Leaf Effect Lab Report

The purpose of this lab was to see which level of light (measured in lux) made Spinacia oleracea (Spinach) leaf disks float the fastest. Our hypothesis was that an increase in light intensity will decrease the time it takes Spinacia oleracea disks to float. If light intensity is increased, then the time it takes Spinacia oleracea disks to float will be decreased. The mean for the no light (0 Lux) sample and the low light (4 x100 Lux) sample was 1200 seconds with no standard deviation because none of the disks in these two samples floated. The mean and standard deviation for the medium light (110 x100 Lux) was 902 seconds +- 84 seconds. The mean of the high light sample (410 x 100 Lux) was 692 seconds with no standard deviation because only two Spinacia oleracea disks floated so there was no need to measure the variability of the data. The final results indicated that the highest light intensity led to the quickest rise of Spinacia oleracea disks, supporting our hypothesis.

This is because the plant was in the test tube by itself, and placed in the light so the elodea could freely photosynthesize, which would eliminate a large portion of the carbon dioxide within the tube.

The purpose of this lab is to observe the effect of white, green, and dark light on a photosynthetic plant using a volumeter and followed by the calculation of the net oxygen production using different wavelengths color of white and green light, and also the calculation of oxygen consumption under a dark environment, and finally the calculation of the gross oxygen production.

Wait, another 3 minutes. While waiting for Plant A to soak, proceed to put Plant B (the leaf exposed to no air through soda lime) into the same beaker of boiling water. Once time is up for Plant A, rinse the leaf with water and place leaf off to the side. Next, grab tongs and place Plant B directly into the beaker with alcohol solution (Making sure to grab new alcohol into the beaker and not using the same solution from Plant A). Wait, another 3- 5 minutes. Once time is up place Plant B, using tongs, into the petri dish and completely cover the leaf in iodine solution. Wait 3 minutes. Then rinse off the leaf and compare the coloration with Plant A. Record

14. At this point, a vacuum is to be created within the syringe to draw the air out of the tissue of the leaf disks. After this step, the experiment is really quite simple.

The hypothesis that red light would produce more dissolved oxygen was not supported by the results of the experiment. Without having more accurate data it is impossible to say which color light induced its plant to produce the most oxygen. The reason for not having more accurate data is because of the way of testing the dissolved oxygen. By testing with the dissolved oxygen tabs the data could not have been very specific and specific data is important for a good experiment. The way of getting much more accurate data is by testing with the Winkler's method. This way of testing for dissolved oxygen amounts would have not been possible to execute because of the amount of water and the size of tanks used. To test with the Winkler’s method it is necessary to test 200 mL at a time. If this way of testing for

Record the net rate of photosynthesis in the data and observations. Data/Observations: This data shows the amount of time it took for the spongy mesophyll in the leaf cells to collect carbon dioxide from the bicarbonate solution, causing photosynthesis and the leafs to float in the cup. Time (min) With CO2 (NaCO3) Without CO2 (H2O) 0 0 0 1

To test the rate of photosynthesis in spinach leaves, we placed a spinach thylakoids mixed with dichlorophenol-indophenol (DPIP) in front of various lights treatments. In total, there were 5 cuvettes which all received different lighting. One was a control which contained no thylakoids, another had no light at all, the third cuvette was completely open to all possible light, the fourth was covered with a green translucent paper, and the final cuvette was covered with a red translucent paper. In five minute intervals, the transmittance was measured using a spectrophotometer which allowed the rate of photosynthesis to be measured. Upon completion of this lab, the white light produced the highest rate of transmittance shortly followed by the red light and then the green light.

The forth factor which would affect the result of the experiment is objective. The leaf observed from the electroscope is not clear, during the experiment, only the outline of the leaf can be seen, which means the interval time for leaf from Mark 4 to Mark 3 is not correct because the leaf is not exactly right on the positions of these two marks. So the results could be improved by observing the leaf through leaf electroscope within the minimum error possible and for the skills for colleting data using specific apparatus also need to be improved and to be more familiar with the process of the

The plants will go through one complete growth cycle in this experiment to determine whether or not the plant’s location in relation to the light will affect its height and width. The placement of the plants in the racks will be randomized using a random number generator. The pots will need to be placed equidistant from each other and fill up the entire rack so they are not equidistant from the LED lights.

it is probably one of the factor that could effect the result. In addition, according to the second graph. In week four, the number of leaf on the plant

The point where the fronds were highest in population was between 5/22/2015 to 5/26/2015, with 14 fronds present. On the final day of the testing period, the pH 5 tubes had 13 fronds, which was the highest population outcome of all the tubes. The pH 6 tubes’ population growth was not stable. At the start, there were 6 fronds and it increased up to 8 fronds (on 5/13/2015), but it decreased after that. On 6/1/2015, it was able to grow again up to 3 fronds and then to 5 fronds the day after. The pH 7 tubes’ population seemed constant staying around 8 or 9 fronds between the dates 5/15/2015 to 5/26/2015. The ‘control’ test tube could be considered the most stable of all the tubes because it didn’t have a time period where the population increased or decreased significantly. The only time the number of fronds decreased was between dates 5/26 to 5/28, losing 2 fronds. From the start of this experiment, the control tube’s population steadily increased with 9 fronds as the

For this experiment, student acquired two clean 250-mL Erlenmeyer flasks and 75-mL glass tubes as well as labeled one tube as Tube #1 the second tube as Tube #2. The student utilized the test tubes as photosynthesis compartments. Next, student used 225mL of tap water to fill each Erlenmeyer flask previously attained. Student used 75mL of treatment solution to fill Tube #1 and Tube #2 and placed both tubes in one of the water filled 250mL Erlenmeyer flasks, the water acted as a control variable for temperature change throughout the experiment. Student acquired 2 aquatic plants from the front bench and poured water from the container, which held the plants. It was mandatory for the aquatic plants to be composed of healthy, green leaves and

There was very little change in plant height in either the control groups or the experimental groups. The control group’s plants both died at seven week while the experimental group lived three weeks longer.

Further evidence of this can be observed in Figure 2, exhibiting that the standard deviation increased as well as the mean dry weight along with the CO2. The t-test results in table 2 show that the probability results for the initial and Low weight (0.6501) is above 0.05, therefore establishing the indication that the weight between the two sets of data have significantly less differences, thus being more likely due to chance. However, the t-test results for the Low and Normal weight (4.895 x 10-5), Normal and High seedling weight (8.964 x 10-8) and Low and High seedling weight (2.291 x 10-9) are below 0.05, illustrating that their figures are not due to chance alone. It is clear that the difference between the results of the Initial Seedling weight and the High CO2 seedling weight should be significant, further confirming that as the concentration of CO2 intensifies so does the weight of