Name Date Review Packet for Scientific Method Unit Exam 1... · Review Packet for Scientific Method...
Transcript of Name Date Review Packet for Scientific Method Unit Exam 1... · Review Packet for Scientific Method...
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Review Packet for Scientific Method Unit Exam
Terms related to the parts of a controlled experiment: Match the term with its definition.
__A___controlled experiment
A) sets up experimental groups to determine how two factors are related. In
the experiment, all factors must be the same in every way possible except for
one variable that is tested (independent variable.)
__F___variable
B) the factor that you measure to gather your results.
_D____independent variable
C) a testable explanation for your problem. It is stated in an If and then
format.
_B____dependent variable
D) the variable that is manipulated or changed by the scientist. It is also called
the experimental variable.
_C____hypothesis
E) occurs when an organism is in a balanced, steady state and is healthy.
_H____constants
F) any factor in a controlled experiment that can change.
_G____control group
G) a group that is tested with “normal” conditions, without the independent
variable, and used for comparison.
_E____homeostasis H) are all of the factors that are the same in all the subjects of the experiment.
An Example of a Controlled Experiment: A scientist wants to study the effect of the amount of sunlight on plant growth. She puts plants in a room
with no sunlight, plants in a room with direct sunlight, and plants in a room with indirect sunlight. She
records the height of the plants at the beginning of the month and at the end of the month.
How do we analyze the experiment?
In this experiment, the independent variable is the amount of light the plants received. The dependent
variable is the amount of plant growth measured. The constants are the same in all three rooms: type and
age of all plants, amount of water they receive daily, and temperature and humidity levels. The controlled
group is the plants in the room with the indirect sunlight (normal conditions.)
The Scientific Method: Analyzing the Parts of an Experiment:
Experiment #1
Karen does an experiment to see what kind of two fertilizers she uses will make her plant grow faster. She
bought the “Stop and Shop” brand and “Miracle Grow” brand and put the same amount into two identical
plants. They were put on the same window sill. She wanted to see which one would grow faster after two
weeks.
These were her observations, which she recorded in the following data chart:
Fertilizer Brand Growth after one week(cm)
Stop and Shop 3cm
Miracle Grow 7cm
Answer the questions that follow based on Karen’s experiment.
1. What is the proper
way to write a
hypothesis? Write a hypothesis
for Karen’s
experiment
If the ____________________ (increases, ) then the _____________ would
____________________, ___________________, or _________________.
If Stop and Shop fertilizer is used, then the plant
will grow faster.
2. What is the
independent
variable.
(Remember: “I
change…”)
Type of fertilizer (Miracle Grow/ Stop and Shop
fertilizer)
3. What is the
dependent variable.
( Remember: D for
data)
What measuring tool
should she use to
collect her data?
How fast the plant grows.
How tall the plant grows in one week.
4. What are the
constants in this
experiment?
(Remember: S for
“the same”)
Same plant
Same window sill
Same amount of fertilizer in each plant
5. Karen is missing a
control group. What
should she do?
A plant with NO FERTILZER
6. What do we mean
by the validity of an
experiment? What
would make this
experiment more
valid
How true the results are.
Larger sample size, control group, more trials
7. What is the
sample size of this
experiment?
Should it be small or
large? Why
2 plants!!!!
LARGE!!!
8. What is Karen’s
conclusion for this
experiment?
The plant given Miracle Grow grows faster. It
grew to 7 cm.
Experiment #2:
A student buys a new electronic toy. In the store he notices different brands of batteries. He wants to know
which battery will last the longest, so he designs a controlled experiment. He buys four types of batteries.
One type of battery is placed into the toy. He records the exact number of minutes the toy works until the
battery runs out. Then he replaces the battery with a different type of battery, and again records the time it
takes for the battery to run out. He repeats it for all four brands of batteries.
Independent variable ___TYPE OF BATTERY_____________
Dependent variable ___MINUTES THE TOY WORKS_____
Constants ___SAME TOY
Experiment #3:
A teacher would like to know if increasing the amount of homework problems each night will increase her
students’ performance on tests. She decides to give 5 extra homework problems each night to 2 of her 5
classes, and 10 extra homework problems to the other 2 classes. The 5th class will get no extra homework.
She will measure the performance of the students on the test the following week.
Identify the following:
Problem DOES INCREASING THE AMOUNT OF
HOMEWORK PROBLEMS INCREASE TEST
PERFORMANCE? Hypothesis IF A CLASS IS GIVEN MORE HOMEOWRK,
THEN THEY WILL SCORE HIGHER ON THE
TEST. Independent variable AMOUNT OF HOMEOWRK
Dependent variable THE TEST GRADES
Constants SAME TYPE OF PROBLEMS, GIVEN ON
SAME NIGHT, GIVEN SAME TEST
Control group The 5th CLASS GIVEN NO HOMEWORK
Graphing: A biology class conducted an experiment to determine the rate of respiration of yeast in bread dough at
various temperatures. Bread dough will rise due to the production of carbon dioxide by the yeast present in
the dough. An equal amount of dough was placed in the bottom of each of five graduated cylinders. Each
cylinder was then placed in a different water bath to maintain a particular temperature. A diagram of the
setup is shown below.
The amount of expansion of the dough in each cylinder was measured after 15 minutes.
The results are shown in the data table below.
Directions (10–11): Using the information in the data table, construct a line graph on the grid, following the
directions below.
10. Mark an appropriate scale, without any breaks, on the axis labeled “Temperature of Water Bath (°C).”
11. Plot the data from the data table. Surround each point with a small circle and connect the points.
Measuring: 1. What is the approximate length of the earthworm shown in the diagram below?
(1) 9 mm (3) 10.6 cm
(2) 90 mm (4) 106 cm
2. A= _______0.6_____cm = ____.006__________ m
3. D= ______3.7______cm = ____.000037________km
4. F= ______6.7_______cm = _____67___________mm
3. ______21.5____________________ mL
21.5
4. _______44______ °C
cm
There is no control group. There is no
group NOT given the Auxin/Growth
Hormone
15 shrews
How to solve: Find 500,000 on the x-axis, read up to where it meets your line for
shrews (with circles), read across to find the answer on the y-axis.
1. Which statement about the use of independent variables in controlled experiments is correct?
(1) A different independent variable must be used each time an experiment is repeated.
(2) The independent variables must involve time.
(3) Only one independent variable is used for each experiment. (4) The independent variables state the problem being tested.
2. The development of an experimental research plan should not include a
(1) list of safety precautions for the experiment
(2) list of equipment needed for conducting the experiment
(3) procedure for the use of technologies needed for the experiment
(4) conclusion based on data expected to be collected in the experiment
3. A biologist used the Internet to contact scientists around the world to obtain information about declining
amphibian populations. He was able to gather data on 936 populations of amphibians, consisting of 157
species from 37 countries. Results showed that the overall numbers of amphibians dropped 15% a year from
1960 to 1966 and continued to decline about 2% a year through 1997.
What is the importance of collecting an extensive amount of data such as this?
(1) Researchers will now be certain that the decline in the amphibian populations is due
to pesticides.
(2) The data collected will prove that all animal populations around the world are threatened.
(3) Results from all parts of the world will be found to be identical.
(4) The quantity of data will lead to a better understanding of the extent of the
problem.
4. The first trial of a controlled experiment allows a scientist to isolate and test
(1) a logical conclusion
(2) a variety of information
(3) a single variable
(4) several variables