Endocrine System

      Every organism’s full contraction and dilation of the heart is different. The way organism’s heart rate changes to different chemical solutions and temperature change is very similar. The purpose of this experiment is to study the effect of water, alcohol and caffeine in the heart rate on the Daphnia. According to existing research and scientific literatures, both of these drugs have similar interactions with animal cells but produce opposite effects.
Daphnia magna or water fleas are small aquatic, transparent organism and they belong to the Phylum Arthropod and it the Class Crustacean. The Daphnia magna is a perfect organism for this experiment because Daphnia are small and they can easily be placed under the microscope, their exoskeleton body is transparent, therefore the heart can be easily seen, they are very sensitive to their environment, therefore they will quickly react to the stimuli, they are cold blooded and easy to keep them in the laboratory and handle them throughout the experiment. The scientific question is: How will the Daphnia magna react to several different stimuli? Daphnia’s heart rate won’t be affected in its natural environment rather be affected by the addition of caffeine. My hypothesis was that as the caffeine increases, so would the Daphnia heart beat. Also, the heart rate is affected by cold temperature change which will decrease the heart rate. The Daphnia will have to be placed in the distilled water to recover its natural habitat, so that the heart rate will be normal again. Humans and water fleas have a common ancestor and we both belong to the Animal Kingdom. As a result of this it’s possible that we will react to neurotransmitters and cold temperature change the same way. Ectodermic animals are animals whose body temperature is affected by their surroundings. When an ectodermic animal is cold, its heart rate will lower.   When the animal is warmer, the heart rate will raise – as long as the...