Excerpted from The Complete Idiot's Guide to Science Fair Projects © 2003 by Nancy K. From the moment it begins beating to the moment we die the heart works non-stop beating an average of 72 beats per minute, 37,843,200 beats per year and 2,838,240,000 beats per average lifetime1. A birth defect can happen if 56-87 cups of caffeine are taken in all at once. These will be for holding your experimental and control groups before testing. The shrimp were examined using the video screen microscope available in lab and manual counters were used to count the heartbeat. A few other symptoms are drowsiness, yawning, nervousness, depression, etc.
Middle Continue doing so until all volume samples have been drunk. If caffeine is consumed 30-60 minutes before going to sleep, it can cause restlessness and trouble getting to sleep. Ask your subject to drink it as quickly as possible. It is better to underfeed than overfeed. Don't worry about having to learn how to take a crustacean's pulse: you can actually see the heart beating under a microscope. For example, a total of 100mg of caffeine should have been used, which meant that a total of about 4600ml of energy drink would need to be drunk.
On the plus side, they are fairly easy to keep, easy to study, and inexpensive. Non-coffee drinkers tended to be younger 57. Subjects mean age was 60±11 years. Find the average heart rate with a 1% solution. Error bars correspond to 95% confidence interval. .
Difficulty Time Required Average 6-10 days Prerequisites You will need a microscope for observing Daphnia closely enough to monitor heart rate. Distilled water- or tap water left out for 48 hours- is also inexpensive. Unless you are specifically interested in the physiology of crustaceans and there's nothing wrong with that! For example, a random error such as not tapping the pen in the rhythm of the heartbeat affected the number of heart beats per minute. This may be case where it is difficult to actually photograph Daphnia- ask you science teacher if she has a microscope camera. The caretaker in Tale Tell Heart was insane because he acted like he was insane. Teaching notes Daphnia is poikilothermic, which means that its body temperature and therefore its metabolic rate are affected directly by the temperature of the environment.
An experiment conducted by Celenza et al. This introduces bias into the experiment and can distort the results! Work out any mean values from your repeats. Daphnia are crustaceans, commonly found in ponds and lakes and widely sold as live fish food. The increase in this neuronal stimulation is interpreted as an emergency in organisms causing adrenaline to be released therefore heart rate increases. Results: The results you get will depend strongly on what subjects you used for your study. Caffeine is a stimulant, a class of drugs that increase your heart rate and make you more energetic.
This may not have been possible as drinking that much energy drink isn? Exercising would cause the heart rate to increase, with or without the benefit of caffeine. We also seek to establish a baseline for further study of the ghost shrimp. Pharmacists are the medication experts. Then you replay the video in slow motion and count the heart beats again. The variation in caffeinated and decaffeinated coffee could have been caused by systematic errors. I also learnt to not use the slide covers as they kill the Daphnia Analysis The mean heart rate of Daphnia shrimp placed in solution B is 26. The amount of caffeine that they got to drink was not nearly enough to give me a pattern.
Keep in mind that is entirely possible that your curve will look different from all three of the curves in Figure 2. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. Aim: In this experiment we are trying to find out how varying the concentration of caffeine can affect the heart rate of Daphnia shrimp. Repeats can then be carried out with two other Daphnia. This effect applies to the researchers, too.
Although they are simple organisms that may not 'suffer' in the same way as higher animals, they still deserve respect. The heart beat of Daphnia is very rapid, so count the beats by making dots on a piece of paper in the shape of a letter S. By reducing the ability of platelets to adhere to damaged blood vessel walls, aspirin reduces the chance of coronary artery thrombosis, the event that precipitates a heart attack. These animals are fascinating objects for observation and study in their own right. Finally, Daphnia are transparent and so the heart is visible, which avoids the need for dissection. Five daphnia were then placed in each container for ten minutes. Where can the materials be found? Non-coffee drinkers group 1 were compared to subjects who had consumed coffee within 12 to 24 hours group 2 or more than 24 hours group 3 prior to regadenoson administration.
The effect is to increase the rate of ejection of blood by the heart. Caffeine is a central nervous system stimulant meaning it increases the amount of neurotransmitters released meaning coffee is a stimulant that affects the central nervous system by increasing its activity. There are several possibilities for error that could have led to this outcome that must be taken into account. Controlled variables The person taking the heart beat of the person doing the experiment The same person will be used so that the experiment stays accurate. The data can be used to calculate an average, which makes the experiment more accurate. So if she drinks 4-28 cups she will not have an effect.
Allow the Daphnia some time to acclimatise, but keep a check on the temperature of the water in the dish and add more hot or cool pond water if necessary to adjust the temperature. In a randomized, placebo-controlled, double blind and crossover pilot study of healthy subjects, Gaemperli et al. Caffeine is a compound found in especially tea and coffee plants and acts as a natural pesticide. The relationship between adenosine receptors and caffeine makes it possible to hypothesize that heart rate will decrease or be unaffected as the concentration of caffeine increases, which differs from the initially proposed hypothesis and would be a subject for further studies. Daphnia possess a less developed nervous system compared to humans, so they have a reduced awareness of pain. All rights reserved including the right of reproduction in whole or in part in any form.