Tell which of the following is a valid hypothesis (a, b, or both). For each, explain why it is or is not a valid hypothesis.
a) Does cigarette smoking cause cancer?
b) Cigarette smoking causes cancer.
Suppose that you conducted the following experiment. Three people drank 0.5 l of water and then climbed the stairs 3 times in a row. Their recovery time was then measured. Three other people each drank 0.5 l of Gatorade and then climbed the stairs 3 times in a row. Their recovery rate was also measured. The recovery times are below.
Group | Recovery Time (Seconds) |
water | 40, 45, 35 |
Gatorade | 50, 30, 40 |
State the hypothesis that is being tested by this experiment.
In what part of the lab report (or any scientific publication) would the following statements be found?
“The mean recovery time for group 1 was 40 seconds. The mean recovery time for group 2 was also 40 seconds.”
In what part of the lab report (or any scientific publication) would the following statements be found?
Three people drank 0.5 l of water and then climbed the stairs 3 times in a row. Their recovery time was then measured.
What would you put in the “Results” section of a scientific publication or lab report?
While hiking, Eric noticed that some beetles that were common in the forest were not found in the open fields. He was able to identify the beetles and used the Internet to find more information about them. He learned that they are scavengers; they eat dead and decomposing plant and animal material. Eric would like to know why the beetles are found in the forest but not the field since their food is found in both locations. He thinks that perhaps the microclimate in the field may be too harsh.
Construct a hypothesis that might explain Eric’s observation and describe an experiment that could be done to test the hypothesis.
Hypothesis:
Experiment:
Suppose that a researcher has discovered a chemical that she thinks might cause cattle to grow faster. List three questions that she could study using scientific method.
For one of the questions above, state a hypothesis and describe how you would test the hypothesis.
The next step depends on the outcome of your experiment. List what you would do for each of the possible outcomes
Suppose that a scientist discovered that cattle raised in pastures that had been fertilized with a certain fertilizer grow faster than normal. Give a hypothetical example of how she might have used scientific method to investigate this. You can answer this question by listing the steps of the scientific method that she used and tell what she did (or learned) in each step.
Sara wants to know if there was a relationship between cigarette smoking and recovery time (heart rate). State a hypothesis that she could test to determine if there is a relationship.
Sean wants to know if there was a relationship between consumption of candy bars and the amount of time it takes the hearat to recover after exercise. His hypothesis is that recovery time is greater in people that consume a candy bar immediately before exercising than in people that do not consume a candy bar. Design an experiment that would test his hypothesis. The experiment is to be done on a total of 10 people.