ReviewWarmup. What is a variable?What is made during photosynthesis?Where is there more oxygen, a lot of photosynthesis or a little.

A variable is any factor of an experiment that can be changed.

What Kind of plantWaterBagsLightAmount of Co2

Variable

Three types of variablesControl- What stays the sameManipulated_What you change before the

experiment. Responding_The variable that is observed or

measured.

What batter is the best? Put them in flashlightsTurn on the flashlightsRecord how long each Flashlight stays on.

Battery experiment

Battery ExperimentManipulated Variable

BatteriesResponding Variable (dependent variable)

Length light stays on. Control variable

Same flashlightSame time startedSame temperature

Experiment 2What kind of coffee cup keeps coffee

warmest. Look for

Manipulated variableControl variablesResponding variable

experiment

Manipulated VariablesWhat was the manipulated variable?

These are the variables you set up. What is different in the experiment

Responding variablesWhat was the responding variable. The responding variable is what you observe.

We observed the change inTemperature

Control variableWhat parts of the experiment were kept the

same. Always use the same measuring devices. Same thermometerSame amount of waterSame beginning temperature.

Amount of variablesHow many manipulated variables can we have?

How come we can only have one?What happens if we had different batteries AND different

flashlights, AND different temperatures they were tested in?

Do we know which battery is truly better? Could have better flashlight Temperatures can make batteries last longer.

YOU CAN ONLY HAVE ONE MANIPULATED VARIABLE AT A TIME. This is so you know what exactly is causing the

dependent variable.

Elodea experiment.

You will do three experiments.

For each experiment give:    Hypothesis: What do you expect will give you the most

photosynthesis?    Manipulated Variable: Which Variable are you testing    Control Variable: What variables are you keeping the same?    Responding Variable: Bubbles Data table, 

Do 4 tests with 4 different variables and record your data. 

ConclusionHow does this variable affect photosynthesis?, 

Elodea experiment.

Predictions? HypothesisWhat color will work best?

PlainRed Green Blue, What will happen when we increase CO2What will happen when we increase the light

level?

Our LabYou will record Data Table. Change only one variable at a time.

You then know this effect on the photosynthesis.

You will do 4 runs for each variable. Test the effect of Light LevelTest the effect of light colorTest the effect of carbon dioxide

ResultsChart your data. List the level of all the variables and the

result