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# Variables 1568387899223 sc

```Name:____________
Exam #1 Variables
Pd:_________
1. Which statement best describes a controlled
experiment?
A) It eliminates the need for dependent variables.
B) It shows the effect of a dependent variable on an
independent variable.
C) It avoids the use of variables.
D) It tests the effect of a single independent
variable.
2. An investigation was designed to determine the effect
of ultraviolet light on mold spore growth. Two groups
of mold spores were grown under identical
conditions, except one group was exposed only to
ultraviolet light, while the other group was grown in
total darkness. In this investigation, the group of mold
spores grown without receiving any ultraviolet light is
known as the
A) control
B) hypothesis
C) dependent variable D) limiting factor
3. Which statement about the use of independent
variables in controlled experiments is correct?
A) A different independent variable must be used
each time an experiment is repeated.
B) The independent variables must involve time.
C) Only one independent variable is used for each
experiment.
D) The independent variables state the problem
being tested.
4. In a scientific investigation, after the question is
defined, the next step is most likely
A)
B)
C)
D)
formulating a hypothesis
identifying needed equipment
designing the experiment
collecting the data
5. Which sentence represents a hypothesis?
A) Environmental conditions affect the pollination
of plants.
B) Boil 100 milliliters of water, let it cool, and then
add 10 seeds to the water.
C) Is water depth in a lake related to available light
in the water?
D) A lamp, two beakers, and elodea plants are
selected for the investigation.
Date: 9/16/19
6. A biologist formulates a hypothesis, performs
experiments to test his hypothesis, makes careful
observations, and keeps accurate records of his
findings. In order to complete this process, the
biologist should
A) adjust the data to support the hypothesis
B) eliminate data that do not support the hypothesis
C) write a research paper explaining his theories
before performing his experiments, in order to
gain funding sources
D) evaluate the findings and, if necessary, alter the
hypothesis based on his findings, and test the
new hypothesis
Pd:_________
7. Base your answer to the following question on on the information below and on your knowledge of
biology.
An investigation is carried out to determine the effect of exercise on the rate at which a person
can squeeze a clothespin
In this investigation, the independent variable is the
A) control
C) rate of squeezing
B) exercise
D) number of participants
8. In an experiment, what should be the relationship
between the control group and the experimental
group?
A) They should be different in size
B) They should resemble each other in at least two
respects
C) They should not be similar in any respect
D) They should be identical in all respects except
one
9. A new drug for the treatment of asthma is tested on
100 people. The people are evenly divided into two
groups. One group is given the drug, and the other
group is given a glucose pill. The group that is given
the glucose pill serves as the
A) experimental group B) limiting factor
C) control
D) indicator
10. Base your answer to the following question on the information below and on your knowledge of
biology.
An experiment was carried out to answer the question &quot;Does the pH of water affect the growth
of radish plants?&quot; Two groups of ten radish plants were set up. One group was watered with water
having a pH of 3.0, and the other group was watered with water having a pH of 7.0. Both groups
of plants received the same amount and intensity of light, the same amount of water, and they
were grown in the same type of soil. The heights of the radish plants were measured every 2 days
for a period of 2 weeks.
What was the dependent variable in this experiment?
A) heights of the plants
C) temperature of the water
B) pH of the water
D) type of soil
Pd:_________
11. Base your answer to the following question on the
information and diagrams below and on your
knowledge of biology.
An experiment was performed to determine the
effect of different mineral salts on plant growth.
Forty pots containing identical plants were divided
into four equal groups and placed in a well-lighted
greenhouse. Each pot contained a nonmineral potting
medium and one plant. Materials were then added to
each experimental group of pots as shown
What was added to the control group of pots?
A)
B)
C)
D)
water, only
nitrogen salts, only
potassium salts, only
potassium and phosphorus salts
12. How does the CONTROL GROUP setup in an
experiment differ from the other setups in the same
experiment?
A) It tests a different hypothesis.
B) It has more variables.
C) It does not receive the experimental treatment
(Independent Variable).
D) It utilizes a different method of data collection.
13. A new concept that is tested in a scientific
investigation is known as
A) a theory
C) an inference
B) the hypothesis
D) an observation
14. In the lab activity Making Connections, an experiment was designed to test the effect of exercise on
the ability to squeeze a clothespin. The number of times the clothespin was squeezed served as the
A) independent variable
C) hypothesis
B) dependent variable
D) control
Pd:_________
15. In an appropriately designed experiment, a scientist
is able to test the effect of
A)
B)
C)
D)
a single variable
multiple variables
the hypothesis
scientific observations
Base your answers to questions 16 and 17 on the information and diagram below and on your
knowledge of biology.
The presence of air is believed to be important for root growth in bean plants. The apparatus
available to conduct an investigation is shown below. There are enough bottles and other materials
to have multiple setups. Air (for aeration) can be bubbled into the bottle through the rubber tube.
Design an experiment to test the effect of aeration on the growth of roots of bean seedlings. In your
answer, be sure to:
16. Describe how the control group will be treated differently from the experimental group.
17. Identify the dependent variable in the experiment.
Pd:_________
18. Base your answer to the following question on information and diagram below.
An investigation was carried out using the two setups shown below. Other than the difference shown
in the diagram, all other conditions were identical.
a State one possible hypothesis that could be tested using these setups.
b What data should be collected in order to test the hypothesis stated in question a?
19. Base your answer to the following question on the data table and information below and on your
knowledge of biology. The data table describes various pH levels.
A scientist is concerned about the effects of acid rain on newly fertilized fish eggs in lakes in
the Adirondack Mountains of New York State. The scientist would like to investigate the hatching
rates of these fish eggs in water at different acidic pH levels. The scientist designed an experiment
that could show the effect of an acid pH on the hatching of these fish eggs.
State two factors that must be kept the same in both the experimental groups and the control group.
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