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Understanding labels and ads
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Testimonials are not valid in science.
This had two groups and a control.
Also this had a large sample size.
A magazine included advertisements for two different garlic
supplements to promote healthy hearts. The
advertisement for Very Good Garlic Extract presents
evidence that is more valid because —
A information was gathered in a controlled manner
B it lacks a guarantee
C it lacks personal testimonials to the product’s
effectiveness
D information was gathered in more than one country
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D
A
C
B
Which conclusion can reasonably be
made about Glycotac based on the
promotional brochure?
Glycotacwith
is notdiabetes
for everybody.
A All people
can safely use
the product.
Glycotacisisguaranteed
not for people with
kidney,blood
B Glycotac
to lower
heart
or infection
problems.
sugar in
people
without
health problems.
C Using the product may lower bloodsugar levels.
D Glycotac eliminates the need to
Glycotac in addition to exercise.
exercise to control high blood sugar.
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An advertisement claims that patients canHome
be cured of the common cold in 48 hours by
vitamin C tablets with secret mineral
supplements. In a scientific experiment to
test these claims, which data can be
considered irrelevant?
A The amount of vitamin C in each tablet
B The severity of the patients’ cold
symptoms
C The chemical formula for vitamin C
D The amount of time before symptoms
improve
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Recommended is 50 mg of B6
and 800 µg for Folate
There’s no B12 in this cereal.
Many doctors recommend 800 µg of folate, 400Home
µg of vitamin B12, and 50 mg of vitamin B6 per
day to improve cardiovascular health. Based on
this information and the nutrition label, the
cardiovascular health benefit of a 1-ounce serving
of this cereal is —
A doubtful because it provides insufficient folate
and vitamin B6 and lacks vitamin B12
B superb because it contains only 22 g of
carbohydrates and 75 mg of sodium
C excellent because it provides all needed
vitamins and is low in fat and cholesterol
D poor because it raises blood cholesterol levels
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with its high fat and cholesterol content
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Home
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An herbal company advertises that
its product will help people lose Home
1 a tablespoon of
weight if they take
the product with a glass of water at
bedtime each night. Weight
loss
is
2
guaranteed if a person does not eat
for at least 3 hours before bedtime,
3
4
gets moderate exercise, and drinks
8 glasses of water each day.
Why is the company’s claim difficult
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to verify?
F The company has yet to disclose the
identity of its special herb.
G Numerous uncontrolled variables are
involved in evaluating results.
H Fasting lessens the absorption rate
of the herb.
J The advertisement lacks data from
before and after the weight loss.
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Scientific Method
Recognizing well designed scientific investigations
Choosing “best statements” or conclusions.
Choosing “beginning question” or “hypothesis”
that led to the experiment given.
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Two science students discovered thatHome
the mass of a sample of acetone in an
open beaker decreased within a few
minutes.
One student hypothesized that the
acetone reacted with oxygen to form a
gaseous compound that escaped. The
other student believed that the acetone
evaporated into the air. What should
the students do to test these
hypotheses?
F Combine the hypotheses so they give Home
valid predictions of the acetone’s behavior
G Conduct a study of original papers
describing the experiments leading to
acetone’s discovery
H Perform an experiment that attempts to
identify the gas above the open beaker
J Ask a classmate’s opinion about the
chemical and physical properties of acetone
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An engineer has created a new engine for race
cars. It is necessary to know which fuel mixture
will allow the engine to run at its peak
performance. Which experimental design is best
for this investigation?
F Use one fuel mixture on the engine and
measure its performance
G Use one fuel mixture on many types of engines
and measure their performance
H Use various fuel mixtures on the engine and
measure its performance
J Use various fuel mixtures on many types of
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engines and measure their performance
In an investigation 10,000 dung beetles were Home
examined for the presence of parasites. The data
showed that about 5% of the beetles had
parasites. The results are —
The question
is only
about
parasites
dung beetles.
F invalid
because
only
dung
beetlesofwere
examined
Just because itbecause
was 5% doesn’t
mean it’s
wrong or
G unsupported
the parasite
population
unsupported.
was small
H erroneous
because
more
beetlesbut
should
have
The data may
have been
surprising
it is still
valid
the data was collected incorrectly or
hadunless
parasites
inconsistently.
J valid
because the sample size was sufficient for
accuracy
10,000 beetles is a very adequate sample
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size in which to make a valid conclusion.
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The following
boxes represent a
field. Which pattern
for collecting 10
samples would
Rule:
provide
the
best
Samples should
data
for
identifying
be collected as
the
typesas
of plants
randomly
in
a field?with no
possible,
chance of bias.
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A good experiment has:
A large sample group for lots of data.
One variable being tested.
In experiments,
benefit
of larger
One control a
group
not getting
thesample
variable.
sizes would be more —
A variables
B representative data
C time per group
D control groups
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Which of these is a hypothesis that can be
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tested through experimentation?
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You can measure amounts of bacteria
andincreases
you can measure
temperature.
growth
exponentially
F Bacterial
as temperature increases.
G A fish’s ability to taste food is affected by
can
the clarity of aquarium water. How
these be
H Tadpoles’ fear of carnivorous measured?
insect
If they can’t,
larvae increases as the tadpolesthen
age.
they
J The number of times a dog wags
are its tail
indicates how content the dog is.untestable.
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The owner of a pet store assures a
customer that if she buys only one female
hamster, she will not need to worry about
the hamster having offspring, because there
will be no male with which the female can
breed. What possibility is the pet-store
owner overlooking?
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Irrelevant unless the customer wants more
hamsters
eventually.
The
hamster
could be infertile.
F
Sex changes
do not
occur in hamsters.
G The
sex of the
hamster
could change.
If she
were pregnant,
will have more
H The
hamster
could the
becustomer
pregnant.
hamsters soon.
J The
hamster
be a twin.
Does
not applycould
to the customer.
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Home
The diagram shows different
setups of an experiment to
determine how sharks find their
prey. Which experimental setup
is the control?
FQ
In this case,
“normal” for
GR
sharks is the
HS
control.
JT
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Dr. Percy Lavon Julian(1899–1975)
Not many years ago, people with rheumatoid arthritis suffered greatly. Their joints Home
became swollen, inflamed, and painful, and many were unable to walk. Then doctors
found that a natural chemical called cortisone helped reduce the symptoms of
arthritis. However, cortisone was difficult to produce and too expensive for most
people to afford.
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Dr. Percy Lavon Julian, a chemist, came to the aid of people who suffered from
rheumatoid arthritis. Dr. Julian developed a synthetic form of cortisone from soybean
and yam plants. The synthetic form was easy to produce and affordable.
Dr. Julian found that soybeans provide other important chemicals as well. Using these
chemicals, he developed waterproofing materials and a foam used to put out fires.
The navy used this foam to protect ships and planes during World War II. Dr. Julian’s
work and the products he helped produce continue to improve the lives of thousands
of people.
Has a control
group
and large sample size.
A pet food company conducted an investigation using a new type of cat food.
Researchers measured several indicators of health in four groups of cats. Back to Home
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Each group was fed a different diet. After six months the researchers found
no difference in the health indicators among the groups and concluded that
the new food has no ill effects on cats’ health.
How could this investigation have been improved?
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Home
Ten different types of culture media were
inoculated with the same strain of bacteria and
incubated at the same temperature. Nine of the
cultures grew. Which of these conclusions can be
drawn from this information?
F The media used
in the experiment are all
th
Why didn’t the 10 dish grow bacteria?
capable of sustaining bacterial growth.
G The temperature varied greatly during the
Given: same temperature
experiment.
H Only
theinoculation
culture was
thatdone
failed
to grow bacteria was
Assume
consistently.
inoculated properly.
J One
of the
lacked
the
nutrients
Perhaps
one media
media (food)
wasn’t
suitable
for that needed
species
bacteria totogrow.
for
the ofbacteria
grow.
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Certain chemicals in the diet of moth
larvae seem to influence the early
development of the moths’ wings.
Careful observation of developing
pupae could result in —
Data may
may not
verify
the hypothesis.
A data
to or
verify
the
hypothesis
A conclusion to
is not
made
until a valid
B changes
the
conclusion
experiment has been completed.
C AaEggs
conclusion
about
moths’
eggs
new
species
are not included
means
comparison
in thethe
study.
of The
the moths
study
begins
being
with larvae
to known
and thespecies.
observations
Instead,
arethe
finished
experiment
when
Dobserved
development
of
a new
moth
species
was
wings
about
have
thisappeared.
moth species’ growth response to
certain chemicals.
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The smell of an ammonia solution
used to clean a floor can quickly be
detected throughout a house.
Scientists explain this phenomenon
by theorizing that gas molecules
from the ammonia are in continuous
random high-speed motion, drifting
rapidly and permeating the air.
Which statement best demonstrates
the strength of this theory?
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A Scientists have observed tiny smoke Home
particles moved by unseen particles in a
rapid, irregular fashion.
B Scientists have unanimously agreed on
this theory since Thomas Graham’s
experiments in the 1820s.
C The possibility of another theory being
formed to explain the phenomenon as well
is very remote.
D Reason, as opposed to experimentation,
is superior to any explanation found through
chemical testing.
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Starting in June, a student observed the animals in a compost pile over a period
of one year. In September the student removed as many centipedes from the
compost pile as she could find and released them in a park several miles away. At
the end of one year, there were many more spiders in the compost pile than had
been present the year before. There were also fewer springtails and beetles.
Which statement best explains why the populations of springtails and beetles
decreased?
A They had less food available to them.
B They had less space available to them.
C They faced increased predation by carnivores.
D They faced increased competition from herbivores.
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Use this info. for the next question.
Which conclusion about the frogs is
Home
supported by these data?
A Four frogs out of ten preferred the
40% does not equal 35%.
green area.
B The frogs randomly moved into
35%, 34%
are all close to 33% statistically.
the 31%,
colored
areas.
C Most frogs tended to avoid the
31%,
35%,
34%
are
all
close
to
33%
statistically.
red area.
Red was only 3% different than blue.
D Most frogs preferred the color
“Most” means over 50%. Blue section was 34%.
blue.
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For a science project a student decided to determine the preferred food
of birds called finches. He hung two feeders, one with sunflower Back to Home
sci. method
seeds and one with millet, from a tree at a height of 12 feet. He hung
two more feeders, one with sunflower seeds and one with millet, at a
height of 4 feet on the same tree. He counted the number of finches
at each feeder three times a day for five weeks. Based on his
observations, the student concluded that finches’ primary food
source is sunflower seeds. However, his science teacher questioned
the student’s conclusion. The teacher most likely questioned the
student’s conclusion because the student did not —
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Same kind of containers:
Same amount of water:
Different starting temperatures
The table shows times required for water to Home
evaporate from identical containers. Which of
these is the best question to ask before
developing a reasonable hypothesis to explain
the data?
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F Why does a lower temperature slow the rate of
evaporation?
G What is the boiling point of the water after both
samples are heated?
H Why does water exist as a solid at −15°C and
as a liquid at 25°C?
J How does the rate of evaporation change when
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a different container is used?
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This chart shows the results of an experiment performed in the 1920s using a
bacterial species that causes pneumonia in humans. The experiment
involved several procedures using two different bacterial strains, R and S.
What is a possible explanation for the results in Group 2?
A Living S-strain bacteria can transform into a pathogenic form of R-strain
bacteria.
B Living R-strain bacteria are controlled by a mouse’s immune system.
C Dead S-strain bacteria can cause disease.
D Dead R-strain bacteria can confer resistance to S-strain bacteria.
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A group of students set up two compost piles (A and B) that each contain the
same amount and type of dead organic material. Both piles are sheltered Back to Home
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from precipitation. Twice a week the students add water to Compost Pile A
but add no water to Compost Pile B. Once a week the students estimate the
numbers of different types of organisms in each pile by random sampling.
Which question are the students most likely trying to answer?
A How does the moisture level in a compost pile change over time?
B What types of organic material lead to the most-diverse compost-pile food
webs?
C Do more organisms live in compost piles with moist environments or dry
environments?
D How does the number of carnivores in a compost pile affect the number of
omnivores?
Objects of the same mass but of different sizes
and shapes were dropped from a given height.
Home
Their rates of free fall were measured and
recorded. Which of the following is most likely the
question this experiment was designed to
answer?
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All were
dropped
from
a “given
height”.
F How
does
height
affect
the
force of gravity?
G How
does
gravity
affect
objects of different
Density
is not
as important
in freefall
as wind resistance and Bernoulli's Principle
densities?
Massdo
is constant
the universe.
on
H How
mass through
and weight
affectWeight
fallingdepends
objects?
gravity
ofsize
the planet
you’re
on.affect an object’s rate
J How
do
and
shape
Objects were same mass, but different sizes and shapes
of free
fall?
which
could include objects with different kinds of wind
resistance and Bernoulli's Principle.
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This experiment probably was set
up to determine —
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A how much mechanical energy
the battery produces
B the pH of water during
electrolysis
C the pressure created by an
electric current
D how much energy is
converted to heat
A thermometer
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A scientist has hypothesized that the
existence of life on Mars is likely because
Mars’s atmosphere is 95% carbon dioxide.
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Which question is valid in testing this hypothesis?
F Do most other scientists agree with the
hypothesis?
G Could abiotic processes account for the carbon
dioxide?
H What is the percent of argon compared to
carbon dioxide in the Martian atmosphere?
J Have the scientist’s other predictions about
36
Mars been validated?
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This statement is a poor hypothesis because it
is not —
Beauty is a qualitative
A a question
observation that is very
B testable
opinionated.
Science considers qualitative
C observable
D a comparison observations and opinions as
invalid.
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As temperature drops to the dew point,
clouds form in the atmosphere, and Home
dew forms on ground surfaces. A
scientist proposes that adding more
measurable
water
molecules to the atmosphere will
measurable
change the dew
point. This proposal is
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A proposal comes before the experiment which
F an
invalid
comes
beforeobservation
the observation.
A proposal that is measurable is valid hypothesis.
G aBecause
valid hypothesis
it is measurable, it is valid although it may
You
don’t have
a valid conclusion
until
you have
be
proven
after
experimentation
to
be
incorrect.
H anobserved
invalidandproblem
analyzed a large sample size of data
J a and
valid
hadconclusion
a control group in which to set a standard.
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The diagram shows an experimental setup.
Which of these questions was this experiment designed to answer?
A Does water boil when exposed to air?
B Will fire turn a gas into a liquid?
C Does air expand when heated?
D Will heat turn a gas into a solid?
39
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Students placed equal amounts
of bread mold on 12 identical
agar plates containing the same
0oC
amounts
and types
22oC of nutrients.
45oC
o
Four plates were kept at 0 C,
o
four were kept at 45 C, and Four
were kept at 22oC (room
temperature). The plates were
examined after five days.
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Which of the following was probably the
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hypothesis for this experiment?
F The
growth of
bread mold
increases
Sometimes
a hypothesis
is disproved.
as temperature increases.
G The type of nutrient causes bread
All dishes had the same nutrients.
mold to grow faster at higher
temperatures.
All dishes
were
the same
size.
H The size
of the
plates
determines
the
temperature of bread mold.
J The
ofon
bread
mold is
The temperature
growth depended
the temperature.
determined by the mold’s growth.
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Sample A
started with
boiling
Less
time
Sample B
was never
boiled
More
time
Which is the best question to ask before developing a reasonable hypothesis
for the phenomenon shown above?
F Why does water crystallize into a solid below 0°C instead of remaining a
liquid?
G How will the freezing time from 20°C to –15°C change if each container is
covered?
H Why does boiling the water cause it to freeze more quickly when cooled from
20°C to –15°C?
J What is the precise boiling point of the water in Sample A after it has been
heated?
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Which of the following best describesHome
the question this set of procedures was
designed to answer?
A Can a substance from dead bacteria
transform living bacteria?
B Can R bacterial cells survive
heating?
C Can dead bacterial cells confer
immunity to a living host?
D Can bacterial cells be isolated from a
healthy host?
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