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?

If visible light provides a spectrum of red through violet, then red, blue, and violet light will make the plant grow the fastest and green and yellow light will make the plant grow the slowest.

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 adding different plant seeds and then measuring the different heights the plants grew over 30 days with different color light.  The controlled variables were the duration, same unit of measure (cm), same amount of light, and same amount of seeds.

Results:

Filter Color	Spinach Avg. Height (cm)	Radish Avg. Height (cm)	Lettuce Avg. Height (cm)
Red	17.3 cm	12.67 cm	11 cm
Orange	15 cm	8.67 cm	7.3 cm
Green	2.3 cm	2 cm	3.67 cm
Blue	19.3 cm	15 cm	12.67 cm
Violet	16 cm	10.3 cm	9.3 cm

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.

The data I gathered during the duration of this experiment supported my hypothesis that red, blue, and violet light would make the plants grow faster.  For each category of plant seeds, the red, blue, and violet grew much larger than the other light colors.  The red plant heights were 17.3 cm, 12.67 cm, and 11 cm for spinach, radish, and lettuce, respectively.  The blue plant heights were 19.3, 15 cm, and 12.67 cm for spinach radish, and lettuce, respectively.  The violet light heights were 16 cm, 10.3 cm, and 9.3 cm for spinach, radish, and lettuce, respectively.  The green light plants did not even reach 5 cm for any of the plant seeds.  Among all the seeds, I noticed that all the red,  blue, and violet light plants grew the highest and the green light plants grew the least.

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

I can conclude from this experiment that the plants light spectrum absorb the most light from the ends of the spectrum.  The wavelengths should either be really short or really long.

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

Under white light, I would expect the averages of all the colors because the plants will absorb all the different colors in a different way, so the white light would reflect the average.

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:  Will light intensity affect the amount of oxygen bubbles that will be released?

Hypothesis:  If more light will produce more oxygen, then the amount of oxygen bubbles will increase with higher light intensity.

Experimental parameters:

30 seconds

25 degrees

Blue light

Least amt of carbon dioxide

• Dependent variables: Amount of oxygen bubbles produced 
• Independent variables:  Light intensity (0%, 10%, 25%, 50%)
• Constants:  Same time (seconds), temperature (degrees Celcius), and carbon dioxide (empty bottle)
• Control:  0% light intensity

Experiment Data Table (Measured in amount of bubbles)

	0% light intensity	10% light intensity	25% light intensity	50% light intensity
Trial 1	0 bubbles	9 bubbles	13 bubbles	15 bubbles
Trial 2	0 bubbles	9 bubbles	13 bubbles	14 bubbles
Trial 3	0 bubbles	10 bubbles	13 bubbles	14 bubbles

In this lab, we asked the question, “Will light intensity affect the amount of oxygen bubbles that will be released?”  I found that the more intense the light is, the more the plants will produce oxygen bubbles.  After three trials for each light intensity, I found an average of 0 bubbles for 0% light intensity, an average of 9 bubbles for 10% light intensity, and an average of 14 bubbles for 50% light intensity.  This quantitative evidence shows that if the plants that are exposed to more intense light, then the plants will produce more oxygen to areas where there is less light.

This lab was done to demonstrate how the intensity of light would affect the amount of oxygen produced.  From this lab, I learned that the plants need to be exposed to more intense light in order to produce more oxygen.  The conclusion to this lab makes sense because in class we learned that the more of something but in, the more will come out.  Using the equation I learned in class, 6CO2 + 6H20 = C6H12O6 + 6O2, I can conclude that if we added more of one thing on the left side, the more will come out from the equation because the more of one variable you put in, the more of another thing will pop back out.  This lab helped me understand the concept of photosynthesis because I was able to manipulate one part of the photosynthesis equation and see how if affects the amount of product it will produce.  Based on this experience from this lab, if I wanted to grow my own plants in a garden, for example, I would know how to make the plants grow faster.  If I have any problems growing my plants, I could think about what I did in this lab to see how to make the plants grow at the normal rate or even faster than the normal rate.