MICROBES AND THE NITROGEN CYCLE
Megen Groski Ross/Woodward School, New Haven, CT
([email protected])
Ruth A. Gyure (mentor), Western CT State University ([email protected])
SAMPLE PRE AND POST TEST
QUESTIONS:
INTRODUCTION:
This project addresses scientific method of
inquiry, and the role of microbes in
ecosystems (especially the nitrogen cycle.
1. What are bacteria?
a. multiple-cell animals
c. infections
2. What do bacteria in our soils and waterways do to help our
environment?
a. they serve as food for other organisms
b. they decompose dead organisms and animal wastes into
chemical elements
c. Once ingested, they can protect animals from transmitted
diseases.
d. can protect plants from diseases.
PROJECT GOALS:
•BETTER METHODS for growing and using micro-organisms
at the middle school level (some approaches work much
better than others)
•An emphasis on QUANTITATIVE methods of working with
microbes and chemical aspects of the cycles, using counting,
proportions,
measurements, graphing and interpretation of graphs and
number sets.
•UNDERSTANDING the prevalence and diversity of microbes
and their beneficial role in ecosystems and in the body.
•Ability to DESIGN AND CARRY OUT EXPERIMENTS to test
the role of microbes in assisting plants to obtain nitrogen from
the air.
b. single-cell organisms
d. vitamins
www.science.uwaterloo.ca/~tcharles/rhizobiu
m.html
•APPLICATION to real life issues such as farming, sewage
treatment, industry, pollution.
DISCUSSION:
Students were excited about this hands on learning
experience. They enjoyed collecting data and made several
comments about “feeling like a scientist”.
I had hoped that they would gain an understanding of the
3. What do helpful bacteria do for humans and animals?
nitrogen cycle as well as learn about conducting an
a. They help digest food and destroy harmful organisms in the
experiment. I think that parts of the Nitrogen cycle got lost
intestines
along the way but they truly loved gathering data and then
b. Intestinal bacteria help the body absorb vitamins
interpreting it.
c. They ward off warts
After completing this project I feel that my students have not
only met the intended goals but are also confident in
completing any scientific task put in from of them. They
particularly enjoyed interpreting data and explaining their
thoughts to me about the how’s and why’s of the experiment.
METHODS:
•Students posed questions about the growth of pea plants
•with and without nitrogen fertilizer, and helpful bacterial
inoculum (root-colonizing Rhizobium).
•Hypotheses about which plants would grow better were
developed.
•Experiments were set up using 3 of each type of bag and
3 to 4 seeds in each bag.
•For several weeks students watched the seeds recording
their observations. After a month students took
measurements from each bag to determine which
treatment grew the largest plant.
•Students recorded their data in charts and constructed
graphs to help reach their conclusions.
REFERENCES
•Classroom Aquaponics: Exploring Nitrogen Cycling in a Closed System
Teacher’s Guide:
csip.cornell.edu/Curriculum_Resources/CEIRP/Aquaponics.htm
•Teaching Ecology Newsletter
www.britishecologicalsociety.org/articles/education/resources
•Vision Learning www.visionlearning.com
•Wiggins, G. and McTighe, J. (2005). Understanding by Design,
Expanded Second Edition. Alexandria, VA: Association for Supervision
and Curriculum Development.
•Windows to the Universe: www.windows.ucar.edu/tour/link