Choose one of the the problems listed on the hypothesis testing worksheet. Do not use one that has already been addressed here. In your own words, state what your hypothesis is, how you would test it and what controls you would use. Write your answer in the ” leave a comment ” section of this blog. I have to approve all submissions, so it may not appear right away. This assignment is due 6/15/2015 at 5PM.
7 points
Scenario:
4. Reversatol, a compound found in wine, has been suggested to lengthen life spans. How might you test whether this compound makes mice live longer? What controls would you use?
Hypothesis:
Regular intake of red wine, which contains the compound reversatol, can lengthen a persons lifespan.
Experiment:
A captive population of mice are fed an identical, simple but nutritious diet. Half of the mice are given a small serving of wine each day with their meals. Lifespans of all of the captive mice are recorded and compared.
Control:
The half of the mouse population that was not given wine with their meal serves as the control for this experiment.
1. Hypothesis: Aspirin lowers the rate of cancer.
Experiment: I would have a group of people take Aspirin on a regular basis for a certain amount of time and I wouldn’t have another group of people take any Aspirin at all during the same time frame. I would then determine whether the Aspirin group (the experimental group) developed cancers, such as breast or colon cancer, less frequently compared to the non-Aspirin group (the control group).
Control: Take no Aspirin for a certain period of time.
Experimental: Take Aspirin regularly for that same time period.
Hypothesis: By taking Aspirin on regular basis, the chance of an individual being diagnosed with cancer in their lifetime is lower than the chance of an individulal who doesn’t take Aspirin on a regular basis.
Experiment: I would start off by selecting a large population of baby mice that I could split into two groups randomly. Group 1 would not be given any Aspirin (control) and Group 2 would be given a dosage of Aspirin twice a day (experimental) until the experiment is completed. After the mice have been divided into two groups and Group 2 has received their treatment, I would give all mice a treatment of enough radiation that is known to cause cancer. I would then determine through tests how many of the mice from each group were diagnosed with cancer. After many trials, I could then report my findings and prove my hypothesis if everything worked out as expected.
Background: Previous experiments have demonstrated that mice will die when put into a glass container without a green plant present to produce oxygen.
Hypothesis: Light is required in order for green plants to produce oxygen. Therefore, if no light is present and the hypothesis is accurate, mice stored in a glass container with a green plant devoid of light will die.
Experiment: Use a small sample size of mice. Put a single mouse in a glass container with a green plant and store it in a room exposed to sunlight. Put another mouse in a glass container with a green plant and store each container in a dark room, completely void of light. Collect data on whether the mice live or die. The independent variable is the presence of sunlight, and the dependent variable in whether the mice live or die.
4. Hypothesis: Resveratrol is thought to increase life span, So if you gave mice resveratrol their life span would be longer than mice without.
Experiment: I would start with a nice group of mice that are the same age. I would test multiple mice for each group in order to ensure a more accurate conclusion. I would then give a group of the mice in separate enclosures a specific dosage of resveratrol per day, while I would i put another group of mice in separate enclosures no resveratrol. All the mice in the experiment would have the same type of enclosure and climate and would be fed all the same food and in the same proportions. Then I would watch the mice everyday giving the one group their dose of resveratrol while the other group received none, and over the course of time the mice would begin to die and I would record whether it was the a control group mouse which was given no resveratrol or if it was one of the experimental group mice dying and what time they died. I would then continue this until all the mice passed away and see if overall the resveratrol did allow the mice to live longer, or weather it did not. (You could also include more groups of different dosages of resveratrol to see if a larger or smaller dose would change the life span).
Background: An Ingredient in Sauerkraut has been suggested to be able to fight bird flu.
Hypothesis: When given Sauerkraut, organisms that have contracted bird flu are more successful at fighting the virus.
Experiment: Take two organisms that have contracted the bird flu at the same time have one eat Sauerkraut regularly and have the other maintain a Sauerkraut free diet and monitor the progression and recovery rate of the illness. The independent variable is the Sauerkraut and the dependent variable is how fast the organism recovers.
Read this completely wrong, so the hypothesis would be that since Sauerkraut was found to help in the bird flu it would also be successful in helping fight the swine flu.
Experiment: the experiment would be roughly the same, take two organisms that have contracted the swine flu at roughly the same time and have one include sauerkraut in its diet and the other one have a completely free sauerkraut diet and monitor the recovery rate of each organism. the dependent variable would be how fast the organisms recover and the independent variable would be the sauerkraut. It would be a good idea to compare these result to the results found in the organisms with bird flu.
“Some people believe that too much exposure to cell phones causes brain cancer. How might you test this whether this is true mice? What controls do you use?”
HYPOTHESIS: Prolonged exposure to radiofrequency emissions from cell phones causes brain cancer in mice.
I would design feeder dishes that house cell phone antennas under the bowl of food. This would ensure that the mice be consistently exposed (and at short range). I would connect the transmitters to an external circuit that runs them at the maximal power allowed by the FCC for use in cell phones. I would create bowls with transmitters of several frequencies (800 MHz to 2500 MHz), in case only certain frequencies cause brain cancer. 800 MHz, 1700 MHz, and 2500 MHz should be representative, so I would have three experimental groups and one control group.
The feeder dishes would be placed in cages, and the cages in identical (but unique) rooms in the same building, for consistency. Each room would have lead-lined walls in order to isolate each group of mice from their neighbors’ transmitter. Each cage would house several mice.
The control group would be housed in an identical cage in another (identical) lead-lined room. Their feeder would be of the same design, but just would not be powered on. All groups would receive the same ration of the same food and would have the same exercise equipment. Each room would have air quality control to ensure that the mice are not exposed to airborne carcinogens. Caretakers would be instructed to leave their cell phones outside of the lead-lined rooms (to avoid inconsistent exposure). Ideally, all mice would be from the same litter (or at least the same supplier).
Periodically, all groups would be inspected for signs of cancer, and toward the end of their life-expectancy, they would be comprehensively (and irreversibly) examined again.
Hypothesis: A compound called calestrol when given to mice that are given too much food to eat will cause the mice to lose weight.
Experiment 1: Over a span of multiple days take 10 mice and give them all too much to eat, but give each mouse the same amount to eat. 5 of the mice you will give the calestol to while the other 5 will be the control. Over these few days examine if the calestol causes the 5 mice taking it to eat less or not finish the amount they have been given and can usually eat, as well as this, examine the wait loss/gain of all 10 mice. If the mice are not finishing the food and losing weight you can determine the drug decreases the amount eats. If the mice are eating the same and still losing weight we can determine the weight is being lost by some other mechanism
Background: An ingredient in Sauerkraut has been suggested to be able to help fight the bird flu.
Hypothesis: If two groups of mice have swine flu, and you give sauerkraut to one of the groups and none to the other, more mice in the group who eats sauerkraut will be cured of bird flu than the group without.
Experiment: Take two groups of mice and isolate them from each other. Give both groups the bird flu. Give group 1 sauerkraut to eat with their food, and give group 2 only mice food. Record over the next few weeks the behavior and ailments of both groups of mice, including recovery rate.
The independent variable would be time, and dependent variable would be the sauerkraut and its magical ingredient. The control group would be group 2.
Hypothesis: Celastrol can decrease weight in mice that are fed too much food.
Experiment: I would obtain two groups of randomly picked adult mice and feed both groups the exact same amount of food to eat. Their starting body weights would be recorded before the experiment began. One group would be given Celastrol daily (experimental group) and the other group would not be given any Celastrol (control group). The body weights of the mice would be recorded daily and compared to the control group.
2. Purpose: To see if exposure to cell phones causes brain cancer.
Hypothesis: If two groups of mice are kept in separate places, and one group is exposed to a working cell phone constantly for a period of time, and the other is not, the group exposed to the cell phone will develop brain cancer.
Experiment: Take two groups of mice. Keep each group separate from one another, and let each group eat the same food; the only difference being that one group of mice is constantly exposed to a working cell phone, while the other is not. Over a period of time record the two groups, including their behavior and ailments, to see if brain cancer is developed. Compare and contrast both groups. The independent variable would be time, the dependent variable would be the cell phone, and the control would be the group of mice not exposed to the phone.
11. Hypothesis: Schizophrenia is related to an infectious agent called Toxoplasmosis.
For example some drugs that help control schizophrenia also affect the growth of toxoplasmosis. You decide to study some of these drugs further using rats. Rats that are infected with toxoplasmosis are less afraid of cats (which commonly carry the parasite). How might you determine whether these drugs alter the behavior of the rats? What controls would you need?
I would have the control group be ordinary rats living in the same environment with the same portions of food and water, and basically everything that could affect their way of living be the same. I will then have an experimental group of rats living in the same types of environments as the control group, the only difference being that they are infected with toxoplasmosis. I then will test the behaviors of each rat in the presence of the same cat to see if the behavior varies between the control group rats and the experimental rats. I would test this several times in hopes that for the most part I’ll get consistent patterns.
5. Scurvy bacteria?
At one time it was thought that scurvy might actually be a bacterial disease and that the poor diet simply made the sailors more susceptible to the disease.
Suppose you had a guinea pig with scurvy and found a new species of bacteria had infected it. How might you show that the scurvy was caused by the bacteria? What controls might you use?
Hypothesis: Scurvy is caused by bacteria.
Experiment: Give guinea pigs a regular diet. One group is not exposed or given the new species of bacteria (control) and one group is exposed to/given new species of bacteria (the experimental). Then establish whether the control guinea pigs get scurvy (or symptoms of scurvy) and whether the experimental guinea pigs get scurvy (or symptoms of scurvy).
Then you could do another experiment.
Here, the Hypothesis would be: poor diet makes guinea pigs more susceptible to scurvy.
Experiment: Have two groups of guinea pigs; one group that is fed a normal diet and one that is fed a poor diet. Then expose both groups to/give them the new species of bacteria. Then compare the results. You could establish things like the rate it was developed and find out if poor diet does or doesn’t make the guinea pigs more susceptible to scurvy.
The control: the new bacteria given to both groups. The experimental: the two groups of guinea pigs with different diets.
6. Hypothesis: Dogs can smell a person’s urine and detect whether or not they have cancer.
Experiment: Have a wide variety of dogs of different breeds and backgrounds smell the urine of a person with cancer and the urine of someone without cancer. Record how the dogs respond to the cancer free persons urine and compare and contrast it to how the dogs react to the cancer ridden person.
The control: The control would be the dogs reactions to the cancer free urine.
Cells in your blood can find and consume invading bacteria. Some specific compounds released by the bacteria have been suggested to attract the blood cells. How might you show that these compounds can attract the cells? What controls might you use?
Hypothesis: The invading bacteria release a compound that attracts the cells in your blood.
Experiment: Test 2 groups of rats each with the same food and water source. Inject the control group of rats with the bacteria. Inject the experimental group with a bacteria already found in their blood. Draw out a small amount of blood from each rat in each group. Compare the samples against each other.
Scenario 8 – Stem cells are cells that can either divide or turn into a specific type of cell. These cells may prove to be very useful in repairing damaged or diseased tissue.
Recently some experiments showed that it’s possible to turn skin cells into cells that are like stem cells.
How might you show that these are “real” stem cells and what are your controls?
Control group would be composed of real stem cells.
Experimental group would be composed of cells developed from skin cells that are similar to stem cells.
I propose manipulating each group carefully in an attempt to show that both test groups can divide and also turn into a non-skin cell. If that fails, further testing could be done on the experimental group to see if there are limitations on what those cells are capable of transforming into.
3.Hypothesis:The human ear can hear.
Experiment:I will have a group of rats with the human ear that I will stop their normal ears from hearing. Record how these rats respond to sound without their normal ears. I will compare and contrast the control and experimental groups to see what the human eared rats have that the normal rats do not.
Control group:I would have normal rats with their hearing stopped also. Just in case if the rats in the experimental group are reacting to vibrations rather than sound.
Example 10:
Hypothesis: Plants have tendency to grow towards the direction that they would receive the most optimal wavelength to preform photosynthesis (450 nm to 660 nm)
Experiment: Take two group of the same plant, same size, amount of dirt, amount of nitrogen, relatively same amount of leaves, and the same amount of water per day. The testing group will have the leaves facing away from where the wavelength is most optimal, while the control group will have the leaves facing where the wavelength is most optimal. If in deed the hypothesis is valid, the test group will turn their leaves towards the direction where the wavelength is most optimal. The direction where the photosynthesis is not optimal will be lower than 450 nm, if the direction that the plants grow is affected by the wavelength and how it relates to photosynthesis, the test group should turn to the higher wavelength side.