Choose a particular “hot spot” (The tropical rain forests of the Amazon basin for example).
Show on a map, the location of the area.
Describe the environment (What is the geography of the region? What is the climate like?
What kind of organisms are present?
What is the economic value of this area to humans?
How are humans using this area?
What is the human impact on this area?
 
Project 3: The impact of consumer culture: Choose a particular product that you might buy (Coke,
or Con Edison Electricity for example).
 
Describe the product
Document how the manufacture of this product impacts the environment.
What kind of natural resources are used?
How are these resources harvested?
Are the resources environmentally sustainable?
Document how the use of the product impacts the environment.
 
4. Develop a schedule and describe the weekly topics and methods you’ll use to address the topic.
 
Week 1: What is biodiversity?
 
Week 2: Why is Biodiversity important?
 
Week 3: What are the threats facing life on earth right now?
 
Week 4: What are the ethical issues involved in biodiversity?
 
Week 5: What can be done to stem the tide of habitat destruction and species extinction?
 
 
5. Develop a list of resources to use with the students:
 
Bibliography:
 
Wilson, Edward O. Biodiversity. Washington, DC: National Academy Press, 1988.
 
This book calls attention to a most urgent global problem: the rapidly accelerating loss of plant and
animal species to increasing human population pressure and the demands of economic development.
Biodiversity creates a systematic framework for analyzing the problem and searching for possible
solutions. Amazon.com.
 
Safina, Carl. Song for the Blue Ocean: Encounters Along the World’s Coasts and Beneath the Seas.
New York, NY: Henry Holt & Company, 1997.
 
The oceans of the world rank foremost among humankind's last great frontiers, and their
climatological and ecological workings remain mysterious to all but specialists. In this lively,
well-written survey, marine scientist Carl Safina encourages readers to take a wider interest in the
oceans, especially because so much of that great blue expanse is now threatened by human
progress. Safina notes, for example, that the North Atlantic's tuna population has fallen by more than
90 percent in just the last few decades. It has gone the way of cod and herring and pilot whales
thanks to a combination of changing global temperatures, overfishing, pollution, inland watershed and
delta destruction, and other causes--many of them attributable to human activities. Even now, he
notes, many Pacific fishing fleets use cyanide to catch fish, a process that destroys sensitive marine
ecosystems. Safina's tour of the world's waters may inspire readers to press for changes in the way
that fish is brought to their tables, and to take a more careful look at the natural processes that
govern this watery planet.Amazon.com.
 
Quammen, David. The Song of the Dodo: Island Biogeography in an age of Extinctions. New York,
NY: Scribner.
 
A work of scientific journalism which explains the worldwide ecosystem decay which is at the root
of countless species' extinction and which will continue to wipe out species as human activity carves
the wilderness into ever-increasing island-like fragments. Annotation c. by Book News, Inc.,
Portland, Or.
 
Baskin, Yvonne. The Work of Nature: How the Diversity of Life Sustains Us. Washington, DC:
Island Press, 1997.
 
In The Work of Nature, noted science writer Yvonne Baskin examines the threats posed to humans
by the loss of biodiversity. She summarizes and explains key findings from the ecological sciences,
highlighting examples from around the world where shifts in species have affected the provision of
clean air, pure water, fertile soils, lush landscapes, and stable natural communities. Distilling and
bringing to life the work of the world's leading ecologists, The Work of Nature is the first book of its
kind to clearly explain the practical consequences of declining biodiversity on ecosystem health and
functioning. Donna Seaman. Copyright© 1997, American Library Association.
 
Wilson, Edward O. The Diversity of Life. Cambridge, MA: Belknap Press of Harvard University
Press, 1992.
 
Wilson (entomology, Harvard U., and winner of two Pulitzer Prizes) conducts a tour through time,
tracing the processes that create new species in bursts of adaptive radiation. He identifies crises in
ecosystems around the globe and discusses diverse examples, making a plea for specific actions that
will enhance rather than diminish the quality of life on earth. Includes b&w illustrations throughout, 16
pages of color plates, and a glossary. Annotation copyright Book News, Inc. Portland, Or.
 
Koebner, Linda & Sokolow, Jane E. S. Scientists on Biodiversity. New York, NY: American
Museum of Natural History, 1998.
 
A collection of essays by a variety of scientists from the American Museum of Natural History and
others. These essays focus on the importance of biodiversity; what we are loosing; and solutions to
the problem of loss of biodiversity. Also contains profiles of scientists. Essays are short: three pages
on average, and could be used to motivate students or provide information.
 
Natural History Magazine. June, 6th 1998.
 
This issue of Natural History contains a special section on evolution and biodiversity, and the making
of the museum’s “Hall of Biodiversity”.
 
The New York Times. Biodiversity Issue (June ’98?).
 
Web Resources:
 
American Museum of Natural History
www.amnh.org
 
Center for Biodiversity and Conservation
Research.amnh.org/biodiversity/index.html
 
World Resources Institute­-Biodiversity Resources
www.wri.org/biodiv/biolinks.html
 
Video:
 
Biodiversity: Exploring the Web of Life
 
Life in the Balance, 1997. American Museum of Natural History.

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