Texts: Questions 6-10 describe a scientific hypothesis and ask about the experimental design to accurately test the hypothesis. A substance has been identified from the fur of a tropical mammal that has some fungicidal properties (inhibits the growth of fungi) and is not toxic to mammals. The active ingredient, called mycoinhibin, in the substance could be useful in preventing the growth of fungi on wood products. Hypothesis: Mycoinhibin will not decrease the growth of fungi on wood products.
Question 6: Which of the following statement or statements most accurately describes the appropriate experimental design to test the hypothesis?
Group of answer choices:
1. The amount of mycoinhibin applied to the wood must be measured precisely.
2. In this controlled experiment, all samples must receive the same amount of mycoinhibin.
3. Different amounts of mycoinhibin should be applied, including one sample with none.
4. Both A & B
5. Both A & C
During the experiment, the temperature of the wood samples:
Group of answer choices:
1. Should be different for each sample to determine the effect of temperature on fungal growth.
2. Should be between 25 and 35 degrees Celsius because it will increase the growth rate of most fungi.
3. Must be controlled precisely and must be the same for all the wood samples.
4. The samples without mycoinhibin should be at a cooler temperature to slow fungal growth.
Some plants, such as cedars, produce chemicals that are "natural" fungicides. Therefore,
Group of answer choices:
1. You should use varieties of wood, including cedar.
2. You should use woods that do not produce their own fungicide.
3. The wood samples with natural fungicide should receive more fungal spores.
4. Both A & C
As part of the experimental design,
Group of answer choices:
1. Different fungal species should be applied to different samples to see which grows the best.
2. Different amounts of fungal spores should be applied to the control samples.
3. Fungal samples should have a variety of moisture content to determine the effects of moisture.
4. The same amount of fungal spores should be applied equally to all samples.
Which of the following could be a potential uncontrolled variable in this experiment that would make the experiment invalid?
Group of answer choices:
1. All wood samples are in the light during the day but not in the light during the night.
2. The wood might be warmer during the day than at night.
3. Different amounts of fungal growth appear on different samples.
4. Different species of fungal spores applied to the control group versus the experimental group.