|From experience, we know that plants need water and sunlight to grow and survive. There are many different types of plants with each having their own characteristics that help them survive. While taking AP Bio and through background research, we have learned that plants go through a process to...
|We wanted to test if the pH of a solution would increase/decrease with the presence of either oxygen or cellular respiration. This experiment was a continuation of our first experiment where we tested to see if plants could go through the process of photosynthesis or cellular respiration in both...
|Independent Variable: Light/Dark of Environment Dependent Variable: Before/After pH of the Solution Control Groups: Same Species of Plant, Amount of Time It Was In The Environment, Amount of Plant Disc In Each Cup The possible outcomes of our study was the increase/decrease of pH. We...
|We decided to use the leaves of the plant Scindapsus Jada Pothos. A member of our group punched out 36 discs from the leaves and separated it into groups of 6. Another member made a pair 3 different solutions leaving us with 6 different cups. Our first set of solution was limewater. In a cup we...
|From our experiment, we can make a claim that there was more carbon dioxide produced in the dark than in the light. We know that carbon dioxide is a product of cellular respiration and its counteract opposite is oxygen. Oxygen is a product of photosynthesis and photosynthesis can not happen in...
|About this Project
Good communication between the mentor and the students, and good record of the data. Students showed interest in the experiment making questions. -- Gabriela Hernandes Villani, Liaison
This group really worked together to communicate with their scientist mentor at every step of...
Thank you for all your time and helpful information throughout our project. Your suggestions and questions really helped us look deeper into our tests and experiments to learn more about photosynthesis. From Suki, Angie, McKenna, and Lairah!
We think the change in pH was so small due to two factors. The first one is that the sample we used of our plant was very small. Because we only used a few small hole punched disks, the CO2 released could have been a very small amount, and that could be why it did not affect the pH dramatically. The second reason is that we only left the experiment to change for about a day, so maybe we did not give it enough time to fully complete the process.
Our predictions were accurate and supported by the evidence from our experiment. However, we predicted that there was going to be a more dramatic increase/decrease in pH but we were wrong. Our results were not tooo dramatic meaning there was not a lot of carbon dioxide produced overall.
We think that without the presence of light, the amount of carbon dioxide would increase causing the pH of the solutions in the dark to decrease. Without light, plants can only go through the process of cellular respiration. When the plant is in light it would go through photosynthesis (producing oxygen) as well as cellular respiration (producing carbon dioxide).
Independent Variable: the light/dark environment in which the solution is placed in
Dependent Variable: The pH of the solution after 24 hours
Control Factors: the plant specie, the amount of time it was in the light/dark, the amount of water that was in the solution
Day 3 Update: We took our the 3 solution in the dark and measured the pH. The pH was lower than it was 24 hours previous which helped us determine that there was more carbon dioxide in the solution than there was 24 hours ago.
It was surprising to learn that plants do not need soil to photosynthesize. Plants use soil to obtain the little nitrogen they have in their system.
Day 2 update: The plant we used was the scindapsus jade pothos. We measured the pH of the solutions in light and the pH increased which was what we expected. Through photosynthesis, oxygen was produced which lowered the amount of CO2 and raising the pH. The solution is the dark were knocked over so we are redoing it. For the two cups in the dark that was not knocked over we measured the pH and was not what we expected so we are redoing it. We will keep you updated.
We are now doing our own experiment. We know that CO2 will make the pH of a solution more acidic when present. We decided to use this information to test for CO2 in different solutions with indicators. We made 6 solutions. In two cups, we used lime water as our indicator. In two other cups, we used phenol red. And in the last two cups, we used universal indicator to test for the presence of CO2. We will be removing the oxygen from leaf disks that we punched out by using suction in a syringe. We will then add 6 disks into each solution we made. We will then put one of each solution we made into light, and one of each into dark. We will check back in 24 hours to see if any changes were made in the color from our indicator solutions. If so, we will determine if it was in fact CO2 that caused the change.
We wanted to confirm the role of Carbon, as well as rule out the specific functions of some parts of a plant growing gaining weight/ mass. After observation, and studying a different lab that tested the same thing, we saw that after 5 years, the soil where a tree seed was planted did not lose mass even though the tree was growing. From this, we could determine that the tree does not get mass from the soil. We then saw a chart with the common molecules in plants. We saw that carbon was the most abundant. So we looked where carbon was present, and saw that CO2 is a reactant input in photosynthesis. From this we determined that most of the trees mass would have come from carbon, and that the C is coming from CO2.
To answer your question: The carbiantion in the cup carbon dioxide, which is a reactant that is needed for photosynthesis.
We did a lab experiment with elodea and phenol red. There were 4 tubes that we filled with the phenol red solution, and then we put a piece of elodea in two of the tubes. Next we blew through a straw into all of the tube so that CO2 was present. The solution turned yellow when we did this, showing a pH drop. We took one tube containing elodea, and one without, and placed it in a dark space under a box. We did the same and placed the tubes by a bright light. After 24 hours, the elodea in the light turned the solution from yellow, to pink. This was because the CO2 was used up in photosynthesis. But, the solution of the elodea in the dark stayed yellow. This is because the CO2 was NOT all used up.
We may be doing the lab again so if we do, and get different results, I will update you with any changes!
We saw more bubbles in the baking soda cup than in the one without since the solution with baking soda was carbonated.
We believe, after studying the photosynthesis equation, that the gas is oxygen, because it is a product of the reaction. We will be continuing the lab on Thursday, and will update you with our results. During our lab we will use phenol red, an indicator for oxygen, in our solutions to help solidify our hypothesis.