||What we know about plants outside from school is that they need light and water to grow.What we have discovered is that plats actually use that light and water to go through photosynthesis. Our questions are, do all plants need the same kind of water to grow? Why do some plants take longer to grow than others?
||We want to study if the type of water affect plants rate of photosynthesis. We got the ideas from one of the ideas that Mrs. Rogers was showing. The question fits with the topic because we want to know if plants can survive in different water conditions.
||What we think will happen is that more leaf disks will float in the salt water than in tap . We think this will happen because salt water contain more carbon dioxide in it than tap water.
||1.The independent variable is the rate of photosynthesis.
2.The dependent variable is the type of water the plants will be in.
3.The control variable will be the amount of water each cup gets, the same cup, the same number as leaf disks, the temperature, the same amount of light, and the same amount of time they will be under the light
4.We will gather the data by observing each cup with the leaf disks every 3 minutes and see how many disks are floating.
- One regular heat lamp
- 2 container cups
- 2 spinach leafs ( 20 leaf disks)
- Whole puncher
- 2 syringes
- 150 mm of salt water
- 150 mm of tap water
-Label one cup tap water and the other salt water using the tape
- Fill one cup with 150 mm of salt water and the other with 150 mm of tap water
- Whole punch 20 leaf disks from the spinach leafs
- Remove the bottom part of 2 syringes and place 10 leaf disks in each syringe
- Place back the bottom part of the syringe
-With the first syringe suck in about 1/3 of tap water from the cup
- With the second syringe suck in about 1/3 of salt water from the other cup
- Take out all the oxygen from inside the syringe by cover the tip with your finger and pulling back on the syringe until leaf disks to sink (do this to both syringes)
- Once all leaf disks have sunk take the bottom part off of each of the syringes and release the leaf disks in their proper cup of water.
- Place the cups with the leaf disks under the lamp
- Record the number of leaf disks floating every 3 minutes and writ it down
||We can claim that salt water increases the rate of photosynthesis for spinach leafs disks. It is possible that more disks float in the salt water because it contains more carbon dioxide than tap water. The data we collected proves our claim because after 15 minutes under the light ( leaf disks were floating in the salt water and only one was floating in the tap water. other experiments that can be done to expand this is comparing salt water to other types of water besides tap water.
||High School Students (Grades 9,10,11,12)
||Paramount High School West Campus