PSSA Science Practice Exam
{Answer Key}
The Nature of Science
Processes and Procedures of Science
Systems
Change in Systems
Patterns
Models
Tools in Science
Designing an Experiment
Data Analysis
Physical Sciences
Properties of Matter
Chemical Changes
Forms and Sources of Energy
Energy Transfer
Energy Resources
Force, Motion, and Newton’s Laws
Simple Machines
Earth and Space Sciences
Processes That Change the Earth’s Surface
Soil
Water on Earth
Effects of Humans on Earth’s Resources
Weather and Climate
Earth and the Solar System
TEST TAKING STRATEGIES
Essay / Open-Ended Questions
Read the essay/open-ended and look for the key verb. Every essay/open-ended
question centers on a key verb, which suggests the correct approach for developing your
answer. Here are some examples of key verbs:
Analyze – To break an idea or concept into parts in order to determine their nature and
relationships.
Compare – To state similarities
Contrast – To state differences
Define – To explain what something is or means
Describe – To illustrate something in words or tell about it
Discuss – To make observations using facts, reasoning, and argument; to present in some
detail
Explain – To make plain or understandable
Show – To clearly state and support position or idea
Keep the following strategies in mind when answering essay/open-ended questions:
1. Read the entire question through first.
2. Make a brief outline. Include all the main ideas you want to cover.
3. Write a thesis statement. A thesis statement states the topic of the essay and the main
ideas.
4. Write one paragraph about each main idea. Each main-idea paragraph should include
a topic sentence and supporting details. Use examples, description, or discussion to
elaborate on the supporting details.
5. Make sure your essay has a strong conclusion. Each should be a fully-developed
paragraph.
6. Read your essay and correct errors in spelling, grammar, and punctuation.
Multiple-Choice Questions
1. Read the entire question carefully.
2. Read all of the choices provided as possible answers.
3. Think: Re-read, look for clues, and make certain that you understand the question
and the choices provided as possible answers.
4. Eliminate the answer choices that you know are incorrect.
5. Think: Choose the best answer to the question.
Analyzing Graphs
1. Read the title of the graph.
2. Read the labels.
3. Examine the key, if any. Note colors, patterns, or shading. Study how they are shown
on the graph.
4. Read the test question about the graph.
5. Choose the best answer.
Analyzing Maps
1.
2.
3.
4.
5.
6.
7.
Identify the map’s title, key, scale, and compass rose. Always read the map title first!
Determine what type of information the map presents.
Read the multiple-choice question that goes with the map.
Decide which part of the map will help you find the answer.
Answer the question in your own words without looking at the answer choices.
Eliminate the answer choices that are obviously wrong.
Choose the best answer.
Scientific Investigations
Whether scientists do experiments, make models, or study natural processes by making
observations, all scientists follow some similar steps in their investigations. Although all
scientists use these steps, they do not all use them in the same order. For example, a
scientist usually needs to learn/research what others know about a topic before they know
what questions to ask. The steps scientists use include the following:







asking questions and making predictions {hypothesis}
learning about others’ work
planning investigations
making observations and collecting data
developing and using models
Analyzing observations or data.
{Used by scientists to infer, or make a guess based on evidence as to what happened
during the investigation.}
 drawing conclusions
 describing work to others
1. Which of the following statements could not be a scientific theory?
A. Burning coal increases the amount of carbon dioxide in the atmosphere.
B. Planting grass on topsoil prevents erosion of the soil. * Theories are supported by
C. Black pepper tastes better than white pepper.
evidence, opinions are not.
D. Plants grow better when nitrogen is added to the soil. Letters A, B, and D are
supported by evidence.
2. A student wants to do a scientific investigation to answer the question, “Does
fertilizer in soil affect how fast plants grow?” What will the student most likely
do first in this investigation?
A.
B.
C.
D.
Collect data on how quickly plants grow with and without fertilizer. *Step # 4
Hypothesize that fertilizer will make plants grow more quickly. *Step # 2
Read articles about how fertilizer affects plants.
Draw a conclusion about how fertilizer affects plant growth. * Step # 7
3. The student infers that fertilizer makes plants grow more quickly. Which of
the following observations best supports his inference?
A.
B.
C.
D.
After 2 weeks, most of the plants in the pot with fertilizer had died.
After 2 weeks, plants in the pot with fertilizer were healthier.
After 2 weeks, the plants in the pot without fertilizer flowered.
After 2 weeks, the plants in the pot with fertilizer were larger than the plants
in the pot without fertilizer. * Only choice D addresses the growth of the plants.
4. In question #3, the plant investigation, what is the independent variable?
A.
B.
C.
D.
the plant
the amount of water
the fertilizer This is the only choice that was changed in the experiment.
the amount of sunlight given
5. The dependent variable in the plant investigation of question #3 is:
A. the fertilizer = independent variable
B. the size of the plant - changed based upon how much fertilizer was used
C. the size of the pot
D. the soil the plant is in
6. A student puts a plant, a tin cup, and a washcloth on a desk. Which of these
best explains why the plant, cup, and washcloth are not a system?
A.
B.
C.
D.
Some of the items are man-made.
The items are not the same size.
The items do not operate on electricity.
The items are not working together to produce a result.
* Systems must work to produce a result. Choices A, B, and C describe the characteristics of the items of the
system, not the result that they produce.
7. The carbon cycle is a closed-loop system because no extra carbon comes into the cycle, and no carbon
leaves the cycle. Which of the following is the best example of a part in a closed-loop system?
A.
B.
C.
D.
the ink in a ball point pen *Ink flows out of the pen and does not go back in.
the cars on a large state highway *Cars enter and leave highways.
the electricity in a complete electrical circuit
the information in a desktop computer *Information enters and leaves a computer.
8. The food chain is an example of an open-loop system. Energy flows through the chain from one part
to another, but it does not cycle back through the food chain. Which of the following gives the levels
of organization in the food chain from the beginning of the system to the end of the system?
A.
B.
C.
D.
grass, sun, frog, grasshopper
sun, grass, grasshopper, frog *Energy enters the system as sunlight, but never flows back
frog, grasshopper, grass, sun into the sun.
grasshopper, grass, frog, sun
9. Most systems have inputs, processes, and outputs. Which of these is most likely an input to a river
system?
A.
B.
C.
D.
a flood *A flood is a condition that exists within a watershed. Watersheds help prevent floods.
a waterfall *A waterfall is part is a process that occurs in a stream or river.
rain *Watersheds funnel water from surface runoff of precipitation into streams and rivers.
erosion *Erosion is a process that occurs as a result of surface runoff.
10. Many systems in the human body are regulated by feedback-controlled systems. In feed-back
controlled systems, the output of the system determines when the system shuts down. For example,
the chemical insulin breaks down sugar in the blood. When there is too much sugar in the blood, the
body produces more insulin. When the level of sugar decreases, the body stops releasing insulin into
the blood. Which of these is an example of a feedback-controlled system?
A. the burner on a stove * The burner of a stove does not turn off when the food is finished cooking.
B. a thermostat on a heater *The heater output determines when the heater will shut off.
C. volume control on a television *The volume control on a TV does not shut off when the TV is too
loud.
D. a light switch * The light switch does not determine when the light is no longer needed.
11. Physical patterns have an object or design that repeats. Which of these is an example of a physical
pattern in nature?
A. A bee builds a honeycomb made of recurring hexagonal cells.
*This is a Physical pattern because the hexagonal cells are a repeating design.
B. A tree loses leaves in the fall and grows new leaves in the spring.*Temporal Pattern
C. A roof is supported by a repeating framework of wooden trusses.
*This is an example of a physical pattern, but it does not occur naturally.
D. A computer automatically saves information every five minutes. *Temporal Pattern
12. Temporal patterns repeat over a certain period of time. Which of these is not an example of a
temporal pattern?
A.
B.
C.
D.
animals migrate when seasons change * As the seasons change, animals migrate.
the rise and fall of ocean tides * Ocean tides change every six hours.
the moon changing phases * The appearance of the moon changes in a cycle of 29.5 days.
the repeating arrangement of atoms in a crystal *The arrangement of atoms in a crystal
does not change over time.
13. Which of the following is an example of a structural pattern?
A.
B.
C.
D.
the arrangement of silk threads in a spider web *Repeating design or object.
how weather patterns change with the seasons
the rise and fall of sea level with changing tides
the apparent shapes of Venus throughout the month
*B, C, & D are examples of temporal patterns. These patterns change over time. The patterns are not structural.
Models are used by scientists and engineers to test new ideas, find solutions to problems, develop new
technologies and products, and to explore relationships between objects, systems or ideas.
Use the table below to answer question # 14&15.
*This Informational chart will not be provided on the actual PSSA test.
EXAMPLES OF MODELS
Blueprint
Full-Scale 3D Model
A process of photographic printing, used chiefly in copying architectural and
mechanical drawings, which produces a white line on a blue background.
A Full-Scale 3-D Model is a representation or copy of an object that is exactly
the same size as the object being represented.
A representation, usually on a flat surface, as of the features of an area of the
Map
earth.
Computer
Simulation
The technique of representing the real world by a computer program; "a
simulation should imitate the internal processes and not merely the results of
the thing being simulated"
14. An engineer is trying to determine how a particular bridge structure will hold up during an
earthquake. Which kind of model is he most likely to use to test his design?
A.
B.
C.
D.
a blueprint *A blueprint can’t be subjected to earthquake conditions.
a full-scale 3-D model *Too large, expensive, and dangerous to use.
a computer simulation *Lets the engineer manipulate the conditions the real bridge might face.
a map of earthquake zones * Would give you no information about bridge design.
15. Scientists in the automobile industry collect a lot of data about the average heights and weights of
people of different ages and body types. What is the most likely reason they collect so much data?
A. to determine at what scale they should develop their vehicle blueprints
* The accuracy of blueprints depends on the amount and accuracy of the data collected, not the scale at which
it is presented.
B. so that they can use data instead of models for safety testing
* Data is used to produce safety models, not instead of models.
C. to make their models for safety testing as accurate as possible
D. so that their models do not have to make assumptions
* Models are not based on assumptions, they are are based on observations and data.
16. A scientist is designing an experiment to test the effects of pollution from a coal mine on the growth
of native frogs. How will the scientist most likely choose to evaluate the effect of the pollution?
A. by counting the relative numbers of males and females in wild and captive
Populations * The number of males versus females has nothing to with growth.
B. by comparing the average length of frogs in experimental groups exposed to
pollution to that of frogs in a control group
C. by comparing the numbers of dead frogs in the wild to those in a laboratory
control group * The mortality rate of the frogs has nothing to so with their growth.
D. by describing how healthy the frogs in the experimental groups exposed to
to pollution are * The health of the frogs does not address their growth patterns.
17. Many farmers have started using natural predators such as ladybugs to control crop pests. What
will be the most likely benefit of this practice to human health?
A. increased availability of water due to drought-resistant crops
* Controlling crop pests by using natural predators has nothing to do with engineering drought-resistant crops.
B. fewer respiratory problems because of lower exposure to chemicals
*Health benefits to organisms that breathe in air. {Fewer pesticides to breathe in}
C. better nutrition resulting from changing the genetic makeup of the crops
* Controlling crop pests by using natural predators has nothing to do with changing the genetic make up of crops.
D. decrease in levels of hunger around the world due to crops with larger fruits
* Using natural predators has nothing to do with producing crops with larger crops.
Observe the graph below and answer the question that follows.
time on x-axis
18. The graph shows that, as time increases,
A. the overall salinity percent increases as time increases * decreases not increases as time passes.
B. the overall salinity percent does not change as time increases *decreases, does not remain constant
C. the overall salinity percent decreases as time increases *Inverse relationship: As time increases,
The salinity percentage decreases.
D. the overall salinity percent cannot be determined.
The circle graph (or pie chart) below shows the results of a question asked to 270 job
holders. Those surveyed were asked by what means they travel to work.
19. Which of these conclusions is best supported by the data in the graph?
A.
B.
C.
D.
The best way for job holders to travel to work is by car. *Best how?
Job holders prefer vans more than motorbikes. *Opinion not supported by graph.
Buses are the most expensive way to travel to work. *Not supported by graph.
The majority of job holders travel to work by car. * The data shows that most workers travel
to work by car.
A student moves from the city to a house along the coastline. He thinks it is cooler at his new beach
house than it was in the city. The boy does research and finds information on daily temperatures in the
city and at the beach. He records his data in the table seen below.
Date
Temperature in
the City {Degrees C}
Temperature at
the Beach {Degrees C}
June 20th
June 21st
June 22nd
June 23rd
June 24th
June 25th
June 26th
31.0
33.5
35.3
32.8
33.4
34.0
36.4
29.7
31.6
32.7
29.9
29.8
31.6
34.2
20. What conclusion can the student draw from his data?
A.
B.
C.
D.
It is always warmer in the city than at the beach. *Always?
It is always warmer at the beach than in the city. *Not supported by data. Always?
It was warmer in the city than at the beach this week.
It was warmer at the beach than in the city this week. *Not supported by data.
Use the table found below to answer questions # 35 and # 36. {Chart NOT Provided on PSSA}
Form of Energy
Kinetic
Mechanical
Heat
Potential
Chemical
Nuclear
Electrical
Light
Sound
SUMMARY OF ENERGY FORMS
Description
Energy of motion
Kinetic energy plus potential energy
Energy that moves from hot objects to cooler ones
Energy of position or shape
Energy stored in chemical bonds
Energy stored in the nucleus of the atom
Energy of moving electrons
Energy contained in electromagnetic waves
Energy produced by vibrating objects
21. What determines the potential energy of an object?
A. its motion *Kinetic
B. the vibrations of its particles
*Sound
C. the movement of the electrons
D. its position
*Electricity
22. A potato and a battery are sitting on a bench. What form of energy do both the potato and
the battery have?
A. electrical energy * energy of moving electrons C. kinetic energy * The potato is not in motion.
B. chemical energy * Foods contain molecules D. sound energy *The potato does not produce sound.
of proteins, fats and sugars. When we eat these
foods, our bodies break apart these molecules and
use the energy from them.
Energy can be transferred from one place to another in different ways. The 3 ways energy can move are
conduction, convection, and radiation. In conduction, energy is transferred within an object or between
objects that
are touching. In convection, flowing fluids (flowing matter) transport energy from one place to another. Unlike
conduction and convection, radiation does not require matter. In radiation, waves transfer the energy.
Radiation can transfer energy through matter or through empty space.
23. A student is holding an ice cube in her hand. Which of the following describes the energy transfer
that will most likely occur?
A.
B.
C.
D.
Energy will move by conduction from her hand to the ice. *Ice is in contact with her hand.
Energy will move by convection from the ice to her hand. * Heat transfer within a fluid.
Energy will move by convection within the ice. * Convection occurs in fluids, not solids.
Energy will move from her hand to the ice by radiation. Human hands do not produce
radiant energy.
Use the table found below to answer question # 24.
DENSITIES OF FOUR METALS
Metal
Density
Aluminum
2.7g/cm3
Copper
8.9 g/cm3
Lead
11.3 g/cm3
Iron
7.9 g/cm3
24. A student has a piece of copper, a piece of aluminum, a piece of lead, and a piece of iron.
All four pieces of metal have the same volume. Which statement about the masses of the pieces
is most likely true?
A.
B.
C.
D.
The piece of lead has the greatest mass.
All of the pieces have the same mass. *All will have different masses because their densities differ.
The piece of iron has a smaller mass than the piece of aluminum. Al = the smallest mass
The piece of aluminum has a greater mass than the piece of copper.Cu mass > Al mass
25. Which of the following substances is a compound?
A. solid gold (Au) *Element
C. nitrogen gas (N2) *Element / Simple Molecule
B. liquid sulfuric acid (H2SO4) D. liquid mercury (Hg) *Element
26. Which of the following substances is a molecule, but not a compound?
A. solid magnesium (Mg)
*Element
C. hydrogen gas (H2) *Element and
Simple Molecule
B. liquid water (H2O) *Compound
D. solid table salt (NaCl) *Compound
Gravitational Potential Energy = Weight x Height
27. A postal worker lifts several packages to different heights. Which package has the greatest
gravitational potential energy after the postal worker lifts it?
A.
B.
C.
D.
a 4-Kg package lifted 1.5 m above the ground *4Kg x 1.5m = 6 Kgm
a 6-Kg package lifted 3 m above the ground *6Kg x 3m = 18 Kgm
a 3-Kg package lifted 2 m above the ground *3Kg x 2m = 6 Kgm
a 1-Kg package lifted 2.5 m above the ground *1Kg x 2.5m = 2.5 Kgm
28. A bowler is holding a bowling ball in the air. The ball is not moving. Gravity is pulling the ball
downward with a force of 44 N. What is the size of the upward force the bowler is applying to the
ball?
A. 11 N
B. 22 N
C. 44 N
D. 0 N
*Equal / Opposing Force Upward
The diagram below shows an incomplete circuit.
29. Which item would allow the bulb to light up if it were used to connect point A to point B?
A.
B.
C.
D.
a glass rod - would not conduct electricity.
a metal coin – the metal in the coin would conduct electricity.
a plastic comb – would not conduct electricity.
a paper cup – would not conduct electricity.
30. Hydrochloric acid is added to a beaker containing a piece of zinc. As a result, zinc chloride
is formed and hydrogen gas is released. This is an example of:
A.
B.
C.
D.
a chemical reaction - two substances are added together and the resulting substance is completely different.
a physical change - would simply be a change of form, not a change of substance.
photosynthesis – plant creating food.
evaporation – phase change from liquid to a gas.
31. During which phase change is heat energy absorbed by a substance?
A.
B.
C.
D.
liquid to gas *Evaporation
gas to solid
liquid to solid
gas to liquid
32. Which statement best describes the property of light waves illustrated in the diagram
below?
A. Some materials absorb light waves.
B. Some materials reflect light waves.
C. Light waves are refracted by some materials. *The refracted light makes the pencil
appear to be bent.
D. Light waves are emitted by some materials.
The diagram below shows a stationary cart on a frictionless surface. Two unequal opposing forces are
about to be applied to the cart.
33. If the unequal opposing forces are applied to the cart at the same time, what will occur?
A. The cart will move to the left.
B. The cart will move to the right. *360 newtons of force is the greater force, so the cart
would move to the right.
C. The cart will alternate between moving left and right.
D. The cart will remain stationary.
Base your answers to the following questions on the graph below, which shows the solubility (amount that
will dissolve in 100 grams of water) of three substances at various water temperatures.
34. Which statement is a correct interpretation of the data in the graph?
A. As water temperature increases, solubility decreases.
B. As water temperature increases, solubility increases.
*As the temperature of the water increases, so does the solubility of the substances. Since warm water
is less dense, there is more space for the solute.
C. As water temperature increases, solubility increases and then decreases.
D. As water temperature increases, solubility decreases and then increases.
35. As the water temperature is increased from 30oC to 70oC, how many more grams of
substance A will dissolve in 100 grams of water?
A. 20 g
B. 40 g
C. 50 g
D. 90 g
36. Which diagram represents electromagnetic energy with the shortest wavelength?
A.
B.
C.
D.
A
B *Wavelength refers to the distance between wave crests (or peaks).
C
D
37. A coffee mug is sitting on a table. It is not moving. Which of these statements about the cup
must be true?
A.
B.
C.
D.
Gravity is not acting on it. *gravity works on all objects on the Earth regardless of their position.
Friction is not acting on it. * Friction is one of the forces acting on the mug preventing it from moving.
Unbalanced forces are acting on it. * Balanced forces are working on the mug so it does not move.
Balanced forces are acting on it. *The table offers an upward force equal to the downward force of
of gravity.
Use the table found below to answer question # 38.
Layer
1
TYPES OF FOSSILS FOUND IN DIFFERENT SEDIMENT LAYERS
Age of Layer
Type of Sediment
Type of Fossil
1 million to 3 million years
coarse, light-colored sand
sea bird bones
2
3 million to 6 million years
fine, light-colored sand
crab and clam shells
3
6 million to 10 million years
very fine, dark-colored silt
sea urchin shells
4
10 million to 12 million years
extremely fine, dark-colored clay
fish bones
38. A geologist studied the fossil content of several layers of sediment trying to determine what kind of
environment existed in the area in the past. Based on the geologist’s observations recorded in the
table above, which of these descriptions of the ancient environment is most likely true?
A. Between 6 million and 10 million years ago, the area was a rocky plateau.
*Sea Urchins can not exist on a rocky plateau.
B. Between 10 million and 12 million years ago, the area was a jungle.
*Fish do not naturally exist in a jungle habitat. If there were bones, they would have had to be put there.
C. Between 3 million and 6 million years ago, the area was an ocean beach
D. Between 1 million and 3 million years ago, the area was covered by a deep
ocean. *Sea birds are land animals.
39. In which type of rock are fossils generally found?
A.
B.
C.
D.
igneous - fossil would be melted in magma/lava.
metamorphic – fossil would be destroyed by heat and pressure.
sedimentary – most likely to preserve because of how a sedimentary rock forms.
volcanic – formed from molten material.
40. In a certain location, a scientists notices that the soil’s parent material is different than its bedrock.
What two processes are most likely responsible for this?
A.
B.
C.
D.
erosion and deposition
deposition and freezing
weathering and freezing
condensation and precipitation
* The soil particles were eroded and transported from somewhere
else prior to being deposited.
41. There are granitic rocks in Gettysburg, Pennsylvania. Based on this, what is the best conclusion
a geologist can draw about that region?
A.
B.
C.
D.
An ocean once covered that region.
There was once reverse faulting in that area.
Dinosaurs once inhabited that region.
There was once molten rock below the ground in that region.
* Granitic igneous rocks form from molten material that cools beneath the Earth’s surface.
42. Australia is located in the southern hemisphere. What are probably the coldest months
in Australia?
A.
B.
C.
D.
March, April, and May
June, July, and August * opposite of the season currently occurring in the northern hemisphere
September, October, and November
December, January, and February
Type of Eclipse
Positions of the Sun, Moon, and the Earth
Lunar Eclipse
Solar Eclipse
43. On August 28, 2010, a full lunar eclipse was visible over most of Pennsylvania.
What phase was the moon most likely in on the 21st of 2010?
A. new moon
B. first-quarter
C. last-quarter
D. full moon *The Earth must be between the
sun and the moon so that the
full moon can move into the
shadow cast by the Earth.
44. Which statement best explains why the Sun and the Moon appear to be about the same
size in the sky?
A.
B.
C.
D.
The Sun and the Moon have the same diameter.
The Moon is larger in diameter and farther from Earth than the Sun.
The Moon is smaller in diameter and is closer to Earth than the Sun.
The Sun and the Moon are the same distance from Earth.
45. Which two factors determine the gravitational attraction between two objects?
A.
B.
C.
D.
time and temperature
shape and orbital speed
color and hardness
mass and distance apart
46. Earth’s weather is primarily caused by the:
A.
B.
C.
D.
drifting of Earth’s crustal plates
gravitational attraction of the Moon
uneven heating of Earth’s surface
changing distance between Earth and the Sun
47. Which of these is an example of condensation?
A. water vapor floating in the air
B. snow falling
C. rain collecting in a lake
D. a cloud forming
The map below shows an air mass that formed over the Gulf of Mexico at location A.
48. Once air mass A reaches location B, the weather conditions at location B will most likely be:
A. warmer and drier - would have formed over land where it is warm.
B. warmer and more humid – air mass originates over water where it is warm.
C. colder and more humid – would have formed over cold water.
D. colder and drier – would have formed over land that where it is warm.
49. A coal mining company wants to build a mine in the watershed of a river that provides water for
a nearby town. Which of these will most likely be an effect of building the mine in that location?
A.
B.
C.
D.
The air will become cleaner. * The air would become more polluted if it is changed at all.
More fish will live in the river. * Less fish will be able to survive if the river becomes polluted.
The river will become polluted. * The river will become polluted from acid mine runoff.
More coal will form near the mine. * The coal being mined finished forming long ago.
50. Using tractors and other machines has made farming more efficient and has increased
farmers’ crop yields. Which of these is another affect of using machines on farms?
A.
B.
C.
D.
decreased soil erosion
increased oil depletion
decreased air pollution
increased pest damage
51. How does hydroelectric power help decrease the rate of global warming?
A. It does not rely on sunlight energy. * Solar power relies on the sun and does not contribute to global
warming.
B. It removes greenhouse gases from the atmosphere. *Doesn’t remove but doesn’t add them.
C. It does not add carbon dioxide to the atmosphere.
D. It lowers the sea level. * Hydroelectric power does not lower sea level. It will help prevent a rise in sea
level because hydroelectric power does not burn fossil fuels which contribute to
global warming.
52. Moving water in a river is considered a renewable resource because it:
A.
B.
C.
D.
carries dissolved oxygen.
easily erodes sediments.
is made of natural gas.
can be recycled by nature over time.
53. Which of these energy sources is nonrenewable?
A. wind power * Renewable
B. wood * Nonrenewable resources form very slowly and
*A, C, and D Renewable / Unlimited in Supply
C. solar power * Renewable
D. hydroelectric power Renewable
can’t be replaced in a human lifetime.
54. Which of the following best describes the process of transpiration?
A.
B.
C.
D.
precipitation soaking into the ground * percolation
evaporation of water by plants, crops, and trees
the freezing of liquid water to ice * freezing
the formation of hail * freezing
55. The structures found in a living cell can be compared to the parts of a factory
that produces cars. Which part of the factory is most similar to the nucleus of a
living cell?
A.
B.
C.
D.
a conveyor belt that transports materials.
a storage bin that holds the pieces needed to assemble a car.
the computer room that controls the assembly process. – sends out signals of what to do.
the generator that provides energy for the factory.
56. In which process is oxygen used to release the energy stored in food?
A.
B.
C.
D.
photosynthesis 6CO2 + 6 H2O + energy → 6C2 + C6H12O6 creates food
respiration 6O2 + C6H12O6 → 6H2O + 6CO2 + energy uses food to give off energy
digestion
reproduction
57. The fur of a snowshoe rabbit changes to white during the winter. This change is an example of:
A.
B.
C.
D.
adaptation
competition
metamorphosis
metabolism
Base your answers to the following questions on the diagram below. The diagram shows the offspring of a
white mouse and a gray mouse. All of the offspring are gray.
58. Which is a correct gene combination for the parents shown in the diagram?
A.
B.
C.
D.
GG X GG
gg X gg
gg X GG
Gg X Gg
59. If two gray (Gg) mice mated, what percent of their offspring would have pure white fur?
A.
B.
C.
D.
25%
50%
75%
100%
60. Competition is most likely to occur between which two organisms?
A.
B.
C.
D.
deer and butterflies
owls and bacteria
goldfish and rabbits
grass and strawberry plants
61. What is the result of cellular respiration?
A.
B.
C.
D.
Energy for cell processes is released. *In the form of ATP
Oxygen is released for photosynthesis.
Cells undergo decomposition.
Nutrients are excreted to prevent the buildup of body fat.
62. Living things are classified as producers or consumers according to:
A.
B.
C.
D.
their speed of movement
the size of their communities
how they obtain food
how they reproduce
The diagram shows a food web.
63. Which three organisms in the food web are competing for the same food resource?
A.
B.
C.
D.
carrot, rabbit, and fox
grain, bird, and owl
fox, owl, and rabbit
bird, mouse, and grasshopper - all eat grain for food.
64. Which statement would be true if the owl population disappeared?
A.
B.
C.
D.
The mouse population would increase. – without the predator eating it, the population would increase.
The carrot population would increase.
The fox population would decrease.
The rabbit population would decrease.
65. How do decomposers obtain their food?
A.
B.
C.
D.
hunting and killing prey for food
changing carbon dioxide and water into food
absorbing food from dead organisms
producing food from oxygen and sunlight
66. Which life process is shown by the equation below?
A. circulation
B. reproduction
C. locomotion
D. respiration
67. Which three systems of the human body function together to move and control body parts?
A.
B.
C.
D.
nervous, skeletal, and muscular
muscular, endocrine, and excretory
digestive, excretory, and reproductive
circulatory, endocrine, and respiratory
SHORT OPEN-ENDED QUESTIONS:
1. Some quantity of a solid reacts with 40 grams of a liquid. All of the reactants are used up in the
reaction. The final products are a compound with a mass of 72 grams and a gas with a mass of 8
grams.
Beaker A
Beaker B
Beaker C
A. What was the mass of the original solid (Beaker A) in the reaction? Show your work.
72g of compound in beaker C + 8g of gas given off of beaker C
72g + 8g = 80g of total mass for reaction of beakers A and B
Final mass = Reactant 1 + Reactant 2
Beaker C = Beaker A + Beaker B
80g = X + 40g
-40
-40
40g = X
The mass of the unknown solid in Beaker A is 40g.
B. Name one piece of evidence from the diagram that indicates a chemical change is taking
place.
The bubbles that are found above beaker C would indicate that a gas was created from the mixing of
the reactants in beakers A and B. The formation of a new substance gives evidence that the reactants
molecules were rearranged to form new bonds which produced a new phase of matter the gas.
2. A student is testing the rates at which sand and water heat up. He puts 1 kg. of sand in one
container and 1 kg of water in an identical container. He uses four thermometers: one near the
surface of the sand, one near the bottom of the sand, one near the surface of the water, and one
near the bottom of the water. He places an infrared lamp over each container. Every 10 minutes,
he records the temperatures measured by each thermometer. The table shows the data from the
experiment.
TEMPERATURES WITH LAMP ON
Time with Infrared
Lamp on (min)
Temperature at
Top of Sand (oC)
Temperature at
Temperature at
Temperature at
o
o
bottom of Sand ( C) Top of Water ( C) Bottom of Water (oC)
0
22o
22o
20o
20o
10
31o
26o
24o
21o
20
39o
32o
26o
23o
30
40o
34o
28o
25o
A. Make a conclusion that compares the rates at which sand and water heat up. Use data from the table
to support your conclusion.
Over the 30 minute period you can conclude that sand heats up faster than water. To support this you need to
compare the temperature at the top of sand to the temperature at the top of water and find the total temperature
increase for both. The final temperature reading for the top of the sand is 40 degrees and the start temp. was 22
degrees. You must then subtract 40 – 22 for a change of 18 degrees temperature change. For the final temp at
the top of the water you can do the same math 28 – 20 and you get an 8 degree temp change. For the temp. of
sand at the bottom and the temp. of water at the bottom. When you do the math 34 – 22 you get a 12 degree
temperature difference and for the bottom of water 25 – 20 you get an 5 degree difference. Your total
temperature change for sand 18 degrees and 12 degrees is greater when compared to the total temperature
change of water 8 degrees and 5 degrees respectively. (might be easier to do a chart here)
B. Identify two methods of heat transfer (conduction, convection, radiation) involved in this experiment.
Explain the role of each method in heating up the sand and water.
Radiation- Occurs when the infrared lamp heats the sand and water by a wave through empty space.
You can show evidence that this is happening because the temperature at the top of the sand and water
increases over the 30min period.
Conduction – Is the heat transfer by direct contact. Each sand molecule is being heated by radiation
at the top but because all of the molecules of sand are touching the heat gets passed from molecule to
molecule like when you play the game hot potato. The evidence to support conduction is that the temp for
the bottom of the beaker at the start is 22 degrees and by the end the temp is 34 degrees. Again the 12
degree gain in heat provides evidence that conduction is happening in the beaker.
Convection – Is the heat transfer for a fluid. Again the radiation is used to start heating the denser
colder molecules at the bottom of the beaker. Once these denser colder molecules gain a little bit of heat
they become less dense and start to rise. The changes in temperature and density force a circular motion as
heat is transferred. The evidence for this is looking at the temperature at both the top of the water 20
degrees and bottom 20 degrees at the start of the experiment. By the end of your experiment the top of the
water is 28 degrees and the bottom is 25 degrees. The difference is only 3 degrees but it is enough of a
temperature difference to allow a convection current to form.
3. Roller coasters are among the most popular amusement park rides. They are exhilarating and
thrilling to the people who ride them. How a roller coaster works is quite simple.
1. Almost all roller coasters start by going up a hill. The coaster is pulled up the hill by a
moving chain. A motor provides the energy for the moving chain. The energy from the
motor is transferred to the coaster.
2. At the top of the hill, the coaster has stored energy, or potential energy. It has the most
potential energy on the first hill. As the coaster goes over the top of the hill, the chain is
released and the coaster falls freely on the tracks.
3. As the coaster moves rapidly down the first hill, its potential energy changes into energy of
motion, or kinetic energy. It has kinetic energy because it is moving. This kinetic energy
carries it to the top of the next hill.
4. The kinetic energy is converted back into potential energy when the coaster reaches the top of
the second hill. As it goes down the second hill, the potential energy is again changed into
kinetic energy. This happens over and over on each hill until the coaster reaches the station
and is stopped by the coaster’s operator.
Note: Each hill of a roller coaster must be smaller than the one before it for the coaster to have
enough energy to make it over all of the hills. The coaster loses some of its energy between hills
because of track friction and air resistance.
Predict what would happen if the third hill on a roller coaster ride were bigger than the first hill.
Explain your answer.
If the third hill on a roller coaster ride were bigger than the first hill the cart would not make it over the third
hill. The cart would end up stuck between the second and third hill. It would end up being stuck because
the first hill would not have enough potential energy stored to convert into enough kinetic energy in order
for the cart to get over the third hill. (for every reaction there is an equal and opposite reaction but because
there is friction between the wheels of the cart and the track your first reaction must have a bit more energy
because energy is being lost throughout the ride potential energy always needs to be greater than kinetic
energy on a roller coaster)
4. A student goes skateboarding a few times a week. The student notices that she can go faster while
skating on some level surfaces than on others. She hypothesizes that speed has something to do with the
surface she is skating on. The student wants to design an experiment to test this hypothesis.
A. Identify the independent (manipulated) variable in the experiment.
*The independent variable is the type of surface that the girl is skateboarding on.
B. Identify the dependent (responding) variable in the experiment.
*The dependent variable is the speed at which the skateboard travels.
C. Identify two factors that will need to be held constant in the experiment.
1. Use the same skateboard and rider on each surface.
2. Use the same force / starting speed for each trial.
Base your answers to the following questions on the diagram below, which shows Earth
at one point in its orbit around the Sun. The length of daylight experienced at different
latitudes on a given date is shown on the diagram.
5.
Describe how the length of daylight changes from the Equator to the North Pole on
the date shown.
*As one moves from the equator to the North Pole, the length of daylight decreases.
6. What season is beginning in the Northern Hemisphere?
*The Northern Hemisphere is experiencing winter. (Tilted away from sun.)
Base your answers to the following questions on the diagram below. The diagram shows the relative
strengths of the gravitational force for planets of different masses. The size of each planet represents the
planet's relative mass. The arrow length indicates the relative amount of gravitational pull that each
planet would exert on an astronaut in space.
7. What is the relationship between the mass of the planets and the relative strength of their
gravitational pull?
*Larger, more massive planets, have stronger gravitational pulls.
8. Which three planets shown have less gravitational pull than Earth?
*Mercury, Mars, and Pluto have less gravitational pull than the Earth.
Base your answers to the following questions on the information and diagrams below.
Saltwater plants of the same species were grown in soil in separate containers with 1 liter of water. All of
the plants were the same height at the beginning of the experiment. Different amounts of salt were
dissolved in each container as shown in the diagrams. All other conditions were held constant.
Measurements for the final height of each plant are provided.
9. What is the control in this experiment?
*The tank of water with zero grams of salt would be the control.
10. State one conclusion, based on the information provided, about the growth of this type of saltwater
plant in water containing 0 to 20 grams of salt per liter.
*Higher concentrations of salt cause the saltwater plant to grow taller. In other words, the more salt in the
water, the taller the plant will grow. (Given the parameters of this investigation, the previous statement is
true. Who knows, if you add more than 20 grams of salt, things could change. The plant could die.)