Photosynthesis Virtual Labs

Photosynthesis Virtual Labs.

Lab 1: Glencoe Photosynthesis Lab

http://www.glencoe.com/sites/common_assets/science/virtual_labs/LS12/LS12.html

Analysis Questions

1. Make a hypothesis about which color in the visible spectrum causes the most plant growth and which color in the visible spectrum causes the least plant growth?

Since in the vodcasts, it said that plants grow best under red or blue light, my hypothesis is that if a plant is that if a plant is put under red or blue light, then it will have the most plant growth.

Also, plants reflect green light, so my hypothesis is that when put under green light, plants will have the least growth.

2. How did you test your hypothesis? Which variables did you control in your experiment and which variable did you change in order to compare your growth results?

I tested my hypothesis by putting the same plant under different wavelengths (colors) of light. For my control, I used white light, as it contains all the different colors and acts as a good base measurement of how much the plant should grow. The variable I changed was the color on the left side, so I could compare it to normal while light and see what would happen.

Results:

Filter Color	Spinach Avg. Height (cm)	Radish Avg. Height (cm)	Lettuce Avg. Height (cm)
Red	18	13	11
Orange	14	8	6
Green	2	1	3
Blue	19	14	12
Violet	16	10	8

3. Analyze the results of your experiment. Did your data support your hypothesis? Explain. If you conducted tests with more than one type of seed, explain any differences or similarities you found among types of seeds.

My data definitely supported my hypothesis. All the seeds that grew under the same color of light ended up having pretty consistent heights. The plants that grew under the blue lights and red lights were always significantly and consistently taller than those that grew under violet or green light.

4. What conclusions can you draw about which color in the visible spectrum causes the most plant growth?

The color in the visible spectrum that causes the most plant growth is without a doubt blue. The height of the plants that grew under blue light always exceeded the height of those that grew under other colors.

5. Given that white light contains all colors of the spectrum, what growth results would you expect under white light?

I think that when the plants are placed under white light, which contains all the colors of the spectrum, the growth of the plants would be similar to that of the plants that grew under violet light--not quite as tall as plants under blue or red light, but taller than those that grew under orange or green light.

Site 2: Photolab

http://www.kscience.co.uk/animations/photolab.swf

This simulation allows you to manipulate many variables. You already observed how light colors will affect the growth of a plant, in this simulation you can directly measure the rate of photosynthesis by counting the number of bubbles of oxygen that are released.

There are 3 other potential variables you could test with this simulation: amount of carbon dioxide, light intensity, and temperature.

Choose one variable and design and experiment that would test how this factor affects the rate of photosynthesis. Remember, that when designing an experiment, you need to keep all variables constant except the one you are testing. Collect data and write a lab report of your findings that includes:

• Question
• Hypothesis
• Experimental parameters (in other words, what is the dependent variable, independent variable, constants, and control?)
• Data table
• Conclusion (Just 1st and 3rd paragraphs since there's no way to make errors in a virtual lab)

*Type your question, hypothesis, etc. below.  When done, submit this document via Canvas.  You may also copy and paste it into your blog.

Question: How does the amount of carbon dioxide in system contribute to the amount of oxygen produced by photosynthesis?

Hypothesis: If carbon dioxide is required for a photosynthesis reaction to happen, then more carbon dioxide will cause more photosynthesis and therefore produce more oxygen.

Experimental Parameters: The independent variable is the amount of carbon dioxide and the dependent variable is the amount of oxygen produced. Some constants include the amount of light, color of light, the amount of water, the type of plant, the amount of time, and the temperature. The control was no carbon dioxide.   

Amount of Carbon Dioxide	Trial 1 (bubbles in 20 sec)	Trial 2	Trial 3	Average
None added	16	16	16	16
Some added	28	28	28	28

Conclusion: In this lab, I asked the question: How does the amount of carbon dioxide in system contribute to the amount of oxygen produced by photosynthesis? I found that it greatly increases the amount of oxygen bubbles created, almost doubling the amount without carbon dioxide. When I didn’t add any extra carbon dioxide to the system, only 16 oxygen bubbles were produced in 30 seconds while in the system with extra carbon dioxide, there were 28 oxygen bubbles. This is likely because of the fact that carbon dioxide is required to start a photosynthetic reaction. Adding more carbon dioxide gives the plant more reactant to work with, which is most likely the cause of why there is way more product.

This lab was done to demonstrate how different environmental factors affect the process of photosynthesis. From this lab, I learned that more carbon dioxide produced more oxygen, which helps me better understand the concept of the chemical reaction behind photosynthesis. Based on my experience from this lab, if I am a botanist in the future, I might leave my plants in an area with higher concentrations of carbon dioxide to help them grow better.