A2 fiffAnswers
Figure 1.5
Q1: Give a possible hypothesis that could be tested by weighing the
bats.
A1: Hypothesis: Bats with WNS weigh less than uninfected bats.
Q2: State the hypothesis being tested in the photo on the bottom
right.
A2: Hypothesis: Healthy bats injected with a fungicide will have
lower rates of infection by WNS than will bats that are sham
injected (no fungicide).
Q3: Explain in your own words why an experimental study is the
only way to show a cause-effect relationship.
A3: One possible explanation: If you find a relationship between
two variables in an observational study, you can’t know which one
causes the other, or even whether a third variable is causing both
to occur. In an experimental study, it is possible to manipulate
one variable and see whether that manipulation causes a second
variable to change.
Figure 1.6
Q1: Which is the control group in this experiment, and what are
the three treatment groups?
A1: Control group: Housed alone, with no exposure to WNS.
Treatment groups: Housed in air contact but not physical contact
with infected bats; housed in physical contact with infected bats;
with fungus applied to wings.
Q2: What is the hypothesis being tested in this experiment?
A2: Hypothesis: WNS is caused by contact with the fungus
Geomyces destructans.
Q3: In one or two sentences, state the conclusions you can draw
from the experiment. Was the hypothesis supported? Why or why
not?
A3: Bats that come into physical contact with Geomyces
destructans are highly likely to develop WNS, whereas those
exposed only through the air do not develop WNS. The hypothesis
was supported in part (physical versus air contact).
Figure 1.7
Q1: What is the control group in this experiment, and what are the
two treatment groups?
A1: Control group: Sham injection. Treatment groups: Injected
with Geomyces destructans from North America; injected with G.
destructans from Europe.
Q2: At day 40, approximately how many individuals were alive in
each treatment group? At day 80? At day 100?
A2: Day 40: 100% of all groups survived. Day 80: 100% of control
and North American G. destructans (Gd) groups survived; 14 of
18 in the European Gd group survived. Day 100: 100% of control
group survived; 13 of 18 in the North American Gd group survived;
only 2 of 18 in the European Gd group survived (although the
European Gd experiment was stopped at about day 90).
Q3: In one or two sentences, state the conclusions you can draw from
the experiment. Was the hypothesis supported? Why or why not?
A3: Conclusion: Geomyces destructans causes WNS and leads to
higher mortality. The hypothesis was supported. The study found
that WNS was, in fact, caused by the fungus.Figure 1.8
Q1: Give one fact about bats that you learned from this chapter.A1: One possible fact: Bats can develop fungal infections.Q2: What is another example of evidence for the germ theory of
disease? (Hint: Think about human diseases.)A2: One example would be strep throat, caused by Streptococcus
bacteria and cured by antibiotics.Q3: Explain in your own words the difference between a fact and a
hypothesis, and between a hypothesis and a theory.A3: Hypotheses are not as certain and are more complex than
facts; they are simpler and less well documented than theories.Figure 1.9
Q1: Give examples of other kinds of organs that mammals such as
bats have. (Hint: Think of the organs in your own body.)A1: Examples include kidney, liver, heart, lungs.Q2: Are bats in California part of the community of bats in upstate
New York, if they are of the same species? Why or why not?A2: No, they are not, because they do not interact with each other.Q3: Is the soil in a cave where bats live a part of the bats’
population, community, or ecosystem? Explain your reasoning.A3: Soil is part of the ecosystem; populations and communities
are composed only of living things, and soil is part of the physical
environment.CHAPTER 2
END-OF-CHAPTER ANSWERS
- b
- c
- d
- scientific literacy: 2, basic research: 5, applied research: 1,
secondary literature: 4, primary literature: 3 - credentials, bias, secondary literature
- (a) 1, (b) 6, (c) 3, (d) 2, (e) 4, (f ) 5
- a
- (a) primary, (b) neither, (c) neither, (d) secondary
- c
- (a) Pseudoscience. Dr. Oz has relevant credentials but, from
the success of his TV show, appears to have an agenda. In
addition, the idea of a “fat-burning” dietary aid does not align
with current scientific understanding.
(b) Pseudoscience. The idea of a scientific conspiracy is a red
flag, as is the rejection of scientific consensus. And though the