Lab # 2: How does your biome grow?
Problem: What impact do abiotic factors have on biomes?
Hypothesis: If I add different leaves and twigs and other abiotic factors such as these into
the bottle along with my seed and soil, I think it will reduce the growth rate and health of
the seed or prevent it from growing altogether.
Materials:
 2-liter bottle
 objects found in nature (twigs, grass, etc.)
 potting soil
 seedk
Procedures:
 Search outside for objects produced and found in nature
 Collect these objects
 Pour potting soil into the 2-liter bottle
 Insert the seed in the soil
 Place the objects collected in nature into the bottle
 Observe the growth of the seed over a period of time
 Record your observations
Data & Observations:
After leaving our bottle to sit with its contents for about twenty days, a few changes
occurred. For one thing, our grasshoppers living in the bottle did not live. After about
three or so days, they died. In addition, am odd, cotton-like substance began to form on
the grasshopper and around it. This substance could either be mold or a cocoon of some
sort. All of the grass died in the bottle and became a yellowish color. However, the seed
we planted did not grow at all as far as one can tell. The leaves on twigs we inserted into
the bottle turned into a blackish color and died. Essentially, this mini-biome was unable
to sustain any sort of life
Analyze & Conclude:
1. On which abiotic factor did you focus? Why?
The abiotic factors on which we focused were whatever matter we put into the bottle.
This included grass, twigs, soil, and flowers. We put these in to see if they would affect
the growth of the seed
2. Did this abiotic factor seem to have a significant impact on the dependent variable
in your simulated ecosystem? Explain.
These abiotic factors may have had some affect to the growth of the seed (dependent
variable) because they blocked sun light and little water was able to reach the soil of the
seed.
3. Describe the control in your experiment. What was held constant in the control?
Why was it set up that way?
The constant in this experiment was how much air would be able to flow through the
bottle. We left the cap off, so plenty of air made its way into the bottle. Also, we
controlled the fact that no water was allowed into the bottle.
4. How does your experiment relate to biomes and abiotic factors in nature?
Our experiment is parallel to the situation and the results of a biome that has too much
organic matter and no water. Things can’t grow if they can’t obtain sun light or water,
which is what happened to the seed and soil in our experiment.
5. What are some possible sources of error in your experiment?
Some possible sources of error in our experiment are that there may not have been
enough soil, other people may have messed with the bottle, or the decomposition of the
organic matter may have caused problems with the growing progress of the seed.
6. Exchange your procedure and data with another group in your class. What do
their data show about the biome they chose to simulate? What conclusions can
you draw about the abiotic factors in a biome?
Another group that inserted similar or the same organic matter turned out the same way
that ours did. Their experiment also showed that nothing can grow in the type of biome
that we exemplified with our bottles. This shows that the abiotic factors in these biomes
prevent anything from growing.
7. What are the limitations of the design of this experiment? Are there additional
factors at work?
This experiment confines all observations to a very small area that doesn’t allow us to
include multiple organisms or factors, which could change the outcomes completely.
There might be other factors at work that we can’t observe such as the tint of the bottle
preventing additional sunlight from reaching the soil.
Write and Discuss
Write a short paragraph describing your findings and indicating whether or not they
support your hypothesis. Discuss any questions your reults have raised.
In conclusion, my hypothesis was overall incorrect. The seed that we planted did not
grow at all, despite that I guessed they might grow a little. Additionally, any plants, such
as twigs, grass, or flowers that we put into the bottle also died over a short period of time.
We also had two grasshoppers in the bottle, but within a couple days, both of the
grasshoppers also died. An odd, cotton-like substance grew on the grasshopper. But aside
from the odd fuzz, no life was sustained in the bottle.
1. Describe the rainfall pattern and abiotic factors that make up the biome you live
in. How do these factors impact the plants, animals, and agriculture in your area?
There is not a very constant rain pattern in the biome where I live, so this causes a lack of
green autotrophs to be able to survive in this biome. Also, some of the abiotic factors
such as water and the soil directly tie in with the lack of rain. Since we get little water,
the oil is not rich enough to grow a vast amount of plants. Also, the strong wind causes a
dilemma from some plants and animals to survive. With the weather changing drastically
between summer and winter, it forces many animals and plants to appear seasonally.
2. If you were to maintain your biomes in the classroom or at home, what abiotic
factors would you change from your original model? Make a prediction about
what you would observe under the new conditions.
If I were to maintain the biome created in class, I would add water to the soil in the bottle
constantly to help aid the seed in growing. Also, I would make sure that the bottle would
be exposed to more light than it was in the classroom.