The effects of water contaminated with shampoo, detergent, or Tylenol on the rate of photosynthesis Hannah Brenner, Austin Saxton, Kevin Rosenbrook, Emily Mecum

Background Information  The independent variables are common households items that usually go down the drain, which can contaminate the water run off and affect plant life.  There has been one study on the effect of Tylenol on algae growth in which the Tylenol negatively affected the florescence of the algae.

Independent Variables All three of the variables, laundry detergent (Tide), shampoo (Suave), Tylenol have been shown to have negative affects on plant life.

Purpose The purpose of our experiment is because many household items are put down the drain and can move into the soil. We want to see whether or not some of the more common things washed down the drain actually hurt the rate of photosynthesis.

Hypothesis  We believe that all three experimental groups will have a lower rate of photosynthesis compared to the control, Thus making their floating time in the sodium bicarbonate solution longer. The painkiller and the shampoo plant will not float at all, and the detergent plant will take between half an hour and an hour to float while the control will take less time. (In short, all contaminants will have a negative affect on the rate of photosynthesis.) (In short, all contaminants will have a negative affect on the rate of photosynthesis.)

Procedure For our experiment we grew our bean plants from seeds. We kept everything constant including soil, type of plant, amount of water and sunlight they each received. We applied our variable by giving the plant water mixed with one of our 3 contaminates. We applied the contaminated water twice to each plant. After this we conducted the floating disk test.

Our plants before we tested them…

Data

Number of Floating Discs Present TIMECONTROLTYLENOLSHAMPOODETERGENT Our time table telling us when each of the disk began floating

P-Values TylenolShampooDetergent P(T<=t) E E-07 Reject/ Accept Reject Null Hypothesis: The contaminants will not have an effect on the rate of photosynthesis Each P-Value was taken by running a t-test between a variable and the control.

Limitations  Amount of time  3 of our plants didn’t grow so we couldn’t have two trials  Sample size was too small  Plants weren't fully mature and different sizes  Didn’t receive the exact amount of contaminates  Growing conditions weren't the best  Our control didn’t float

Conclusion The Tylenol, Shampoo, and Detergent contaminants were hypothesized to have a negative influence on the rate of photosynthesis. Yet the three contaminated bean plants were found to have a faster rate of photosynthesis than the controlled bean plant, as seen in the results. This implies that the contaminants were a positive influence, thus discrediting the hypothesis. However, without the essential replication of trials, it is very difficult to confidently accept these results. Secondly, had the control performed normally (if not better), it is likely that the results would have been much different.

Credits   Dr. Golonka   Mrs. Coury   Our Beautiful Bean Plants