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PURPOSE
The purpose of this experiment was to find out whether different concentrations of chlorine affect the survival rate of daphnia.
I became interested in this idea when I found out that you could see a microorganism's heart beating and experiment with them.
The information gained from this experiment could
lead large companies, municipal water plants, and homeowners to learn that
they are doing damage to the food chain. By polluting the environment
with chlorine, you are killing daphnia, which feed the fish we eat.
HYPOTHESIS
My hypothesis is that as chlorine concentrations increase, the percent of daphnia survival will decrease.
I base my hypothesis on the fact that chlorine is dangerous to human beings. It is known to be fatal if swallowed or inhaled in concentrated amounts according to the manufacturers.
EXPERIMENT DESIGN
The constants in this study were:
The manipulated variable was the amount of chlorine put into the water with the daphnia. The responding variable was the number of daphnia that survived through the experiment. To measure the responding variable I will count the remaining number of daphnia having a heartbeat using a ten power microscope.The temperature of the water The amount of water The amount of daphnia tested The same kind of containers The same type of daphnia
MATERIALS
| Quantity | Item Description |
| 60 | Daphnia |
| 5 | Petri dishes |
| 1 | Gallon Distilled Water |
| 1 | 10xPower Microscope |
| 1 | Set Plastic Tweezers |
| 1 | Pair Rubber Gloves |
| 2 | Eye Dropper |
| 50 | Beads |
| 5 | Graduated Cylinders |
PROCEDURES
1. Prepare all of the necessary supplies and put the safety gloves on.
2. Make the dilutions by adding the prepared 1 ml of chlorine to the prepared 99 ml of distilled water in a graduated cylinder. That was the strongest solution.
3. Then add 10 ml of the previous solution to 90 ml of distilled water in a graduated cylinder. Thus, having the second strongest solution.
4. To make the third least potent solution, add 10 ml of the previous solution to the 90 ml of already prepared distilled water.
5. To make the weakest solution, add 10 ml of the previous to 90 ml of distilled water.
6. Get the dishes out and number them on the bottom one through five, five being the most lethal.
7. Pour 10 ml of the first solution into dish one.
8. Place 10 ml of the second solution into dish two.
9. Insert 10 ml of the third solution into the third dish.
10. Pour 10 ml of the third solution into the third dish.
11. Pour 10 ml of plain distilled water into the dish number five.
12. Place ten beads in each solution. Repeat step twelve until there are ten beads in each dish.
13. Then take the eyedropper and suck up one daphnia at a time placing them into one ring at a time until finished.
14. Check the daphnia every ten minutes with a microscope and see how many are still alive. (Their heart will stop beating if they die.)
15. Record the times as follows: Time 0=starting time
Time 10=ten minutes past
Time 20=twenty minute past
Time 30=thirty minutes past
Time 40=forty minutes past
Time 50=fifty minutes past
Time 60=sixty minutes past
If some of the daphnia do not die, douse them in a heavy concentration of chlorine and then flush them.
* First Solution is 1% potent
* Second solution is 0.1% potent
*Third solution is 0.01% potent
*Fourth solution is 0.001% potent
RESULTS
The original purpose of this experiment was to find out whether different concentrations of chlorine affect the survival rate of daphnia.
The results of the experiment were that chlorine reduced the survival rate of daphnia considerably. It reduced the number of living daphnia usually within five minutes.
CONCLUSION
My hypothesis was that as chlorine concentrations increase, the percent of daphnia survival would decrease.
The results indicate that this hypothesis should be accepted.
Because of the results of this experiment, I wonder if similar results would be seen with other microorganisms.
If I were to conduct this project again I would use other pollutants instead of chlorine. In my experiment I would do more than one trial with more daphnia per trial.
| RESEARCH
REPORT
INTRODUCTION The food chain is the one of the most important components of human survival. The food chain is very important because one species depends on another. Unfortunately, If one type of organism were wiped out, many others would be affected. For instance, daphnia are a microscopic animal upon which salmon and other fish prey. Pollution is capable of damaging animals in the food chain. Daphnia Daphnia are crustaceans. A crustacean is an invertebrate animal that has many legs and a hard external shell. There are over 42,000 types of crustaceans. Daphnia are one of a few species of microorganisms with internal organs that can be seen easily by humans. The different species include the daphnia pulex and the daphnia magna. The daphnia pulex is a preferred type for culturing daphnia by researchers. Some of the other types of daphnia such as the Cyclops are a known predator to other smaller daphnia. If they are housed together they will dominate and eventually kill all other daphnia. Some of the daphnia, such as the magna, can be caught, bred, and matured within a month or two. Daphnia Facts Some of the daphnia's body parts are the heart (which is visible by the human eye), the egg pouch (on females), the eye, the tail, the stomach, two oar like fins, and also a set of gills. The sizes of daphnia can vary depending on the following: age, type, and the surroundings. If a daphnia pulex lives to maturity, it will get about a millimeter long. The diet of daphnia is a mixture of green algae, animal manure, or sometimes yeast. Daphnia's habitat can vary depending on where a reliable food source is. If there is a very good food source such as a stream with green algae, daphnia will usually be found there. Some of the predators of the daphnia include the Cyclops and the older daphnia. The reproduction of a daphnia is normally without fertilization, but sometimes when there is a loss of food, females will start to have many male babies, and then reproducing via fertilization occurs. Pollution Pollution is extremely dangerous because it affects every living thing. It can be deadly to humans and can certainly kill animals. Pollution helps to cause death by helping to destroy the food chain. For example, people on the beach often litter with plastic containers. By doing so, some of the birds come down to investigate and catch their necks in the holders. This causes strangulation and death to the bird. There are many ways to stop pollution and society needs to start using them. The causes for pollution are simple, people. If society started to use some of the common solutions, such as not littering or not selling spray cans that have the pressurized nozzle, the world would be a safer place to live. Pollution Facts There are many different types of pollution. One type is air pollution. Air pollution is caused by great amounts of smoke produced mainly by factories. Another type of pollution is water pollution. Spilling dangerous liquids and solids make the water toxic; thus causing water pollution. The biggest cause for water pollution is large barges carrying oil that hit a rock or end up in a storm and tip over. One of the ways to stop the pollution is by not manufacturing harmful products. Another way is to use enormous care when using these products. One pollution cycle is that when large factories release harmful pollutants into the environment, the water close by absorbs them. After the water absorbs them they eventually evaporate. The evaporated water then builds up in the clouds. When the cloud can't hold any more moisture it release all of the pollutants in something called acid rain. This damages the plants and can kill animals near by. SUMMARY Pollution is extremely harmful and needs to be stopped. If pollution continues eventually the food chain will be interrupted and lots of species will be wiped out. |
| Bibliography
"Daphnia." [Online] Available http://homepage.tinet.ie/~axolot/daphnia/ December 5,2000 "Daphnia Source." [Online] Available http://www.thekrib.com/Food/daphnia.html# 2 December 6,2000 Orlan, Barbara. Animal Care from Protozoa to Small Animals. Addison-Wesley Publishing, 1977. pp. 94-100 "Daphnia," World Book Encyclopedia 1998 Fetzer, Scott. "Planet Earth/Water," World Book's Young Scientist 1997 "Plant Life/Animal Life," The New Book of Popular
Science 1998
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I would like to thank the following people for their help with my science project:
Mr. Sweeney, Director of King County Environmental Labs in Seattle, and his staff, for growing and harvesting the daphnia pulex used in my project.
I would like to thank my dad for helping me with grammatical errors and other errors.
I would like to thank my mom for lending me supplies such as gloves and for supporting me all the way.
Next, I would like to thank my brother and sister for running minor trips to get a towel or something that I needed.
I would like to thank Mr. Newkirk for staying after school and letting me work on his computers.
Last, I would like to thank Mrs. Pasckvale for giving me tips on cutting my title and allowing me to stay after school.
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