Daphnia Lab

Title: Physiological Changes in the Heart Rate of Daphnia magna When Exposed to Stimulants (Caffeine and Alcohol).

The Daphnia is commonly referred to as the water flea and has been under research by scientists for over a century. Daphnia can be located in and around permanent bodies of water. Daphnia, although can be found in any water, are usually found in freshwater lakes especially near ponds and high vegetation areas. Daphnia are too small to live in strong currents so they branch to ponds and small lakes where they live off plankton.

After completing the experiment we found that when we gave the Daphnia caffeine the heartbeat rate did show an increase. However, we also found that alcohol also increased the number of times the heart beat. Even though we performed all of the experiments very carefully, we cannot be certain that the effect we saw was due to the drugs. Perhaps the change in heartbeat rate is caused by

Daphnia, also known as water fleas, are small crustaceans about 1mm-5mm long and are part of the freshwater zooplankton (Ebert 2005, Hutchinson 2005 & Clifford 1991). Daphnia can be found in most fresh water habitats such as freshwater springs, ponds and reservoirs and are the predominant food for planktivorous fish. Dapnia are ‘filter feeders’ meaning they feed on small particles suspended in the water which can include algae. It has been found that daphnia tend to migrate to the upper parts of the water at night and return to the lower parts of the water in the day to hide from predators (Ebert 2005) (Hutchinson 2005). Daphnia can reproduce through sexual reproduction and also asexual

Daphnia belong to the phylum of arthropod; the subphylum of Crustacea; the class of brachiopod; and the order of Cladocera.

Daphnia Magna will be used to measure how quickly dead zones are forming by eutrophication. We will use three different endpoints to measure the Daphnia Magna: Heartbeat, Mobility, and Mortality. We will have three fertilizers mixed with pond water in three separate test tubes per fertilizer with Daphnia Magna and one without ferilizer as the control. There will be three different sets each set will contain four test tubes: Three test tubes each with different fertilizers and one without as the control. We will then measure the three endpoints of the Daphnia Magna after thirty minutes which will be repeated for each set thus the whole experiment will last 90 minutes. The equipment needed for the experiment is the following:

Table 1 (Figure 3) shows that the control is the lowest in heart rate, from there the heartbeat goes up when the daphnia are exposed to sugar. The difference between the control and the rest of the tests is very large. Although the data is very spread, the averages clearly show a significant difference between the results. The control group clearly showed that the heart rate of a daphnia magna is lower than the other two tests. The solution using the juice had more effect on the heart rate of a daphnia magna than a sugar solution and the control. The two sets of data that were taken with the daphnia exposed to the solutions were very close and shows that both have similar effects on the heart rate, they both increase the BPM of the daphnia

Immersing Daphnia in the ethanol indicated an increase in the heart rate. This relates to the fact that alcohol can have a big impact in the live of humans. Since the cross sectional part of the heart relates to that of humans. The increase in the heart rate enabled me to understand more about the how the increase in the heart rate when ethanol (Alcohol) is present in the body it can affect one's blood pressure [1]. In contrast, high blood pressure is somewhat indicates how one’s heart is beating really fast. This means that at as the heart is pumping blood through the vein and arteries in the body. The force the heart is using to pump the blood through the artery walls can cause a tear or damage of the arteries which can lead to death. Furthermore,

Experiment one tested the concentration of experimental beta blockers, and its relationship with the percent decrease in of the heart rate of the Daphnia. Our goal, was to prove that, an increased concentration of beta blockers would decrease the overall heart rate of the Daphnia being tested. Our results, established, that as the beta blocker concentration increased, so did the decrease in the heart rate of the Daphnia. Experiment two tested two unknown concentrations (A and D) and its effect on the Daphnia to see if it contained any concentration of beta blockers. The results, for concentration A showed very little effect, and concentration D seemed to have no effect on the Daphnia at all. Experiment one shows, that

For this experiment the independent variable is the crayfish and elodea while the dependent variable is the respiration rate measured in NaOH. The elodea and crayfish were placed into two different graduated cylinder containing 30ml and the volume displacement were than recorded. Once finished measuring, three beakers were obtained, labeled and 100ml of tap water was added to each beaker. The control group is beaker 3. The beaker containing elodea was completely covered in foil and placed into a dark cabinet to avoid photosynthesis from happening for 15 minutes. After 15 minutes, the crayfish and elodea were taken out and placed back into their tanks. Four drops of the pH indicator phenolphthalein were added to each beaker. NaOH was dropped

Also tested was the daphnia’s response to chemical changes in their environment. Diphenhydramine is the active ingredient in the common allergy medication Benadryl. In humans, this drug is often used to treat allergy symptoms including itching and hives as well as common cold symptoms like runny nose and excess mucus. Its main action is to block the receptors that the histamine usually bind to and thus inhibiting the action of histamines. I expected diphenhydramine to increase the heart rate because one of the common side effects in humans is increased blood pressure and heightened heart rate. I was also prepared for a decrease in heart rate because diphenhydramine is also know to cause drowsiness (it is also an active ingredient in many common sleep aids) which could indicate that it will the daphnia’s lower heart rate

When working on a heart in-vivo there is the action of both parasympathetic, sympathetic stimulation as well as hormonal control. In a live animal, the heart will continually be indirectly stimulated by nerve impulses that increase or decrease heart rate based on bodily activity. There is an absence of those factors in an isolated heart preparation, thus the heart rate will solely be determined by the sinoatrial node and the external stimuli administered. Activity 3: Examining the Effect of Temperature on Heart Rate Results: Provide the heart rate values recorded when the heart was bathed with Ringer’s solution of different temperatures. (2

Description of Experiment:In this experiment to test the effect of colder temperatures on goldfish respiration rate.We started with a beaker

All materials were obtained to start the experiment. To measure the heart rate after one minute of exposure, 44

From this BIOPAC laboratory, the student(s) should learn how different stimuli will affect a resting heart rate. Due to the fact that cardiac muscle is able to create action potentials on its own, a change in chemical, temperature, and ionic balance causes the heart to react differently and change its rhythm of beats by either slowing down or speeding up. More specifically, by saturating the heart with histamine the heart rate should speed up, while pilocarpine will cause the heart to substantially slow, and finally the addition of epinephrine will cause the resting heart rate to speed up.