Snail and Elodea
Investigation
Directions:
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Plan an investigation to collect data to
support or contradict 7 hypotheses
proposed in this investigation.
Questions:
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How are plants and animals
interdependent on one another?
How is carbon cycled between plants
and animals?
Hypotheses:
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1:
2:
3:
4:
5:
6:
7:
Snails give off CO2 in the light.
Elodea takes in CO2 in the light.
Elodea uses CO2 snails give off in the light.
Snails give off CO2 in the dark.
Elodea takes in CO2 in the dark.
Elodea uses CO2 that snails give off in the dark.
Elodea gives off CO2 in the dark.
Materials
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glass vials with lids
test tube rack
distilled H2O
pond snails: Lymnaea
water plants: Elodea
bromthymol blue (BB)
straw (to add CO2)
wax pencil
lamp with 60 watt bulb
dark cabinet
Procedure:
Brainstorm Hypotheses 1-3
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H1: Snails give off CO2
Experimental vs. Control set-up
H2: Elodea takes in CO2
Experimental vs. Control set-up
H3: Elodea uses CO2 snails give off
Experimental vs. Control set-up
Hypotheses 4 -7
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How will you set these up?
Infer an appropriate design to test
hypotheses 4-7
Create a table to represent the
experimental and control procedure
Make specific predictions for
experimental and control treatments