Introduction
Daphnia are planktonic crustaceans2, more commonly known as a water flea. They are microscopic and most commonly found in ponds or lakes. These fleas have flat leaf-like legs that help them move through the water2. Male Daphnia are smaller than female but have larger antennules and their first legs have hooks that are used for clasping2. In spring and summer female Daphnia are more commonly found than male1. Female Daphnia can fertilize without male1. A male Daphnia is more common in fall and winter months while they fertilize egg for the spring1. Our objective was about understanding the scientific method, and we used the Daphnia to do this. The goal was to look at the affect caffeine and ethanol would have on a Daphnia’s heart
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rate. The prediction was that both the caffeine and the ethanol would both have a dramatic affect on the heart rate, the caffeine would speed up the heart rate and the ethanol would slow it down.
With a higher percent of either, there would be a greater affect. Daphnia’s hearts are located dorsally with an open blood circulation, and have about 200 beats per minute2.
Material and Methods
This research steps are found in an organismal diversity lab manual, in the chapter scientific investigation using Daphnia written by P.J. Castle and G.S. Paulson. To start the research, the the group of investigators set up the microscope that will be used to look at the specimen at room temperature around two O’clock in a lab at the Franklin Science Center at Shippensburg University. Carefully the Daphnia was placed on a depression slide that was then prepared to be used, but made sure to not kill it. Once the slide and the microscope was set up the researchers examined the organism
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looking at all the small details. Then found the heart rate. The sources say that each group of researchers must do all four different treatments, there was some changes in how the procedure, and all that had to be done was look at one treatment and compare to the other researchers’ treatments. The next goal was to find the heart rate of the Daphnia after it had been in 0.01% of ethanol for five minutes, this was done to make sure that it was in their system and in full effect.. This procedure was done twice and data was collected both times, while researchers did this, other researchers look at either the affects on the same amount of ethanol, 0.005% ethanol or 0.01% caffeine and 0.005% of caffeine, then compared results. This particular Daphnia were provided for all of the researchers, to preform this three different Daphnia were used. With all the information collected, all raw data was put in excel and excel formulas were used to find, Standard deviation, minimum and maximum, percent change and standard error. With this information another chart was created that showed a t-test and a t-Critical to show if the data is significant. Results This specific group of Investigators collected the data for the affect of 0.01% ethanol on a Daphnia’s heart rate, but received the data for the other treatments, and also received data from the same treatments to compare their results to.
The overall average of the control Daphnia’s heart rate is 249.38 bpm. 0.01% caffeine’s average is 327.93 bpm, and the caffeine at 0.005% has an average of 268.90 bpm, both making the heart rate speed up. Ethanol had the opposite affect, 0.01% ethanol’s average heart rate for this experiment is 159.58 bpm and 0.005% ethanol had an average of 183.4 bpm. Caffeine has a positive percent change while ethanol has a negative percent change in the data chart. The percent change for 0.01% caffeine is 31.50%change, for 0.005% of caffeine it is 7.83% change and for ethanol 0.01% it is 36.01% change while 0.005% ethanol has a 26.47% change. The standard deviation for the treatments all relatively close. Caffeine 0.01% had a standard deviation of 49.77, 0.005% caffeine’s standard deviation is 58.95. The standard deviation for 0.01% ethanol is 54.19, ethanol 0.005 had a standard deviation of 49.47, and the control groups is 33.31. The p-tests show if and how significant the data
is.
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.
The procedure starts with the preparation of the frog and the set-up of the equipment. During the remainder of this lab, continuous
Data table 1 Well plate Contents Glucose concentration A 3 drops 5% sucrose + 3 drops distilled water Negative B 3 drops milk+3 drops distilled water Negative C 3 drops 5% sucrose +3 drops lactase Negative D 3 drops milk +3 drops lactase 15+ E 3 drops 20% glucose +3 drops distilled water 110 ++ Questions B. In this exercise, five reactions were performed. Of those reactions, two were negative controls and one was a positive control.
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
Over a three week period a test subject was instructed to come to the exercise physiology lab once a week. The purpose of the first week was to determine the baseline test data for the participant. During this first week, the subject was asked how many hours of sleep they had gotten the night before and how much they weighed. The subject was then instructed to put on a heart monitor and wear an O2 apparatus and begin running on a treadmill. This treadmill was set at zero incline for the beginning of the run until three minutes had passed. At the three minute mark the incline increased by 2.5%. After this the incline was continuously increased by 2.5% every two minutes. During this process, the VO2 and RER exchange rate of the subject was being tracked through the O2 apparatus. Their heart rate was recorded every 15 seconds. In addition, the subject was asked their perceived exertion at every increase in incline. The subject continued to run until they could not run anymore, at this time they would hop off the treadmill.
On the container, the researchers wrote down their first initial, last name and lab section. The researchers then poured spring water into the cylindrical container about halfway and then set it aside. Next, the researchers transferred the Planarian using a small plastic pipette into an empty petri dish filled with just enough water for the Planarian to swim around freely. After the successful transfer into the petri dish The researchers then measured how long the Planarian was using the unit millimeters.
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...
For this experiment the null hypothesis is that the intensity of the step rate test (High and Low) has no effect on the persons’ heart rate and recovery time. While the alternate hypothesis is that the intensity of the step rate test (High and Low) has an effect on the persons’ heart rate and recovery time.
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.
It was placed on a slide, a couple drops of water was placed on the slide to keep it moisturized. Next, we used a microscope to observe the heart beating in the transparent animal. According to the lab report on page 98 the normal heartbeats are about 350 per minute. By using a pencil and paper, we made a small dash for every heartbeat over a 15 second interval. Than we continued to repeat the observation of the heartbeats 3 more times for a total of 4 observations. We than totaled up the number of dashes and calculated the average of the four 15 second observations, this was labeled “Normal Heart Rate” on Table 1. Next we added 1 drop of an “unknown” solution that was assigned, we made sure to determine the average normal heart rate before doing do. The same procedure outlined above was conducted. The records were than placed in table 1. We than used water in replace of the unknown solution. The same procedure was conducted, we analyzed whether the Daphnia had recovered or not. Lastly our records were compared among our
The goal of this experiment is to see if more college students prefer Diet Coke or a bargain brand Diet Coke. A single blind taste test was given to everyone in the class to determine which soda they like better. A Bernoulli distribution was used to determine which brand was conducted to each participant first. This process insures that the samples given to the subjects are random as possible and to cut any bias. The participants were given the two random samples and were asked to tell which was liked better. The results of this test were recorded then analyzed. From the data, the statistic of people who preferred the Bargain brand was 6/20. This means that the majority of the subjects preferred the real Coke brand over the Bargain brand. A hypothesis test was conducted to test the hypothesis that Diet Coke and a Bargain brand coke are equally
Planning Firstly here is a list of equipment I used. Boiling tubes Weighing scales Knife Paper towels 100% solution 0% solution (distilled water) measuring beakers potato chips Cork borer. We planned to start our experiment by doing some preliminary work. We planned to set up our experiment in the following way.
First we placed the slide under the simple microscope and observed it at ten times magnification level. We each took turns looking. We then copied them as drawings into our Cornell notebooks. After that we changed the magnification to fifty times and observed the slide. We each took turns looking. We then copied what we saw into our Cornell notebooks. After that we changed the magnification level to sixty times and we each took turns looking at the slide. We then copied what we saw into our Cornell notebooks and sat down together. When we were all done drawing we spoke about what we seen and gave each other ideas on how to write our Lab Reports.
As a result, we have to report the t-value by selecting the second line of the table. (d) In this case study, the Mann-Whitney U Test could be used to address this question. Using for independent samples, the non-parametric alternative to the t-test is the Mann-Whitney U Test. Rather than using the t-test to compare means of the two groups (males and females), we can compare medians by using the Mann-Whitney U Test. The Mann-Whitney U Test can be used for differences between two independent groups (males and females) on a continuous measure (the number of coffee consumption a week). Using this method, one can convert the scores on coffee consumption to ranks across the two groups (males and females). There are several key points that can be addressed here. For example, we are considering how males and females differ in their consumption habits of coffee on a weekly basis. Another point is do females have higher consumption of coffee habits a week than males? Therefore, we can evaluate whether the ranks for the two groups (males and females) are a statistically significant difference or not. (a) In this case, it is important to know that the two-way ANOVA method can be addressed in this