1. Sherrie Adduci
Geoscience P.7
October 1, 2010
Understanding Systems Lab
Introduction:
The forest consists of trees, soil, watcher and air, plants and animals. These are
the elements of a forest, but the parts alone do not form a system. A living system,
which has both living and nonliving parts, is called in ecosystem. Some systems change
so slowly they seem as though they do not change at all. Forests may seem that way to
people who merely use them for camping, hunting or fishing. In this lab, systems are
observed and recorded over time to depict their alterations in an atmosphere filled with
natural and artificial lighting, as well as a systemwith no light at all. As evidenced by
figure 1, two lab tubes hold water, two hold an aquatic plant, two hold one tadpole, and
two hold both aquatic plant and a tadpole. One group of these tubes resided in the light,
while the other stayed in the dark. Elodea is an aquatic plant of a species that include
ornate waterweeds. Tadpoles are aquatic larva of an amphibian, including frogs, toads,
newt and/or salamanders. They breathe through their gills, and lack legs until the later
stages of their development. Through this lab it is discovered how light, or the lack of
light, can affect the organisms in an aquatic ecosystem.
Research Question: How does the lack of light affect an aquatic ecosystem?
Hypothesis: System in the light will survive more, the plant will be fine, tadpoles alone
will die, and both together will be content. System in the dark will suffer, all systems will
die out at similar times.
Materials:
 Bromothymal Blue
 Tadpoles
 Leaves
 Tubes
 H2O

2. Procedure:
The first step one must do in order to create their very own ecosystem is to
confine a considerable quantity of tadpoles, water, and plant material from a nearby
pond. In an average sized tank, one must hold the tadpoles with pond water and the
plant material. One must use eight test tubes and there are two different sections
utilized. One section dedicated to remaining in the dark, while the other would reside in
the light. Two test tubes need to be filled with water, this is the controlled variable. Two
test tubes must be filled with both water and a tadpole, and two test tubes must be
filled with water, a tadpole and plant material and two test tubes must be filled with
water and plant material alone. Four test tubes, one with a tadpole, one with water, one
with a tadpole and plants and one with plant, required stoppers placed on top of the
test tubes prior to their placement in the dark atmosphere.
Data Observation:
DATE IN THE DARK IN THE LIGHT
August 23, 2010  Tadpole aloneis still
alive.
 Water (control) – bluish
on top, oxygenated
 Plant– not
photosynthesizing,
givingoff carbon
dioxide.
 Tadpole and plant- the
tadpole is dead and the
water is yellow.
 Tadpole is alive
 Plantand tadpole =
alive,water has a blue
coloring.
 Plantand water: thicker
(photosynthesizing,
growing) the water is
blue, and the plantis
growing new leaves.
 Controlled water is
bluish.
August 25, 2010  Control has a blue tone.
 Water and tadpole,
tadpole is alive.
 Just plant= less plant
material
 Tadpole and plant-
tadpole is dead,plantis
almostdead, floating
white substances,
fungus too.
 Just tadpole – dead,
yellowish water
 Tadpole and plant –
water color is blue,the
tadpole is alive.
 Just plant– alive,
healthy, bluish water.
August 29, 2010  Just tadpole – alive,no
food
 Tadpole with plant –
dead tadpole, plantis
dead.
 Only plant– yellow,
 Just the tadpole –
decomposing, yellowish
water
 Tadpole with plant–
blue water, plantis just

3. plantmaterial looks
unhealthy a bit of
decomposition.
as big.
 Just plant– area of plant
is not changingmuch
August 31, 2010  Just tadpole – alive,
yellowish
 Plantand tadpole – still
dead, mold fungus. Less
plantmaterial,yellowish
white growth
 Just plant– mostly dead
 Controlled – stuff
growing, bacteria,still
blue water
 Just tadpole –
dissolving,broken up
into pieces,no longer
visible
 Tadpole and plant –
alive,bluewater
 Plantonly – bluewater,
plantis alive
September 6, 2010  Just plant– yellow,
greenish, quantity of the
plantitless
 Tadpole and plant –
tadpole is dead,plantis
decaying
 Just tadpole – still alive
and active
 Just tadpole – dead
dissolved
 Tadpole and plant- plant
material is healthy,
tadpole is alive,water is
blue
 Just plant– water is
blue, greater amount of
plantmaterial
September 14, 2010  Just tadpole – no
movement, yellow
water
 Plant– on to the
decomposing mode,
dying, yellowish
 Plantand tadpole –
tadpole is dead,in four
different pieces
 Tadpole and plant –
both arealive,water is
blue
 Just plant– alive,green,
blue water (bluer than
controlled group)
 Just tadpole – tadpole is
disintegrated,the water
is murky
September 27, 2010  Tadpole is dead and the
plantis still somewhat
alive,itis dying.
 Just plant– dead, yellow
 Just tadpole –
disintegratein pieces
 Just tadpole – all
disintegrated but brown
material areat the
bottom of the test-tube
 Tadpole and plant –
dead tadpole, plantis
alive
 Just plant– alive,
increased size,blue
water.

4. Figure 1
Conclusion:
In some ways the hypothesis is correct, the systemin the light did survive better
than the systemin the dark. As predicted, the plant in a test tube alone flourished and
remained alive, while the tadpole in a test tube alone disintegrated at the bottom of the
test tube and died. But, the hypothesis was wrong in predicting that the test tube that
held both the plant and the tadpole, the plant lived and the tadpole did not. There are
no specific alterations I would make if this lab were done again, because the lab is about
a system and what is necessary to keep a systemalive. We are testing this, so we don’t
want every system to be alive and perfect in the end, because the flaws help us to
discover the answer to the research question. The lack of light effects an ecosystem
drastically because compared to the system in the light, the system in the dark killed the
tadpole and plant in the same test tube, killed the plant that was alone and destroyed
and killed the tadpole that was alone.