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9. (a) (i) Explain the importance of double-blind testing in scientific experimentation - Leaving Cert Biology - Question 9 - 2013
Question 9
9. (a) (i) Explain the importance of double-blind testing in scientific experimentation. (ii) How does a hypothesis differ from a theory? (b) Answer the following... show full transcript
Worked Solution & Example Answer:9. (a) (i) Explain the importance of double-blind testing in scientific experimentation - Leaving Cert Biology - Question 9 - 2013
Step 1
Explain the importance of double-blind testing in scientific experimentation.
Answer
Double-blind testing is a critical methodology in scientific experimentation aimed at eliminating bias. This approach ensures that neither the participants nor the researchers know who is receiving a particular treatment, thus preventing their expectations from influencing the results. By doing so, it maintains the integrity of the data and allows for a more objective evaluation of the treatment effects.
Step 2
How does a hypothesis differ from a theory?
Answer
A hypothesis is a preliminary statement or prediction that can be tested through experimentation. It is often narrow and specific. In contrast, a theory is a well-substantiated explanation that encompasses a broader scope of phenomena, supported by multiple lines of evidence and experimentation. Theories can evolve from multiple hypotheses that have been repeatedly tested and validated, providing a comprehensive framework within a scientific discipline.
Step 3
When investigating the effect of either carbon dioxide concentration or light intensity on the rate of photosynthesis: How did you vary your chosen factor?
Answer
In my investigation on carbon dioxide concentration, I varied the concentration of sodium bicarbonate (NaHCO₃) in the solution used for photosynthesis experiments. Alternatively, if investigating light intensity, I varied the distance of the lamp from the plant or adjusted the wattage of the lamp used.
Step 4
Using suitably labelled axes, draw a graph of the results that you obtained.
Answer
To present the data graphically, plot a graph with the rate of photosynthesis on the y-axis and the varying factor (either carbon dioxide concentration or light intensity) on the x-axis. Ensure both axes are clearly labelled, and the graph shows a trend indicating the relationship between the chosen variable and the rate of photosynthesis. Typically, one would expect to see an increase in photosynthesis rate with increased carbon dioxide concentration or light intensity, followed by a plateau as other factors become limiting.