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Introduction

BIOLOGY EXTENDED ESSAY BIOLOGY EXTENDED ESSAY What effect do the different concentrations of DDT and an AZO dye have on the opercular movement of Cirrhinus cirrhosus? Biology Supervisor: Shobit Saxena Word Count: 4100 CONTENTS Page No: * Research Question.............................................................. 2 * Abstract............................................................................. 4 * Introduction........................................................................ 5 * The Operculum and the breathing process of a fish * An Introduction to Cirrhinus Cirrhosus * About DDT * The textile industry * What Azo-Dyes are * Hypothesis......................................................................... 10 * Selecting Variables.............................................................. 10 * Apparatus Required............................................................. 14 * Procedure.......................................................................... 15 * Investigation I..................................................................... 17 * Investigation II..................................................................... 22 * Investigation III.................................................................... 27 * T-Test............................................................................... 31 * Conclusion and Evaluation..................................................... 32 * Extension of the experiment................................................... 37 * Terminology....................................................................... 39 * Bibliography....................................................................... 41 ABSTRACT I was inquisitive about the aquatic flora and fauna and their mass destruction due to the increase in chemical pollutants coming from industries, agricultural farms and houses. Therefore I thought and pondered about the reasons behind this destruction and the question which I thought would be worthy of investigation is: "What effect do the different concentrations of DDT and an AZO dye have on the opercular movement of Cirrhinus cirrhosus?" For this research, I investigated the effects of DDT and an Azo-Dye on the opercular movement of Mrigal (Cirrhinus cirrhosus) a fresh water fish. This was attained by performing primary research, which was achieved by setting up 3 similar experiments, first using different concentrations of DDT, second using different concentration of the Azo-Dye and third using a mixture of these two toxins. All the experiments were carried out to find out the difference in opercular movement in fish, as it would help answer my question. For the first and second experiment, I obtained 25 data for each concentration, and 125 data for all the concentrations of DDT including the controlled experiment. The same was repeated in the third, however data collected was 25 for the mixture and 50 including the controlled experiment. ...read more.

Middle

145 150 147.2 148.22 3.56 3.70 D 149 152 147 142 150 148 3.81 E 145 150 147 155 150 149.4 3.78 1 A 120 138 127 131 124 128 6.89 B 119 128 130 134 120 126.2 6.50 C 121 130 127 133 125 127.2 127.04 4.60 5.51 D 130 133 130 125 120 127.6 5.13 E 131 120 125 125 130 126.2 4.44 2 A 66 48 52 48 58 54.4 7.67 B 54 56 60 59 50 55.8 4.02 C 50 60 48 55 48 52.2 54.32 5.22 D 60 62 48 50 50 54 6.48 5.63 E 54 60 59 55 48 55.2 4.76 4 A 30 28 26 32 25 28.2 2.86 B 33 31 24 27 24 27.8 4.09 C 30 32 24 26 24 27.2 28.24 3.63 3.07 D 30 33 31 27 30 30.2 2.17 E 28 27 31 24 29 27.8 2.59 6 A 21 20 16 18 14 17.8 2.86 B 24 21 21 14 14 18.8 4.55 C 16 14 16 18 16 16 17.4 1.41 2.68 D 20 14 18 16 18 17.2 2.28 E 14 18 18 16 20 17.2 2.28 RESULT GRAPH: PERCENTAGE DIFFERENCE OF THE OPERCULAR RESPONSE SHOWN BY THE FISH OBSERVATION TABLE: Initial Opercular movement in the controlled beaker/min Doses of DDT/ppm Final Opercular movement in the different concentration of DDT/min DIFFERENCE/ppm PERCENTAGE DIFFERENCE/% 148.22 0 148.22 0 0.00 148.22 1 127.04 21.18 -14.29 148.22 2 54.32 93.9 -63.36 148.22 4 28.24 119.98 -80.95 148.22 6 17.4 130.82 -88.27 OBSERVATION GRAPH: INVESTIGATION II: TO STUDY THE OPECULAR RESPONSE OF FISH UNDER DIFFERENT DOSES OF AZO-DYE IN LABORATORY CONDITIONS. After carrying out the procedure suggested for Investigation II. We arrive at the following results: RESULT TABLE: EFFECT OF THE DIFFERENT CONCENTRATIONS OF THE AZO DYE ON THE OPERCULAR MOVEMENT OF CIRRHINUS CIRRHOSUS Doses of DYE/ppm Beaker: Opercular movement/min Mean opercular movement/min Average SD Mean of SD (fishes) ...read more.

Conclusion

* The effects of such toxins on the aspects of the ecosystem like Bio-accumulation and Bio-magnification : An abstract from the IB Biology text has shown a study of this principle with an example of DDT: DDT sprayed on water to eliminate mosquito larvae will be taken up by algae. As each level of the food chain is eaten, DDT levels increase because it cannot be excreted with urine due to its poor solubility. Hence it accumulates within the organisms and then is magnified as many organisms from one trophic level are eaten by a few from the next trophic level. * The same experiment or different experiments can be performed on the same lines as this extended essay. Different fresh water fish may be tested upon or different aquatic animals found at contaminated areas. The experiment does not have to stop at aquatic life. Those animals which drink water from nearby areas may also face the effect of these toxins. This is why the response of such toxins can be studied on regular animals as well. TERMINOLOGY * Half-life: The period of time it takes for a substance undergoing decay to decrease by half.10 * Runoff: The washing away of nutrients from the soil due to the flow of water. * Volatilization: The process whereby a dissolved sample is vaporized. In atomic spectroscopy this is usually a two step process.11 * Photolysis: A chemical reaction in which a chemical compound is broken down by photons.12 * Biodegradation: The chemical breakdown of materials by a physiological environment.13 * Biomagnification: The increase in concentration of a substance, which occurs in a food chain.14 * Bioaccumilation: The increase in concentration of a substance in certain tissues of organisms' bodies due to absorption from food and the environment15 * Mutagenic: A physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level.16 * Hydrophobic: The physical property of a molecule that is repelled from a mass of water. 17 * Basal cell carcinoma: the most common type of skin cancer. ...read more.

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