Experimental Design |
Variables
Independent : Color of light
Dependent : Number of leaves floating (Rate of photosynthesis)
Control: Temperature, intensity of light, time under light, type of leaf, amount of water
Question
What is the effect of color light on the rate of photosynthesis?
Hypothesis
The blue light will have the greatest rate of photosynthesis.
Materials:
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Pre lab 1.
2. 3. 4. 5.
4 colored lights (blue, green, red, white) 4 styrofoam cups of water
sharpie
4 spinach leaves
hole punch
1⁄4 tsp baking soda
graduated cylinder
4 syringes
paint brush
Dishsoap
protocol:
Label 4 styrofoam cups A, B, C, D.
In a beaker, measure 600mL of water.
Measure in 1⁄4 tsp of baking soda and mix with paintbrush. Measure in five drops of soap and mix
With the hole puncher, punch 50 holes out of the spinach leaves.
Protocol:
1. Using graduated cylinder, fill each the 4 cups with 100mL of water.
2. Put ten leaf pieces in each syringe, labeling syringe A, B, C, D.
3. Lay syringe on its side, and push plunger in as far as possible without crushing the
leaves.
4. Pull up 6 mL of water from corresponding cups, and push back down, until a small
bubble of water appears at end of syringe.
Elle, Anosha, Josie and Annalise
5. Place finger over end of syringe and pull back on plunger, creating a vacuum, and shake. Release plunger THEN finger.
6. Repeat until all leaves sink within the syringe
7. WITHOUT TURNING LIGHT ON, Put cup A under blue light, cup B under green light,
cup C under red light, and cup D under white light.
8. At same time put leaves from corresponding syringes to cup. Poke down floating leaves
with end of paintbrush.
9. Turn all lights on and record data on how many leaf pieces are floating for ten minutes, recording every 60 seconds. |