Reference no: EM133418291
1. The Strange Case of "BeriBeri"
In 1887 a strange nerve disease attacked the people in the Dutch East Indies. The disease was called Beriberi. Symptoms of the disease included weakness and loss of appetite; victims often died of heart failure. Scientists thought the disease might be caused by bacteria. They injected chickens with bacteria from the blood of patients with Beriberi. The injected chickens became sick. However, so did a group of chickens that were not injected with bacteria.
One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten whole-grain rice, but during the experiment, the chickens were fed polished rice. Dr. Eijkman researched this interesting case. He found that polished rice lacked thiamine, a vitamin necessary for good health.
A. State the problem or question.
B. What was the hypothesis?
C. How was the hypothesis tested?
D. Should the hypothesis be supported or rejected based on the experimental results?
E. What should be the new hypothesis?
2. Which Sunflower Seeds Are Best?
It's spring and you decide that you want a summer sunflower garden! You go to the local nursery and see that the sunflower seeds cost $1 per 8 oz. package. However, further down the aisle, you notice a 5 lb. bag of sunflower seeds for the purpose of bird feed for only $7.
Design an experiment to test whether there is a difference in the quality of seed from the two sources. Be sure to answer the following in your experimental design.
A. What is your research question/problem?
B. What is your hypothesis for the experiment?
C. Describe in detail the design of your control group.
D. Describe in detail the design of your experimental group.
E. What is the variable in your experiment?
F. How would you decide whether to accept or reject your hypothesis?
In addition to describing your experiment using words, help me visualize your experimental design by drawing diagrams and/or pictures of how you would set up the experiment.
3) How Do Robins Catch Worms?
One afternoon, you notice several robins hopping around in the ORU prayer gardens. You see that one robin hops a distance of one or two feet and pauses for a few seconds with his head cocked and then moves another couple of feet. Occasionally, the robin will stab at the ground. You notice that eight times out of ten, he successfully obtains a worm.
A. What is the research question?
B. Based on the observations you made in the prayer gardens, state a possible hypothesis that might explain how the robin detects the worm. Try to state it in the "if...then..." format.
C. Based on your hypothesis, how would you design an experiment to test how robins capture worms? In addition to describing your experiment using words, help me visualize your experimental design by drawing diagrams and/or pictures of how you would set up the experiment. Be sure to include in your experiment description the following: variable, control group, and experimental group.
D. How would you decide whether to reject or accept your hypothesis?
4. Errors in Experiments
Explain what is wrong with each of these experimental designs.
A. A farmer wanted to know if XYZ fertilizer would be good for growing vegetables in his garden. He fertilized all his 100 bean plants with XYZ but didn't put any fertilizer on his 100 pepper plants. His beans didn't do well at all, but he got a good crop of peppers. He concluded that XYZ fertilizer was no good.
· What was the research question?
· What was the variable?
· What was/were the error(s) in the farmer's experiment? (Choose one or more common errors from the following list.)
o Not enough subjects
o Subjects were not similar
o Conditions were not kept the same
o The experiment was not reproduced
B. Alice Larsen wanted to see if a new premium gasoline would give her more miles to the gallon. She filled her car with the new gas and went on a long trip. When she figured out her mileage, she discovered that she had gone 20 miles farther on this tank of gas than she had gone on a tank of regular gas when she was driving around town as usual. She decided to buy the premium gas from then on to get better gas mileage.
· What was the research question?
· What was the variable?
· What was/were the error(s) in Alice's experimental design? (Choose one or more common errors from the following list.)
o Not enough subjects
o Subjects were not similar
o Conditions were not kept the same
oThe experiment was not reproduced
A molding machine in a factory was not working very well. About a third of the time, the plastic squirt guns that it was making came out with a flaw on the handle. The repair mechanic adjusted the stamping pressure. Then she ran one gun through. It came out just fine, so she figured she had solved the problem.
· What was/were the error(s) in the conclusion of the repair mechanic? (Choose one or more common errors from the following list.)
o Not enough subjects
o Subjects were not similar
o Conditions were not kept the same
o The experiment was not reproduced
5. Caffeine may ease post-workout muscle pain
Read the news article below and answer the questions at the end.
"Caffeine May Ease Post-Workout Muscle Pain" https://www.reuters.com/article/idUSHAR76988020070117
By Amy Norton NEW YORK | Wed Jan 17, 2007 2:50pm EST
NEW YORK (Reuters Health) - That morning cup of coffee may be an antidote to post-exercise muscle soreness, if preliminary research is correct. In a small study of female college students, researchers found that a caffeine supplement seemed to lessen the familiar muscle pain that crops up the day after a particularly challenging workout. Known as delayed-onset muscle soreness, or DOMS, the pain is common in the day or two after a workout that was more intense than normal. Exercise that involves eccentric contraction of the muscles is particularly likely to cause delayed muscle pain. In eccentric contraction, the muscle produces a force while it's being lengthened. This happens when a person runs downhill, for example, or lowers a weight during a bicep curl. Exercisers and researchers alike have tried many ways to prevent DOMS -- including over-the-counter painkillers, stretching and massage -- but studies have found no cure-all for the problem. In the current study, published in the Journal of Pain, researchers at the University of Georgia in Athens looked at the effects of a caffeine supplement on delayed muscle pain in nine young women.
First, in a simulated workout, the researchers used electrical stimulation to produce eccentric contractions in the women's thigh muscles -- enough to cause moderate day-after soreness.
Next, they repeated the procedure over the next two days, but on each day, the women took either a caffeine pill or placebo pill one hour before the muscle workout. Neither the women nor the researchers knew which pill was given on which day.
Overall, the women reported significantly less muscle soreness during the workout when they took caffeine instead of the placebo. The supplement had about the amount of caffeine found in two cups of coffee.
A. What is the research question/problem?
B. What is the hypothesis for the experiment?
C. Describe the control group.
Describe the experimental group.
E. What is the variable in the experiment?
F. List three flaws in the experimental design.
G. Redesign this experiment. In addition to describing your experiment using words, help me visualize your experimental design by drawing diagrams and/or pictures of how you would set up the experiment. Be sure to include in your experiment description the following: variable, control group, and experimental group.