Photosynthesis Lab
Hypothesis: A change in the intensity and the wavelength of light on plants would result in a decrease in photosynthesis in plants as long as the change of the wavelength is not the same color as the plant. So for example having red light on a red plant.
Materials:
Materials:
- scissors
- black construction paper
- potted plant
- tape
- blue,red,and green cellophane
- 5 large test tubes
- glass- marking pencil
- forceps
- 400 mL beaker
- 5 petri dishes
- iodine solution
- paper towels
Experiment
Day 1- covered leaves with black paper and colored cellophane. Covered about 4 leaves with black paper and red cellophane on red colored leaf plant and green colored leaf plant
Day 2 -Removed the leaves, removed chlorophyll by putting leaves in a test tube and placing them in boiling hot Ethonol. Then we rinsed the leaves off and placed them in separate petri dishes according to leaf color and covering that was on them. Then we took iodine and placed them on each leaf and observed the color change.
Day 2 -Removed the leaves, removed chlorophyll by putting leaves in a test tube and placing them in boiling hot Ethonol. Then we rinsed the leaves off and placed them in separate petri dishes according to leaf color and covering that was on them. Then we took iodine and placed them on each leaf and observed the color change.
Results
The leaves that did not have any changes to them retained their green color with the iodine. The leaves with the change in wavelength showed some positive results for iodine testing. The leaves that had the black paper over them showed very minimal amounts of starch with the iodine test.
Conclusion: + Analysis: So in the lab we looked at the effects of wavelength and intensity on photosynthesis. The black paper showed a decrease in intensity and the red cellophane showed a change in wavelength from regular sunlight. The black paper shows a decrease in intensity of sunlight on the leaf. The lower intensity of light decreases the light dependent processes in photosynthesis and less starch would be made, making a negative test for starch with iodine. The red cellophane on the green leaf would decrease the amount of light going onto the leaf decreasing photosynthesis. The cellophane on the red leaf would not effect anything because they are both reflecting the same light and accepting the same light.
Reflection
This lab was a little more complicated to try and figure out with just materials. We eventually did figure it out, putting on the paper on the leaves. The next day was more fun dealing with the boiled leaves and the iodine to figure out the starch. The group I worked with did well together and we stayed on task most of the time.