Photo AI
9. (a)(i) What is the purpose of a hypothesis in the scientific method? (ii) Explain what is meant by double-blind testing in scientific experimentation - Leaving Cert Biology - Question 9 - 2015
Question 9
9. (a)(i) What is the purpose of a hypothesis in the scientific method? (ii) Explain what is meant by double-blind testing in scientific experimentation. (b) A sc... show full transcript
Worked Solution & Example Answer:9. (a)(i) What is the purpose of a hypothesis in the scientific method? (ii) Explain what is meant by double-blind testing in scientific experimentation - Leaving Cert Biology - Question 9 - 2015
Step 1
What is the purpose of a hypothesis in the scientific method?
Answer
The purpose of a hypothesis in the scientific method is to form the basis of a prediction or to provide a starting point for an experiment. It serves as a potential explanation for observations, allowing scientists to test its validity through experimentation.
Step 2
Explain what is meant by double-blind testing in scientific experimentation.
Answer
Double-blind testing is a procedure in which neither the experimenter nor the test subjects know who is receiving a particular treatment. This method helps eliminate bias in the results, ensuring that any effects observed can be attributed to the treatment itself rather than expectations or behaviors influenced by knowledge of the treatment.
Step 3
Why do you think it was important that all the tadpoles came from the same mother?
Answer
It was important that all the tadpoles came from the same mother to ensure genetic similarity among the subjects. This reduces variability in their response to iodine and allows for a more accurate assessment of how concentration affects growth, as any differences observed can be more confidently attributed to the iodine concentration rather than genetic differences.
Step 4
Why is a control essential in scientific experiments?
Answer
A control is essential in scientific experiments because it provides a standard or baseline to compare with the experimental results. This allows the scientist to determine whether the treatment has a significant effect, helping to assure that any observed changes are due to the experimental variable rather than other factors.
Step 5
Suggest why he used 25 tadpoles in each group.
Answer
Using 25 tadpoles in each group allows for a larger sample size, which can help make the results statistically significant. This sample size also accommodates potential losses due to illness or death, ensuring there are enough subjects to draw reliable conclusions from the experiment.
Step 6
Suggest how this investigation would have been carried out.
Answer
The investigation would have been carried out by dividing the 100 tadpoles into four groups of 25. Each group would be exposed to different concentrations of iodine solution, while one group would serve as the control, receiving no iodine. The growth of the tadpoles would be measured over a specified period, recording the changes in size and health, to observe the effects of iodine concentration.
Step 7
Suggest two factors that the scientist would have kept constant during the investigation.
Answer
Two factors that the scientist would have kept constant during the investigation include the amount of food provided to each group of tadpoles and the volume of water used in each tank. Additionally, other environmental conditions, such as temperature and light exposure, would also be maintained to prevent external variables from influencing the results.