Review the following lab scenarios and answer the questions in a Word document.
1. A student wanted to study the effect of nitrogen fertilizer on plant growth, so she took two similar plants and set them on a windowsill for a two-week observation period. She watered each plant the same amount, but she gave one a small dose of fertilizer with each watering. She collected data by counting the total number of new leaves on each plant and measured the height of each plant in centimeters.
Which of the following is a significant flaw in this experimental set-up? Explain your answer.
a. There is no variable factor.
b. There is no control.
c. There is no repetition.
d. Measurable results cannot be expected.
e. It will require too many days of data collection.
2. A filter paper was placed in a choice chamber. One side of the filter paper was dry and the other side was wet. Students placed five pill bugs on the dry side of a choice chamber and five pill bugs on the wet side. The students collected data as to the number of pill bugs on each side every 30 seconds for 10 minutes. After 6 minutes, eight or nine pill bugs were continually on the wet side of the chamber, and several were under the filter paper. Which of the following is NOT a reasonable conclusion from these results?
a. It takes the pill bugs several minutes to explore their surroundings and select a preferred habitat.
b. Pill bugs prefer a moist environment.
c. Pill bugs prefer a dark environment.
d. Pill bugs may find chemicals in dry filter paper irritating.
e. Pill bugs demonstrate no significant habitat preference.
3. If a student wanted to determine whether pill bugs prefer a moist or a dry environment, which of the following scenarios would be the best way to analyze data from the experiment? Explain your answer.
a. Total the number of pill bugs on the dry side throughout the entire experiment and compare this with the number on the wet side throughout the experiment.
b. After waiting 5 minutes for the pill bugs to acclimate, count the number of pill bugs on the dry side every 30 seconds for 5 minutes. Total and average the results, and compare this with the number of pill bugs on the wet side during this same time interval.
c. Compare the number of pill bugs on the dry side at the end of 10 minutes with the number of pill bugs on the wet side at the end of 10 minutes.
d. Divide the number of pill bugs on the dry side throughout the experiment by the number on the wet side throughout the experiment.
4. Which of the following hypotheses is stated best? Explain why you selected your answer.
a. If pill bugs are allowed free movement, then more will be found in a moist environment than in a dry environment.
b. If pill bugs like a moist environment, then they will move to the wet side of a choice chamber.
c. If an experiment with pill bugs is run for 10 minutes, then more pill bugs will be found in the most favorable environment.
d. Pill bugs are found in a moist habitat, so I predict that more will be found where it is wet.