Bio 180 Exam 1 Questions With 100%
Verified Answers
What is the difference between a theory and a hypothesis? -
correct answer ✅Only scale--theories deal with "big ideas" that
impact large parts of the physical or natural world; hypotheses are
more focused or narrower in scope.
What is the difference between a hypothesis and a prediction? -
correct answer ✅A hypothesis is an idea--a testable explanation; a
prediction is something that follows from a hypothesis and that you
can measure
example of prediction -
correct answer ✅If you boil nutrient broth and place it in an air-
tight flask, no cells will appear in the broth
What was important about the experimental design for Pasteur's
flask experiment? -
correct answer ✅He compared results from two experimental
setups which differed only in the type of flask in which the nutrient
broth was placed
How do biologists test their ideas about the natural world? -
correct answer ✅Scientists make predictions based on hypotheses
,Bio 180 Exam 1 Questions With 100%
Verified Answers
they have developed, and then design experiments or other types
of studies to test those predictions
Why is it important to perform multiple trials in an experiment --
meaning that you include many test individuals or samples? -
correct answer ✅To make it more likely that the results are not
due to a few unusual individuals or circumstances
The remaining questions refer to this situation: Researchers do an
experiment to test the hypothesis that Douglas fir trees put more
resources into reproduction when they are infected with a fungus
that causes a fatal disease. They establish study plots in a group of
50-year-old Douglas fir where the disease is not present. At
random, they inject half the trees with the disease-causing fungus.
Then they measure how many cones and seeds are produced by
infected versus uninfected trees.
What prediction follows from the hypothesis? -
correct answer ✅On average, the infected trees will produce more
seeds than uninfected trees
Which treatment would be considered the control? -
correct answer ✅The uninfected trees
,Bio 180 Exam 1 Questions With 100%
Verified Answers
Why is it important to do the experiment in the same group of
same-aged trees? -
correct answer ✅To eliminate the possibility that the results are
due to differences in age, soil, moisture, or other relevant variables
Why is it important that they assigned trees to the infected versus
uninfected groups at random? -
correct answer ✅If assignment were not done at random, the
result could be do to something other than the difference in
infection
If the hypothesis is wrong, and being infected with the fungus has
no impact at all on reproduction, what should they observe? -
correct answer ✅There will be no difference in the number of
seeds produced by infected versus uninfected seeds
A friend says that this experimental design would be better if the
researchers had injected the control group trees with a solution
that was identical to that used in the experimental group, but
without the fungus. Do you agree? -
correct answer ✅Yes. As is, it would be reasonable for a critic to
, Bio 180 Exam 1 Questions With 100%
Verified Answers
claim that seed production changed because of the injection itself,
not the presence of the fungus.
What does the p in "p-value" represent? -
correct answer ✅Probability (of getting the observed result, just
by chance)
Suppose we run a statistical test, and learn that p = 0.01. What
does this mean? -
correct answer ✅There is a 1 in 100 chance of observing a
difference between treatment groups this extreme if the null
hypothesis is correct.
If we want to plot the distribution of scores on Exam 1, we should
use a... -
correct answer ✅Histogram
If we want to plot the exam scores of 1st-year students versus 2nd-
year students, we would use a ... -
correct answer ✅Bar chart
Verified Answers
What is the difference between a theory and a hypothesis? -
correct answer ✅Only scale--theories deal with "big ideas" that
impact large parts of the physical or natural world; hypotheses are
more focused or narrower in scope.
What is the difference between a hypothesis and a prediction? -
correct answer ✅A hypothesis is an idea--a testable explanation; a
prediction is something that follows from a hypothesis and that you
can measure
example of prediction -
correct answer ✅If you boil nutrient broth and place it in an air-
tight flask, no cells will appear in the broth
What was important about the experimental design for Pasteur's
flask experiment? -
correct answer ✅He compared results from two experimental
setups which differed only in the type of flask in which the nutrient
broth was placed
How do biologists test their ideas about the natural world? -
correct answer ✅Scientists make predictions based on hypotheses
,Bio 180 Exam 1 Questions With 100%
Verified Answers
they have developed, and then design experiments or other types
of studies to test those predictions
Why is it important to perform multiple trials in an experiment --
meaning that you include many test individuals or samples? -
correct answer ✅To make it more likely that the results are not
due to a few unusual individuals or circumstances
The remaining questions refer to this situation: Researchers do an
experiment to test the hypothesis that Douglas fir trees put more
resources into reproduction when they are infected with a fungus
that causes a fatal disease. They establish study plots in a group of
50-year-old Douglas fir where the disease is not present. At
random, they inject half the trees with the disease-causing fungus.
Then they measure how many cones and seeds are produced by
infected versus uninfected trees.
What prediction follows from the hypothesis? -
correct answer ✅On average, the infected trees will produce more
seeds than uninfected trees
Which treatment would be considered the control? -
correct answer ✅The uninfected trees
,Bio 180 Exam 1 Questions With 100%
Verified Answers
Why is it important to do the experiment in the same group of
same-aged trees? -
correct answer ✅To eliminate the possibility that the results are
due to differences in age, soil, moisture, or other relevant variables
Why is it important that they assigned trees to the infected versus
uninfected groups at random? -
correct answer ✅If assignment were not done at random, the
result could be do to something other than the difference in
infection
If the hypothesis is wrong, and being infected with the fungus has
no impact at all on reproduction, what should they observe? -
correct answer ✅There will be no difference in the number of
seeds produced by infected versus uninfected seeds
A friend says that this experimental design would be better if the
researchers had injected the control group trees with a solution
that was identical to that used in the experimental group, but
without the fungus. Do you agree? -
correct answer ✅Yes. As is, it would be reasonable for a critic to
, Bio 180 Exam 1 Questions With 100%
Verified Answers
claim that seed production changed because of the injection itself,
not the presence of the fungus.
What does the p in "p-value" represent? -
correct answer ✅Probability (of getting the observed result, just
by chance)
Suppose we run a statistical test, and learn that p = 0.01. What
does this mean? -
correct answer ✅There is a 1 in 100 chance of observing a
difference between treatment groups this extreme if the null
hypothesis is correct.
If we want to plot the distribution of scores on Exam 1, we should
use a... -
correct answer ✅Histogram
If we want to plot the exam scores of 1st-year students versus 2nd-
year students, we would use a ... -
correct answer ✅Bar chart
