Effect of Different Chemicals on Daphnia Heartbeats - Essay Example

Therefore, Daphnia and humans experience similar effects when exposed to specific toxic or chemical components (Grant, 2000). Daphnia Magna is generally used by scientists because the species is fairly easy to care for and provides accurate investigation results for water quality and toxicity. Thus the assessment of the effect of different chemicals on Daphnia Magna will give indications on the impacts of these chemicals on the human body. The objective of this report is to determine and distinguish the effect of toxicity on the heartbeat by testing the effect on Daphnia Magna.

Hypothesis
The interaction of foreign chemical components with the physiology of Daphnia Magna affects its heartbeats

Nonhypothesis

The interaction of foreign chemical components with the physiology of Daphnia Magna does not affect its heartbeats

Method:-
As described in the practical handbook as well as time course events.

Results
Heartbeats of Daphnia Magna after adding 3 chemicals and their combinations were recorded at different time intervals. The results have been tabulated in the table below

Heartbeats min-1

Control

A

B

C

A+B

B+C

A+C

Time

2 minutes

94

125

75

93

248

211

131

4 minutes

96

135

68

98

369

22

128

6 minutes

95

134

75

95

354

213

134

8 minutes

90

129

68

94

328

198

129

10 minutes

86

136

68

87

311

168

138

12 minutes

92

126

91

85

321

179

121

14 minutes

94

129

73

92

341

189

128

16 minutes

96

130

72

94

-

196

124

18 minutes

95

142

74

95

-

201

131

20 minutes

98

136

75

97

-

204

134

The following graph compares the changes in heart rates on the addition of 3 chemicals and their combinations.

Graph 1: Changes In Heart Rates On Addition of 3 Chemicals And Its Combinations.

Additivity
Graph 2: Comparison of the effect of A, B and the combination of A & B

Graph 3: Comparison of the effect of C, B and the combination of C & B
The graphs above compare the effect of chemicals in relation to the effect of their combination.

Antagonism
Graph 3: Comparison of the effect of C, B and the combination of C & B

Discussion:-

Graph 1:  Heart rate count per 15 seconds
Graph 1 indicates the effect on the heartbeat rate of Daphnia when exposed to chemicals A, B, and C and different combinations of A B, and C. The graph results show all the chemicals and their combinations. In comparison with the control, the combination of A and B had a relatively higher impact on the heart rates.  Chemical B individually reduced the heart rates of Daphnia. The combination of A and B and also the combination of B and C exhibited additivity. In both the combinations, the interaction of these chemicals was equivalent to the added impact of both the chemicals.

In the case of the combination of A and C, A interacted with C to reduce the effect of C. This is a case of antagonism. This combination is of clinical relevance as one chemical reduces the impact of the other.

Conclusion
From the observations, it is evident that all the chemicals and their combinations cause interactions with heart functioning and affects heart rates at varying levels. All the combinations including the individual addition of chemicals affected the heart rate of Daphnia. However, some of the effects were very less compared to others. Antagonistic interaction was observed between the chemicals A and C. Additivity was observed between the chemicals A and B and also between B and C. Thus the hypothesis of the report is supported by the findings of the study. However, there could be variations in results as when Daphnia was exposed to chemicals A and C it could have had a higher heartbeat rate. Moreover, as Daphnia can move on the slide and affect the microscope views, the results obtained from this experiment could have some errors which might produce variation in the figures. Also, there may be some errors when counting the number of heartbeats, or due to lack of experience and poor practical skills