Hira
Investigating project unit 6 (C+D)
P4+P5+P6+M4+M5
Implemented Method
Hypothesis
I expect daphnia heart rates to decrease with more ethanol and increase with caffeine,
comparing changes during various chemical concentrations.
Null Hypotheses:
My null hypothesis is that there is no statistically significant difference.
Alternative Hypotheses:
My alternative hypothesis is that there is a statistically significant difference.
Controlled Variables:
The duration spent in the solutions.
The use of the same equipment.
Conducting the test on daphnia from the same environment.
Measuring heart rate at the same location.
Independent Variable:
The change in concentration of each chemical.
Dependent Variable:
The change in heart rate of each daphnia in response to varying concentrations of ethanol
and caffeine.
Equipment used
Electric microscope
Cavity slides
Distilled water
Daphnia from the same environment
Ethanol
Caffeine
Pipette
, Syringe
Counter
Petri dish
Pen
Absorbing cloth/ tissue
Logbook
Thermometer
Beaker
Phone to record
Method
The first thing that I did was to take 2 water fleas of the same size and place them
into separate petri dishes in distilled water (the same temperature for all petri
dishes).
Next, I set up the microscope but didn’t turn it until the start of the investigation as
its light could heat up the testing space because it is very important to keep the
temperature of the experiment environment stable for more accurate results.
After that, I started the experiment and picked out the daphnia from the first
container using pipette.
I placed it into an empty petri dish and tried to grab the daphnia with a pipette with
the least water possible, in order to prevent it from moving too much and placed it
on the cavity slide.
During the experiment, I kept the daphnia in only one drop of water so it will stay
alive but will remain immobilise.
I then put the slide under microscope and turned the microscope on.
I made sure that I could see the Daphnia clearly under the microscope, and once I
was happy with the image, I looked for the heart.
Then using a phone, I recorded a video of the heart of daphnia for one minute.
Then, using video editors, I slowed down the video I had shot so that I could easily
count each beat and make sure that the results are accurate.
I recorded the result in the logbook in which I was keeping track of the temperature,
date and time too.
I then repeated this process with all the other water fleas after which I had a table of
results from which I could plot my graph.
I turned off the microscope after each count to prevent further heating caused by the
light.
For each daphnia I carried this experiment first with water only and then with
different concentrations of ethanol, starting from lower concentration to high, so I
could be able to compare the difference ethanol makes on the heartbeat.
Investigating project unit 6 (C+D)
P4+P5+P6+M4+M5
Implemented Method
Hypothesis
I expect daphnia heart rates to decrease with more ethanol and increase with caffeine,
comparing changes during various chemical concentrations.
Null Hypotheses:
My null hypothesis is that there is no statistically significant difference.
Alternative Hypotheses:
My alternative hypothesis is that there is a statistically significant difference.
Controlled Variables:
The duration spent in the solutions.
The use of the same equipment.
Conducting the test on daphnia from the same environment.
Measuring heart rate at the same location.
Independent Variable:
The change in concentration of each chemical.
Dependent Variable:
The change in heart rate of each daphnia in response to varying concentrations of ethanol
and caffeine.
Equipment used
Electric microscope
Cavity slides
Distilled water
Daphnia from the same environment
Ethanol
Caffeine
Pipette
, Syringe
Counter
Petri dish
Pen
Absorbing cloth/ tissue
Logbook
Thermometer
Beaker
Phone to record
Method
The first thing that I did was to take 2 water fleas of the same size and place them
into separate petri dishes in distilled water (the same temperature for all petri
dishes).
Next, I set up the microscope but didn’t turn it until the start of the investigation as
its light could heat up the testing space because it is very important to keep the
temperature of the experiment environment stable for more accurate results.
After that, I started the experiment and picked out the daphnia from the first
container using pipette.
I placed it into an empty petri dish and tried to grab the daphnia with a pipette with
the least water possible, in order to prevent it from moving too much and placed it
on the cavity slide.
During the experiment, I kept the daphnia in only one drop of water so it will stay
alive but will remain immobilise.
I then put the slide under microscope and turned the microscope on.
I made sure that I could see the Daphnia clearly under the microscope, and once I
was happy with the image, I looked for the heart.
Then using a phone, I recorded a video of the heart of daphnia for one minute.
Then, using video editors, I slowed down the video I had shot so that I could easily
count each beat and make sure that the results are accurate.
I recorded the result in the logbook in which I was keeping track of the temperature,
date and time too.
I then repeated this process with all the other water fleas after which I had a table of
results from which I could plot my graph.
I turned off the microscope after each count to prevent further heating caused by the
light.
For each daphnia I carried this experiment first with water only and then with
different concentrations of ethanol, starting from lower concentration to high, so I
could be able to compare the difference ethanol makes on the heartbeat.
