Daphnia Heart Beats

Their transparent bodies help the experimenters to easily see their pulse. Another reason for choosing this specific organism is their body structure—large surface area to size ratio. This feature allows the substances, such as the household drugs, to easily enter their body which then can affect their health.(1) The household drugs used in this experiment were decaffeinated coffee, tea, instant

After the Daphnia was given time to calm down, the team took a reading of its heart rate at room temperature (27 degrees C). The reading was taken by counting the heart beats for ten seconds and then multiplying by six to yield beats per minute. Next, a glass Petri dish was filled with ice water at five degrees Celsius. The cold water Petri dish was placed on the stage of the microscope, and the Daphnia was placed on top of the dish. When the Daphnia had been given a minute to acclimate to the changes, another heart rate reading was taken. Then the same procedure using the Petri dish to changed environmental conditions was used with cold tap water (23 degrees), warm tap water (30 degrees), and hot tap water (45 degrees). A heart rate reading was taken for each temperature.

To perform this test, a small drop of water is placed on a clean microscope slide. A metal loop that has been properly sterilized in the blue flame and allowed time to cool is used to

Week three the daphnia are tested under different concentrations of an herb to see if the herb causes any types of stress on the variable. All of the same methods are done as in week one and two except in preparing the herbal solutions. To prepare the herbal solution the herb needs to be grinded mixed with methanol and left to sit for a few minutes so it can react and separate the important contents of the herb out. In large clear wells the mixture is measured in microliters of 500, 50 and 5, we also measure out 500 of methanol and all of these are left to dry out. Then 5ml of water is added to 5 wells the four

The five substances are which determined the outcome of the HR of each Daphnia. The methods that were conducted in the lab procedure are as followed: Step one the group got out the microscopes and obtained one depression slide. Using a dropper Chelsea gathered one Daphnia and placed it in the middle of the slide. Step two while the Daphnia was on the slide, Chelsea began to position the microscope to place the slide and the Daphnia in the middle of the lens to get a better view of the Daphnia and its heart. Step three, the group gathered all five substances starting with the sleeping pill.

Due to the miniature size of a Daphnia, biologists have had unique troubles with analysing the way the systems of the Daphnia function. Biologists have argued, that the circulatory system of a Daphnia relies on diffusion or convection. However, it has been decided that depending on the oxygen levels in the environment will affect the way that the circulatory system of the Daphnia functions. The levels of haemoglobin will also affect the functioning of the circulatory system in the water flea. Haemoglobin is a red blood cell, assisting the

I analyzed my Daphnia Magna everyday by observing if the Daphnia were alive or not at the end of each day. I did this by observing if the Daphnia had sunk to the bottom of the container and not moving at all for a long time. For Trial 1, SIXDAYSOX had 2 Daphnia alive while Gmark and Vitalsox only had one alive. For Trial 2, on Day 1 all the sock brands started out well and all four Daphnia survived. On Day 7 of Trial 2, Vitalsox had two Daphnia left while Gmark and SIXDAYSOX had only one alive.Also for Trial 2 one of the 4 control Daphia had died. For Trial 3, Gmark and SIXDAYSOX both had 4 Daphnia left while Vitalsox had three remaining. On Day 7 of Trial 3, Gmark had no Daphnia alive while SIXDAYSOX and Vitalsox both had one remaining.

To begin the experiment, we took a single Daphnia magna from the unused tank to run control tests with distilled water on the untampered heart rate of the species. The species was placed on a concave slide with a new drop of water on it. It was given 2 minutes of recovery time to adjust to its new environment; then, the heart rate was studied by intervals of 15 seconds to find beats per minute by multiplying the number of beats in 15 seconds by 4. The Daphnia magna was studied under a light microscope with 40x total magnification. After each round of data collection, the water was absorbed with a Kimwipe so a new water drop could be placed on the species. The same Daphnia magna was used for six rounds of control experiments. After

My hypothesis was supported in the experiment due to the fact that caffeine raised the beats per minute, while kava drastically decreased the amount of heart beats in a given minute. By looking at figure 1 you are able to see that kava decreased the heart rate by -46 beats per minute, while the caffeine raised the beats to 26 per minute. This supports the conclusion that the stimulation humans receive off of caffeine has a similar effect in Daphnia Magna. Caffeine raises the beats per minute in each individual, while kava decreases the amount of beats. This is due to kava’s relaxation properties found within it’s roots commonly called kavalactones. I assumed that the effects of caffeine and kava on humans would be similar to those of Daphnia

The effects of MP exposure on life history parameters were tested in a 21-d reproduction test according to OECD guidelines at one concentration of each particles size: 1000 particles/L (0.1,1,10 µm), subjected to the environment concentration about 1.1 items/mL has been reported(Moore et al., 2011). In brief, there were triplicates for each control and treatment group an experimental series. Five neonates (< 24h) were incubated respectively in 50 mL medium at 22 ℃ under a 12:12 light dark cycle of 1600 lux and fed 4.2×104 cell/mL a day of the micro alga Chlorella vulgaris. The test medium was fully replaced every day along with calculating the cells of C.vulgaris the daphnia ate everyday by blood cell

The ACh was a stimulant. The five-hour energy was a stimulant. The aspirin was a depressant. The diet pill was a stimulant. The substance with the strongest effect was the Adrenaline. The group’s predictions were all accurate according to the data we obtained in this lab. Doing this lab was a great way to learn what these substances do to your heart and your body. These results could always be from a human error but the group was confident with the labs result. The group was confident that the lab was done correctly and efficient. One of the issues the group could have had is the amount of time we had to do the lab and it was hard to keep up with the Daphnia’s heartbeat. Another human error could be that we put too much of the substance on the Daphne and didn’t keep a close eye on the stopwatch. For further research we could always test different stimulants and

An error that occurred during within this lab experiment was not weighing the beaker at the same, tampering with the results. There was chaos within the first beaker it could not be be put on the plastic balance. Making a quick decision that was not in the procedure, which was wait 3 and half mins before weighing the becker instead of 1 min after boiling out water and the cardondixode gas out. this caused the lab experiment to had a later start time. The time of weighing the sodium acetate was effect within this error caused the results to be different.

Both temperature and chemical changes to the environment were observed to effect the daphnia’s heart rate. Increasing water temperature

(3)Place under microscope but remember to not leave it under the light for too long, which could result to heating the Daphnia or difference in temperatures.

To secure the sensor a constant amount of putty was placed abound the opening of the tubes, this also ensured that the water would not flow out during the trials. The “body” of the butterfly was then taped to the center of the underside of each butterfly. The entire butterfly was clamped at 4 inches from the light source (90-watt light bulb), which was clamped to the top of the ring stand. The butterflies remained under the light bud for ten minutes, during this this time the sensors collected data 6 times per minute. This was done a total of thirty times, ten trials per butterfly.