The Daphnia magna species in this experiment were kept and preserved in jars of suitable water that acted as small ponds. Each Daphnia Magna was transported individually using a wide-mouthed pipette to a depression slide. The stability of the Daphnia Magna on the slide was attained by using a drop of pond water that acted as a boundary of movement for the Daphnia on the depression slide, small pieces of cotton wool were also used to act as an extra boundary to stop the Daphnia Magna from swimming in circles in the pond drop it was placed in; the stability factor was important in counting the heart beat rate more accurately. The depression slide was then placed under the stereomicroscope, over a cooling chamber that was used to slow down the …show more content…
heart beat speed of the Daphnia Magna, which is usually fast, so that the measurement of the heart beat rate was easier. The cooling chamber had to be filled with enough ice to maintain a temperature between 15-18 degrees Celsius; the temperature was measured using a thermometer. Each Daphnia Magna was given a minute to acclimatize on top of the cooling chamber; until the heart beat speed slowed down. The Daphnia Magna’s were divided into 5 groups with 3 Daphnia Magna’s in each; 1 controlled group and 4 treatment groups.
The controlled group was left with 0 nicotine applied. The 4 treatment groups were treated with 4 different levels of nicotine concentrations: 25 µm, 50 µm, 75 µm, and a 100 µm. The treatment concentrations were applied on top of the pond drop that the Daphnia Magna’s were trapped in on the depression slide; a minute was given for Daphnia Magna acclimation with the treatments. Then, the heart rate of each of the 3 Daphnia Magna’s in the 5 groups was measured, 3 Daphnia Magna’s were tested in each group to attain the mean so that more accurate results were reached. The technique used was that we counted the number of heartbeats in a 10 second interval and then multiplied that number by 6 to attain Beats/min; an initial (before treatment) HBR and after treatment HBR were recorded for each Daphnia Magna. The raw data were written down in a table and were later moved for demonstration on a graph for the final preview. The data collected matched the expectations, for the controlled group: the heart beat rate was dropping slightly (becoming slower), the reason behind that was most likely the cooling chamber because there was no treatment applied or any other external
factors. As for the treatment groups: nicotine increased the heart beat rate of the Daphnia Magna. The bigger the nicotine concentration added, the faster the heart beat rate of the Daphnia Magna became compared to its initial heart beat rate before any concentration of nicotine was applied.
The Artemia franciscana can survive in extreme conditions of salinity, water depth, and temperature (Biology 108 laboratory manual, 2010), but do A. franciscana prefer these conditions or do they simply cope with their surroundings? This experiment explored the extent of the A. franciscanas preference towards three major stimuli: light, temperature, and acidity. A. franciscana are able to endure extreme temperature ranges from 6 ̊ C to 40 ̊ C, however since their optimal temperature for breeding is about room temperature it can be inferred that the A. franciscana will prefer this over other temperatures (Al Dhaheri and Drew, 2003). This is much the same in regards to acidity as Artemia franciscana, in general thrive in saline lakes, can survive pH ranges between 7 and 10 with 8 being ideal for cysts(eggs) to hatch (Al Dhaheri and Drew, 2003). Based on this fact alone the tested A. franciscana should show preference to higher pH levels. In nature A. franciscana feed by scraping food, such as algae, of rocks and can be classified as a bottom feeder; with this said, A. franciscana are usually located in shallow waters. In respect to the preference of light intensity, A. franciscana can be hypothesized to respond to light erratically (Fox, 2001; Al Dhaheri and Drew, 2003). Using these predictions, and the results of the experimentation on the A. franciscana and stimuli, we will be able to determine their preference towards light, temperature, and pH.
In the lab the isopods were observed in a way to where behavior and structures could be properly recorded. The isopods were revealed to two dissimilar scenarios, normal temperature water vs. warm temperature water, to calculate which environment was most preferred. In each distinct scenario ten isopods were placed ten a choice chamber, one side being normal temperature (26.7celsius) and the other being warm temperature (43.3 celsius) , and observed for a total of ten minutes with thirty second intervals which was when we recorded our observations. After observations, it was seen that normal conditions was the most preferred environment by the isopods. In the scenario the Isopods exhibited taxis behavior, which is behavior caused by factors such as light, temperature, water and such. Nothing physical, but rather environmental.
With over nine hundred and seventy one tons, the United States is the country with the highest amount of caffeine consumption in the world. This chemical compound is known to have many affects on our bodies, primarily in our hearts. Caffeine has been shown to increase blood pressure and heart rate. However, as far as scientists know, the affects of caffeine may affect invertebrates differently than it affects vertebrates. The present experiment studied blackworms - Lumbriculus variegatus in the phylum Annelida- in solutions with different amounts of caffeine to see if it affected their pulse under a compound microscope. Worms do not have hearts; they have aortic arches that contract to push the blood into the dorsal and ventral
For further investigation, a larger sample size should be used, along with repeating the experiment on several different days to minimise the effect of random errors on each subject’s specific result. Reference List: BBC 2014, Respiration, BBC, accessed 1 September 2015,.
Polyphemus is a semi-human, man-eating monster with a single eye in the center of his forehead. He was referred to as a cyclops. He is the son of Poseidon and Thoosa, and lives on an island devoted to cyclops. Polyphemus means abounding in songs and legends.
Planaria usually live in water, water doesn’t have any effect on them which the reason why it is used as a control group in this experiment. Planarian will be put near the edge in a two-chamber tray containing water, in the side that is not covered with a dark piece of paper. Five planaria will be tested in a 2- chamber tray. We will measure how long it takes the planaria to move from the edge of a chamber receiving light, to the dark chamber. Subsequently, start by adding the lower concentration of caffeine in the water, replacing planarian in the same position and measuring how long it takes now to go back to the dark chamber in the presence of caffeine. We will duplicate the same procedure with higher concentrations of caffeine and additionally take the average of the time all five planaria took to move from the edge of the chamber in brightness, to the dark chamber in different concentrations of
To begin the lab, the variable treatment was prepared as the Loggerlite probe, used to later measure oxygen consumption, warmed up for approximately 10 minutes. To prepare the variable treatment, 200ml of Sodium and Ammo-lock water was measured in a container and a pre-prepared “tea bag” of tobacco was steeped in the room temperature treated water until a light yellow color was visible. After preparing the tobacco solution the preparation for the live goldfish began as two beakers were filled with 100 ml of treated water. Each beaker was weighed before addi...
In the following experiment, we will attempt to examine the relationship between metabolic rate and environmental temperature in both an ectoderm and an endotherm. I predict that for the ectotherm, the metabolic rate will increase as the outside environment temperature will increase. I also predict that the metabolic rate in the endotherm will remain relatively the same as the outside environment temperature changes. I also make the prediction that the ectotherm will have much lower metabolic rates than the endotherm.
The purpose of this lab was to study the response of the genus Daphnia to chemical stimuli and to examine human responses to different stimuli. A stimulus is an incentive; it is the cause of a physical response. Stimuli can have a physical or chemical change; an example of a physical change is a change in temperature and sound. An example of chemical change would be changes in hormone levels and pH levels. Muscular activity or glandular secretions are responses that occurs when stimulus information effects the nervous and/or hormone system. Daphnia is a genus; it is a small crustacean that lives in fresh water. The body of the daphnia is visible and its internal organs are clearly seen thus it was chosen for this exercise. The
In the short story ”The Noble Experiment”, from I Never Had it Made, by Jackie Robinson as told to Alfred Duckett, Branch Rickey had a magnificent plan to integrate blacks into Major League Baseball, rather than the Negro leagues where many blacks played baseball. Branch Rickey’s quest for the perfect black candidate took him beyond national borders, his search was brilliantly disguised to the public as if he was created a black-baseball league. Rickey said that the ideal candidate,”...had to be able to stand up in the face of merciless persecution and not retaliate”(Duckett 290). When Jackie Robinson met Branch Rickey for the first time, Rickey told Robinson that the opposition would taunt him,
Experiment #1: The purpose of this experiment is to investigate the effects of baking soda and light intensity on the rate of photosynthesis of green spinach leave through the observation of floating disk.
The experiment measured the survival rate, the growth rate, and the size of the brine shrimp at the time harvested in various environments. To obtain these measurements, three environments were created: sea water, brackish water, and freshwater. For this experiment the scientists used 5 liter plastic buckets. Every two days, half of the water from each bucket was discarded and new water, of each respective salinity, was added into each bucket...
The organism Daphnia magna belongs to the phylum Arthropoda, subphylum Crustacea, and the class Branchiopoda (Ebert, 2005). As planktonic organisms (National Science Teachers Association, 1987), Daphnia are found in “freshwater, temperate environments throughout North America” (National Science Teachers Association, 1987). The Daphnia also contains a pair of antenna located at the top of the head that is used as a method of movement (Ebert, 2005). Due to its transparency, the Daphnia is easily visible through a microscope. The nervous system of Daphnia is rather primitive, containing a cerebral ganglion (Ebert, 2005) which is a nerve cluster containing both afferent and efferent nerves (Chase, 2000). Most environmental changes affecting the
The myth “Daedalus” as retold by Anne Terry White, a man learns that his actions have unexpected and unfortunate consequences. Daedalus is a famous and outstanding architect that lives in Athens. The story starts with his nephew, Talus arriving in Athens. One day, while Talus while pondering on the beach, he invents a fish saw and a compass while Daedalus watches. Thus, Daedalus gets extremely jealous of Talus and pushes him off of a cliff, killing him almost instantly. Daedalus is very afraid he may get caught, so he leaves, and wanders, until he reaches Crete. The king of Crete, Minos, hires Daedalus to build a labyrinth. Daedalus realizes he is a prisoner of Minos, but luckily he knows his way out of the labyrinth, considering he built it.