Question 1
Question 140 pts
Susie works for a lab company that develops many different pharmaceutical products. Her research division has stumbled across a new drug that they believe cures male pattern baldness. Before they can start selling the drug, they must demonstrate to the U.S. Food and Drug Administration that the drug is effective. The company puts Susie in charge of this research project.
Susie randomly selects two groups of men to participate in the study:
Group A and Group B.
Group A is administered the drug in pill form once a day for six months.
Group B is given a pill that contains only inert ingredients once a day for six months.
All of the men will have the number of hairs per square inch of scalp measured in the clinic once per week.
- What is the first step that Susie must complete when utilizing the scientific method?
- Identify the experimental group in Susie’s study (Group A or Group B).
- What is the dependent variable in Susie’s study?
- After Susie reports the results, what step in the scientific method will be next?
Question 2
Question 230 pts
Carl is conducting an experiment to determine if increased ultraviolet radiation from the decrease in the ozone layer is killing off frog tadpoles. After examining all of the data available in the library, Carl decides to go with a hypothesis that increased ultraviolet radiation from the sun is killing off the tadpoles.
Carl puts tadpoles into two groups. Group 1 involves 100 tadpoles in a five gallon container of water, which is covered by glass (knowing that the glass will filter out the ultraviolet radiation). Group 2 will be set up exactly like Group 1, except instead of being covered with glass, it is covered with an acrylic plexiglass, which will not filter out the ultraviolet radiation. Carl then places the groups outside for a period of one month, and observes the results.
Results
Group 1 Group 2
______________________________________________________________________________
Number of tadpoles at the 100 100
beginning
Number of tadpoles at the 96 96
end
______________________________________________________________________________
- What is the experimental (independent) variable?
- Which group is the control group (Group 1 or Group 2)?
- Do the results of this experiment support Carl’s hypothesis?
Question 3
Question 330 pts
Niko Tinbergen (1907 – 1988) was a Swedish Ethologist (animal behaviorist) famous for studying animals in their native habitats. One of his classic experiments involved a bird called the black-headed gull (Larus ridibundus). Black-headed gulls build nests of twigs on the ground and lay light brown eggs that are covered with dark brown spots. However, the inside of the egg is white in color. Tinbergen noticed that adult gulls pick up the eggshells shortly after a chick has hatched, and fly them to a location far from the nest, where they are left. Since this behavior required expending energy and time that could have been spent feeding and protecting the chicks, Tinbergen wanted to know why the birds did this.
Experiment:
Tinbergen and his co-workers collected gull eggs and painted 69 of them white and left 68 of them with their natural color. (Statistically, these numbers are close enough to be considered equal.) The researchers then scattered the eggs next to a gull breeding area and observed from a nearby blind. Predation rates were recorded for white versus natural colored eggs.
Results:
Original Number of Eggs Eggs Taken by Predators
______________________________________________________________________________
White Eggs 69 43
Natural Eggs 68 13
______________________________________________________________________________
- Which step of the scientific method is represented by the following statement?
The white interior of the shell is not camouflaged and attracts predators to the nest. Therefore, the gulls remove the shells to decrease predation.
- What is the difference in the control group and the experimental group in Tinbergen’s study?
- Do the results of Tinbergen’s study support the hypothesis?
