| Explore | -Soil can affect the germination of a plant. -Plants can stop each other from growing -The first part of the plant that emerges from the seed is the radicle -Not all plants act the same when dealing with competition -Some plants need to be exposed to extreme cold/heat in order to germinate -Allelopathy is the inhibition of growth in one species of plant caused by chemicals that are released by other plants -Some seeds prefer different temperatures to start germination and continue to grow. |
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| Research Question | How will plants grow differently with different levels of exposure to light? Why do these plants do this? How could it benefit the plant |
| Predictions | The seeds in dark conditions will grow faster because seeds usually only need contact with soil, water, and the right temperature for germination. |
| Experimental Design | Constants - The same type of petri dish, same amount of water, same location, same temperature, the same seed Independent variable - The amount of light/darkness Dependent variables - Temperature of soil, less growth, humidity, water/CO2 used We will take detailed notes, sketches, photos, and measurements to make sure we get good data. Procedure: Start: Observe unsoaked seeds, take a photo. Soak seeds in water overnight Take observations of the soaked seeds, take a photo. Get all Petri dishes ready/ prep light bulb, dark box, and where we are putting the control. Close off dark enclosure with Petri dish in it/ plug-in the light bulb, and place Petri directly under it. Place other Petri dish another petri dish on a windowsill. Set up third petri dish with a bowl over it to block out all light. Place damp paper towels in Petri dishes, put designated seeds on top of the paper towel. Come back the next day, record observations, take a photo, spray seeds with water once, return seeds to their controlled environment. Rinse and repeat “number 7” until the end of the experiment. Repeat all previous steps 2 more times to get more data. Daily data recording: Take photos of all three Petri dishes Measure radicles Make observations Sketch seeds Return to areas Watering: Take all of the Petri dishes from their enclosure things Spray lightly with water once a day. Return individual Petri dishes to their own areas. Materials: - Petri dishes - Water - Soybeans - Paper towel circles - Container (to keep light away from the seed supposed to be in darkness) - A small light |
| Conclusion | Through this experiment, we have seen that soybeans grow more in darker, possibly cooler places, but can still manage to grow in better lit places. Throughout the experiment, our seeds had a light tan color, with one black spot on the side. With the seeds in lower levels of light, the radicle length, and germination and growth speed are much higher, but since we weren’t able to run the experiment for longer, we were not able to see whether these things would end up helping or hurting the overall growth of the plant once it can photosynthesize. |
| Investigation Theme | WOS |
| Grade Level | Middle School Students (grades 6,7,8) |
| School Name | San Francisco Friends School |
| Session | Spring 2019 |