Date: 3rd April 2002
Name:
Rate of Photosynthesis
Question
What do you think the rate of photosynthesis will be when the plant is exposed to green
light compared to the rate of photosynthesis when the plant is exposed to white light?
Hypothesis
According to some information about photosynthesis that we learnt in the class, we all
know that the rate of photosynthesis depends on colours of light and when a plant is
exposed to light, it undergoes photosynthesis and aerobic cellular respiration at the same
time. I predict that the rate of photosynthesis of Elodea when is exposed to white light
will be higher than the rate of photosynthesis when the plant is exposed to green light.
The reason is because white light is brighter than green light so that white light has more
abilities to give light to the Elodea in the test tube.
Comment: This is not the
reason, but it’s good that you
attempted to provide a possible
reason!!
Design
Comment: This section is to be
a summary of what you did, not
just a restatement of the purpose!!
Overall, this lab is investigating the changes in the rate of photosynthesis of the plant
called Elodea, when it is exposed to different condition of light.
Material
Please refer to the file named “Photosynthesis lab.doc” given by Ms. Johnson on T: Drive
Procedure
Please refer to the file named “Photosynthesis lab.doc” given by Ms. Johnson on T: Drive
Comment: Actually the table
belongs in your analysis, while
the graph is your
observations..what happened to
the graph?
Observations
* To find the rate of photosynthesis per hour, please multiply with 8.57 because we
only did each lab for 7 minutes.
Data Table 1: White Light
Item
Value
Maximum Pressure (White Light - Run #1)
10.7 kPa
Minimum Pressure (White Light - Run #1)
10.7 kPa
Net Change – Photosynthesis (White Light)
0 kPa
Maximum Pressure (no light - Run #2)
1.0 kPa
Minimum Pressure (no light - Run #2)
0.1 kPa
Net Change – Aerobic Cellular Respiration (no light - Run #2)
0.9 kPa
Gross Change - Photosynthesis (White Light)
0.9 kPa
Rate of Photosynthesis – White Light (per hour)
7.713 kPa/hour
Data Table 2: Green Light
Item
Value
Maximum Pressure (Green Light - Run #3)
5.7 kPa
Minimum Pressure (Green Light - Run #3)
0.1 kPa
Net Change – Photosynthesis (Green Light)
5.6 kPa
Maximum Pressure (no light - Run #4)
4.6 kPa
Minimum Pressure (no light - Run #4)
0.1 kPa
Net Change – Aerobic Cellular Respiration (no light - Run #4)
4.5 kPa
Gross Change - Photosynthesis (Green Light)
Rate of Photosynthesis – Green Light (per hour)
10.1 kPa
86.557 kPa/hour
Analysis
According to observations, my hypothesis does not agree with the observations because
the Gross Change of Run#3 and 4(Green Light) has the higher value than the Gross
Change of Run#1 and 2 (White Light).
Evaluation
The procedure and materials given from the teacher are precise enough to do this lab
thoroughly. However, I am not really accustomed to use the Low Pressure Sensor so I
think I may make some mistakes while I was recording the data. Expect my weakness in
using Low Pressure Sensor, the lab that I did is adequate enough is figure out the correct
results.
Comment: There were some
additional questions that you were
asked to answer!!
PLANNING..Level 3+;
OBSERVATIONS – graph not
included; ANALYSIS –Level 3;
Evaluation – Level 3