Logbook
Week 1
Monday
I will do a trial run on the caffeine affect hear rate of daphnia experiment, to see if I need any
improvement area of improvement and weather, I can carry out the experiment well
Equipment:
Caffeine solution, distilled water, microscope, stopwatch, Petri dishes, pipettes and cotton
Variables:
Control variable: microscope
Independent variable: the concentration of caffeine, the daphnia used
Dependent variable: the heart rate
Method
Using a pipette, I transferred a small number of daphnia into a beaker
I then used the same pipette to extract 1 daphnia from the beaker and placed it into a Petri
dish
I placed the positioned the daphnia under a light microscope to monitor the heart rate
I first counted the daphnia heart rate before the caffeine solution was added to know it
control group
Then using the same daphnia, I added 0.03% of caffeine and measured the heart rate
Then using a cotton, I removed all the liquid then quickly all the 0.05% caffeine solution and
measure the heart rate. This was done using a timer at to measure 1 minute
Repeat step 6 again for the 2% caffeine solution
Repeat the whole experiment 3 times using different daphnia to make it more reliable,
making sure to record it in a suitable table and work out the average
Result:
Caffeine Test 1 Test 2 Test 3 average
solution
concentration
0 28 21 30 29
0.03 35 45 32 33.5
0.5 45 58 49 47
2 58 85 59 58.5
The results gotten from the experiment contains some pretty anomalous result so there, there
should be changes to the method that I should use to gain some consistent result. There may also be
human error when doing the practical such as miss counting of heartbeat, contamination of caffeine
solution, etc
, Risk assessment
hazard risk Safety precaution In emergency Risk level
biohazard contamination Use disinfectant Seek assistance low
after handling
daphnia and
pond water
Broken glass Cuts from broken Be cautious while Apply pressure low
glass handling glass and seek
and stay away assistance from
from edges supervisor for
medical need
Ethical concerns
Animal welfare should be considered which should include, housing and feeding
Daphnia are living organisms so it should be treated with respect and care
Thursday
I will research areas I think I need improving on a so that I can obtain a much more accurate and
detailed results in the main experiment.
Should I have increased the range of the caffeine solution?
In the experiment testing the effect of caffeine on the heart rate of Daphnia, the decision of whether
to increase the range of caffeine concentrations depends on the research question and experimental
goals. A narrow range of concentrations, such as the one used in the original experiment, may not
provide enough information about the relationship between caffeine concentration and heart rate.
Increasing the range of concentrations could potentially provide more insights into the dose-
response relationship, allowing the determination of the threshold and maximum concentrations at
which caffeine affects the heart rate of Daphnia.
However, using a wider range of concentrations may increase the variability in the data and require
more replicates, increasing the cost and time needed for the experiment. Moreover, high
concentrations of caffeine could lead to toxic effects on Daphnia, which should be considered when
choosing the concentrations to test.
Should I have changed the perish to prevent caffeine?
Petri dishes can easily accumulate contaminants from previous experiments or handling, which can
affect the results of the current experiment. Changing the petri dish after each use of the caffeine
solution can help prevent the accumulation of contaminants and ensure that the results are accurate
and reliable.Additionally, it is also important to sterilize the petri dishes properly before use, using
techniques such as autoclaving or exposure to UV radiation, to further minimize the risk of
contamination.
Week 1
Monday
I will do a trial run on the caffeine affect hear rate of daphnia experiment, to see if I need any
improvement area of improvement and weather, I can carry out the experiment well
Equipment:
Caffeine solution, distilled water, microscope, stopwatch, Petri dishes, pipettes and cotton
Variables:
Control variable: microscope
Independent variable: the concentration of caffeine, the daphnia used
Dependent variable: the heart rate
Method
Using a pipette, I transferred a small number of daphnia into a beaker
I then used the same pipette to extract 1 daphnia from the beaker and placed it into a Petri
dish
I placed the positioned the daphnia under a light microscope to monitor the heart rate
I first counted the daphnia heart rate before the caffeine solution was added to know it
control group
Then using the same daphnia, I added 0.03% of caffeine and measured the heart rate
Then using a cotton, I removed all the liquid then quickly all the 0.05% caffeine solution and
measure the heart rate. This was done using a timer at to measure 1 minute
Repeat step 6 again for the 2% caffeine solution
Repeat the whole experiment 3 times using different daphnia to make it more reliable,
making sure to record it in a suitable table and work out the average
Result:
Caffeine Test 1 Test 2 Test 3 average
solution
concentration
0 28 21 30 29
0.03 35 45 32 33.5
0.5 45 58 49 47
2 58 85 59 58.5
The results gotten from the experiment contains some pretty anomalous result so there, there
should be changes to the method that I should use to gain some consistent result. There may also be
human error when doing the practical such as miss counting of heartbeat, contamination of caffeine
solution, etc
, Risk assessment
hazard risk Safety precaution In emergency Risk level
biohazard contamination Use disinfectant Seek assistance low
after handling
daphnia and
pond water
Broken glass Cuts from broken Be cautious while Apply pressure low
glass handling glass and seek
and stay away assistance from
from edges supervisor for
medical need
Ethical concerns
Animal welfare should be considered which should include, housing and feeding
Daphnia are living organisms so it should be treated with respect and care
Thursday
I will research areas I think I need improving on a so that I can obtain a much more accurate and
detailed results in the main experiment.
Should I have increased the range of the caffeine solution?
In the experiment testing the effect of caffeine on the heart rate of Daphnia, the decision of whether
to increase the range of caffeine concentrations depends on the research question and experimental
goals. A narrow range of concentrations, such as the one used in the original experiment, may not
provide enough information about the relationship between caffeine concentration and heart rate.
Increasing the range of concentrations could potentially provide more insights into the dose-
response relationship, allowing the determination of the threshold and maximum concentrations at
which caffeine affects the heart rate of Daphnia.
However, using a wider range of concentrations may increase the variability in the data and require
more replicates, increasing the cost and time needed for the experiment. Moreover, high
concentrations of caffeine could lead to toxic effects on Daphnia, which should be considered when
choosing the concentrations to test.
Should I have changed the perish to prevent caffeine?
Petri dishes can easily accumulate contaminants from previous experiments or handling, which can
affect the results of the current experiment. Changing the petri dish after each use of the caffeine
solution can help prevent the accumulation of contaminants and ensure that the results are accurate
and reliable.Additionally, it is also important to sterilize the petri dishes properly before use, using
techniques such as autoclaving or exposure to UV radiation, to further minimize the risk of
contamination.
