Transcript Henry W. Euglena vs Roundup

The effects of Roundup on
Euglena gracilis
Henry R. Walther
Grade 10
Pittsburgh Central Catholic
High School
Surface Runoff
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Water that flows over the
land surface and is a
component of the water
cycle
Many substances from
our technology can
dissolve in water and
become a component of
runoff.
This runoff can
contaminate aquatic and
terrestrial ecosystems.
Herbicide
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For a long time, humans
have puzzled over how to
maintain the health of
plants in their selected
environment.
Using technology, we’ve
created various poisons
that reduce the number of
pest plants that can harm
these selected plants:
herbicide.
Unfortunately, these
herbicides will become a
component of runoff.
Relationship
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City dwellers, as well as
rural citizens, often make
use of herbicides.
A fraction of the herbicide
undoubtedly enters local
soils, sewers, and
freshwater systems.
There are numerous
species both macroscopic
and microscopic that could
be adversely affected by
runoff contaminated with
herbicide residues.
Purpose
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The Purpose of this
project was to see
what effect different
concentrations of
Roundup have on a
species of algae,
Euglena gracilis
populations.
Algae
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Are groups of organisms
containing chlorophyll that
carry out photosynthesis
Most are microorganisms,
but some, like seaweed,
are macro-organisms
Produce more oxygen than
any other plants in the
world put together
Make excellent models
because algae are the
bottom of the food chain in
most aquatic ecosystems.
Euglena gracilis
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Are single-celled organisms
In the protist kingdom, because they
make their own food like a plant, and
they eat food like an animal
They eat green algae, which makes
them green
• Chloroplasts, too
They grow on the surface of ponds or
marshes
Have flagella that helps them move;
They sometimes attach to birds’ feet
via mud, and get transported to a new
body of water.
Undergo mitosis, a process of cell
division, to reproduce.
Are hunted by baby fish, water fleas,
mussels, frogs, and salamanders.
Herbicide
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Roundup® Weed & Grass
Killer Ready-To-Use Plus
The active ingredient:
Glyphosate (2%), and
Pelargonic (2%)
Other ingredients (96%)
Glyphosate kills plants by
inhibiting the enzyme 5enolpyruvoyl-shikimate-3phosphate, or EPSP,
synthase which forms the
aromatic amino acids:
phenylalanine, tyrosine and
tryptophan
Effect of Roundup® on plant life
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The main ingredient of Roundup, Glyphosate, can
kill many species of wild plants in concentrations
less than 10 micrograms, making it one of the most
toxic commercial herbicides.
When aerial sprayed at 1200 to 2500 feet Roundup
can kill wild flora up to 300ft from the field it was
sprayed on.
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Roundup has a half life of 47 days to 25 weeks in
soil and a half life of 12 days to 10 weeks in water.
Past studies
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Pesticide Information
Division of Plant Industry
Directorate described the
effect of only Glyphosate on
Euglena gracilis’ cell density
The rate of photosynthesis
was inhibited at
concentrations of 1mg/L
when exposed to
Glyphosate for more than 20
minutes, but stimulated at
concentrations of 50mg /L or
greater.
Null Hypothesis
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Roundup will have no effect on Euglena
gracilis population density outside of
chance
Materials
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A bottle of Roundup®
20 test tubes
Euglena gracilis
Micropipets and Macropipets
Spectrometer
Spring water
Light source (60 watt inc.
bulb)
0.22 Micron syringe filters
Plastic wrap
Beakers and storage bottles
Procedure
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Filled experimental test tubes with the following combinations of
ingredients: 2mL Euglena gracilis + 2.95mL of spring water + .05mL of
100% Roundup stock. This created a concentration of 1% Roundup.
Filled five test tubes with 2mL Euglena gracilis + 2.995mL spring water +
.005mL of 100% Roundup stock. This created a concentration of .1%
Roundup.
Filled five test tubes with 2mL Euglena gracilis + 2.9995mL spring water +
.0005mL of 100% Roundup stock. This created a concentration of .01%
Roundup.
Filled five test tubes with 2mL Euglena gracilis + 3mL spring water. This
created a concentration of 0% Roundup, the control in this experiment.
Covered the top of each test tube with a piece of plastic wrap and mixed
by inversion.
Placed all test tubes in an area of equal lighting (0.5 meter distance) and
temperature (20C).
Measured the absorbance of the algae with a spectrometer at 430nm over
1 week. Readings were recorded on days 1, 3, 5, and 7
effect of roundup on Euglena gracilis populations
absorbance at 430nm
0.7
0%
0.6
0.5
1%
0.4
0.3
0.10%
0.2
0.1
0.01%
0
day 1
day 3
day 5
time elapsed
day 7
% change of Euglena populations
100%
P < .05
80%
60%
0%
40%
1%
20%
0.10%
0%
-20%
-40%
P> .05 P> .05
0.01%
Conclusions
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Based on rigorous statistical analysis I can reject my
null hypothesis that Roundup will have no effect on
Euglena gracilis populations for the 1%
concentration of Roundup.
The same statistical analysis says I can accept my
null hypothesis that Roundup will have no effect on
Euglena gracilis populations for the .1% and .01%
concentration of Roundup.
References
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“Euglena” <http://en.wikipedia.org/wiki/Euglena_gracilis>
(December 17, 2006)
“Glyphosate”
<http://en.wikipedia.org/wiki/Glyphosate#Glyphosate_resistance>
(December 15, 2006)
“Roundup” <http://en.wikipedia.org/wiki/Roundup>
(December 7, 2006)
“Euglena gracilis”
<http://bio.rutgers.edu/euglena/Euglenas/Egracili.htm>
“Glyphosate” <http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlorglyphosate/glyphosate-ext.html>
“Effects of Glyphosate on Euglena gracilis” <http://www.pmraarla.gc.ca/english/pdf/prdd/prdd_d9101-e.pdf>
(November 22, 1991)