Introduction
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
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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 …show more content…
The chemicals as well as temperature represent environmental change that affected the heartbeats. It was later revealed that Unknown #1 is Caffeine and Unknown #2 is Ethanol. A stimulant, like caffeine, is a drug that excites the central nervous system and increases alertness. The results for caffeine (Unknown #1) showed direct impact in trial #2, the number increase from 50 (trial #1) to 53 (trial #2). The results in the graph show a positive correlation between caffeine and the heart rate of Daphnia. Caffeine is the stimulus in this experiment because it inhibits the action of the enzyme, resulting in an increased intracellular concentration while ethanol works by inhibiting the action of the neurotransmitters that transmit nerve impulses across a
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.
Planarians are free-living, carnivorous flatworms found in the Phylum Platyhelminthes, Class Turbellaria. Although the Phylum Platyhelminthes is known for having the animals with the most parasitic species, the class Turbellaria which consist of the Planaria, are a non-parasitic species. Platyhelminthes which translates to "flat worm" are triploblastic animals. This means that they have three tissue layers, the endoderm, mesoderm, and ectoderm. Planaria also are monoecious organisms, meaning that they have both female and male sex organs in one organism. Another characteristic of the Planaria is that they do not have a true body cavity, meaning that they are acoelomate organisms.
Also, we learned that depressants decrease the heart rate because they influence the parasympathetic nervous system which responsible for the rest and digest and depress the sympathetic nervous system (Silverthorn, 2010). The main stimulator in Red Bull is caffeine, it functions by blocking the effects of the adenosine, a brain chemical involved in sleep. When caffeine blocks adenosine, it causes firing of neurons that stimulate the sympathetic system, that triggers "fight or flight" response by releasing adrenaline. Adrenaline is a hormone that increases the heart rate and dilate the eye; another effect of Caffeine is changing the levels of dopamine, responsible for pleasure in the brain (Kollmorgen, 2011). We will be comparing the components individually to the baseline, we will also be testing the components in combination compared to their results individually and baseline. Our baseline will be aged tap
· The daphnia will be submersed in the water and left to equilibrate for 3 minutes, after this time one of the Daphnia will be removed and put onto a microscope slide, this will then be quickly put under the microscope. -1- · Under the microscope, the Daphnia will be observed for 20 seconds, this heart rate will be counted and recorded, this can the be
The procedures for this experiment are those that are referred to in Duncan and Townsend, 1996 p9-7. In our experiment however, each student group chose a temperature of either 5 C, 10 C, 15 C, or 20 C. Each group selected a crayfish, and placed it in an erlenmeyer flask filled with distilled water. The flask’s O2 levels had already been measured. the flask was then placed in a water bath of the selected temperature for thirty minutes, and then the O2 levels were measured again. Each group shared their findings with the class. The metabolic rates of the mouse were conducted by the instructor and distributed. We also did not use the Winkler method to measure the O2 levels. We used a measuring device instead.
Caffeine, a central nervous system stimulant, is the main psychoactive ingredient in energy drinks, which enhances alertness and mood, and counteracts symptoms of sleep. There is no doubt ...
minutes, the AHR escalated even more, to 369 bpm. See Table 5 and Figure 3.
Abstract: The human brain is the most complex organ in the body. Its functions control every aspect of life. It is important to attempt to comprehend the workings of the brain and to learn the effects of natural and unnatural substances on it. In order to look at chemical effects on the brain, one must first get an understanding for the chemicals as well as how the brain works to interpret and react to signals set out by these chemicals, rhythmically and physiologically. Several chemicals observed include: cocaine (and other chemicals), seratonin, and melatonin.
The data for my experiment showed that as time went by the heart rate increase followed by a major decrease known as a crash. A crash occurs when your heart rate increases so fast all at once that when the caffeine’s effect wares off the heart rate drops rapidly. Energy Drinks are known to give you energy, but part of the agreement that comes with consuming these types of drinks is being ready for the consequence. Some consequences are more severe than others. My hypothesis was proven to be correct. Your heart rate does increase over time due to the amount of caffeine the energy drink
This system operates through the release of various neurochemical transmitters (from the nerve cells in which they are produced) and their binding to receptor sites on neighboring cells. The constant release and binding of these neurotransmitters forms a pathway of “messages” that travel throughout the body, sustaining life and making possible the organism’s response to environmental stimuli. The drug also has an impact in the autonomic (or involuntary) division of the central nervous system, which helps regulate a variety of bodily functions that are generally free of volitional impact, including respiration, circulation, digestion, and body temperature. Ordinarily, these functions are maintained at relatively stable levels throughout the day. But they are slowed down during periods of rest through diminished production, release, and binding of neurotransmitters and can be speeded up, as needed, through increased neurotransmitter activity. It operates in the system by increasing the concentration and binding activity of the body’s own neurotransmitters, particularly dopamine. Thus, what people experience as the stimulant effect is an intensification of the body’s normal stimulatory mechanisms. (Pharmacodynamics: Cocaines Interaction with the Human Organism,
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 isomerization procedure was done in order to create dimethyl fumarate from dimethyl maleate. Dimethyl maleate and dimethyl fumarate are cis and trans isomers, respectively. This procedure was done via a free radical mechanism using bromine. The analysis of carvones reaction was done in order to identify the smell and optical rotation of the carvone samples that were provided. The odor was determined by smelling the compound and the optical rotation was determined using a polarimeter.
The purpose of this experiment was to gather data on how the amount of time spent active impacts the speed of heart rate in beats per minute. The hypothesis stated that if the amount of time active is lengthened then the speed of the heart rate is expected to rise because when one is active, the cells of the body are using the oxygen quickly. The heart then needs to speed up in order to maintain homeostasis by rapidly providing oxygen to the working cells. The hypothesis is accepted because the data collected supports the initial prediction. There is a relationship between the amount of time spent active and the speed of heart rate: as the amount of time spent active rose, the data displayed that the speed that the heart was beating at had also increased. This relationship is visible in the data since the average resting heart rate was 79 beats per minutes, while the results show that the average heart rate after taking part in 30 seconds of activity had risen to 165 beats per minute, which is a significantly larger amount of beats per minute compared to the resting heart rate. Furthermore, the average heart rates after 10 and 20 seconds of activity were 124 and 152 beats per minute, and both of which are higher than the original average resting heartbeat of 79.
Preview: The potential effects are related to the main ingredient in coffee – caffeine. Caffeine is a drug that stimulates the central nervous system that increases alertness and energy, but it is also very addictive.