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Researched by Casey G.
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The purpose of this experiment was to determine if plants grow better
with light, dark or light and dark.
I became interested in this idea when I was flipping through my science book and I found a lot on plants.
HYPOTHESIS
My hypothesis is that the plant with the mixture of light and dark will grow better.
I base my hypothesis on what I already know about outdoor plant growth, some experiments I read in my science project book, and the reading I’ve done on photosynthesis.
EXPERIMENT DESIGN
The constants in this study were:
-The same room temperature
-The same amount of water
-The same amount of seeds
-The same amount of sponges
The manipulated variable was amount of light.
The responding variable was the height of the plants.
To measure the responding variable, I used a ruler (in centimeters).
| QUANTITY | ITEM DESCRIPTION |
| 3 | Sponges |
| 3 | shallow containers |
| 20*3 | seeds |
| 1 | 100 watt light |
| 1 | ruler |
PROCEDURES
1. Gather all of the materials.
2. Pour 2 cm. of water into one of the shallow containers.
3. Place a small sponge on to the water.
4. Place 20 seeds on the sponge.
5.Spread the seeds apart so they don’t touch each other.
6.Put a light over the container.
7. Complete tasks 2-4 two more times.
8. Put pans #1 and 2 under the light leaving pan 1 under the light
full time and pan 2 under the light during daytime only.
9. Put the third pan in total darkness.
10. Add water daily to bring water level to two centimeters.
11. Turn on light for pan # 2 around 7:00 AM.
12. Turn off light for pan # 2 around 7:00 PM.
13. Measure heights of plants daily.
RESULTS
The original purpose of this experiment was to determine if plants grew
better with all light, no light, or a mixture of some light and some dark.
The results of the experiment were that the plants with a mixture of light and dark grew the tallest.
CONCLUSION
My hypothesis was that plants would grow better with a mixture of light
and dark.
The results indicate that this hypothesis should be accepted.
Because of the results of this experiment, I wonder if I should have
put the light further up.
If I were to conduct this project again I would try to get a larger
sample size, try to redo the experiment to se if I would get the same results,
try to get more seeds in a group, and try to get different species.
| REASEARCH REAPORT
Plants make their own food, their leaves are natures food factories. Plants take water from the ground through their roots. They take a gas called carbon dioxide from the air. Plants use sunlight to turn water and carbon dioxide into glucose (sugar). This process is called photosynthesis. Plants use glucose as food for energy. A chemical called chlorophyll helps make photosynthesis happen. That is what gives plants their green color. Winter days are short. Many plants stop making food in the fall, which makes the chlorophyll goes away. Then we can see orange and yellow colors. These colors were in the leaves all summer, but the green colored them up. Some leaves turn red. This color is made in the fall, from food trapped in the leaves. Brown colors are also made in the fall. They come from wastes left in the leaves. During long summer days there are longer hours of light and plenty of water, plants are busy making and storing food and growing. In winter there is shorter daylight and less water. Plants have different ways of getting through the cold winter. As plants grow the shed their old leaves and grow knew ones. This is good as old leaves get damaged because of (insects, disease and weather. Deciduous trees (maple, oak, and elm) shed in fall to prepare for winter, but evergreens keep most of their leaves during winter. Evergreens continue photosynthesis during winter if they get enough water. Many changes happen to leaves of deciduous trees before they fall. The leaves start getting ready for autumn in the spring. In fall the small tubes in the leaf that carry water swell shout cutting off flow. Without any fresh water able to reach the leaf the chlorophyll begins to disappear. Other colors that have always been there now become visible. With time the water between the tree and the leaf gets cut off and a wall is formed that will become brittle and will eventually fall and the leaf will blow away. |
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BIBLIOGRAPHY "Photosynthesis," World Book Encyclopedia 2000 "Photosynthesis," Encarta Encyclopedia 2000 Whitmarsh, John. "Photosynthesis." [Internet] Available Http://www.life.uiuc.edu/govindjee/paper/gov.html "Photosynthesis." [Internet] Available http://ericir.syr.edu/Projects/Newton/9/phytosy.html "Photosynthesis." [Internet] Available http://phtoscience.la.asu.edu/photosyn/study.html |
ACKNOWLEDGEMENTS
I would like to thank the following people for their help with my project
- My mom helped me find a lot of things on the Internet that had something to do with plants or photosynthesis.
- Mr. Newkirk helped me a lot by pushing us until the end, and let us stay after school until 6:00 to work on our science projects in his classroom.
- Mrs. Pasckale helped me with pasting and cutting.
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