th
7 Science
Exam Review Key 2015
USE THE INFORMATION IN THIS PACKET TO
CHECK YOUR ANSWERS. MAKE SURE YOU ALSO
ATTEND TUTORIALS, STUDY YOUR NOTES, TEST
REVIEWS, LABS, ETC.
EXAM SCHEDULE
Thursday – 5/28
4th & 5th Period Exams
Early Release @ 12:00
Wednesday - 5/27
1st, 2nd, & 3rd Period Exams
Regular Release @ 3:15
Friday – 5/29
6th & 8th Period Exams
Early Release @ 12:00
NO SECTIONS WILL BE ACCEPTED FOR “LATE CREDIT” AFTER 5/21.
THE KEY WILL BE POSTED ONLINE on Friday 5/22.
CHEMISTRY
1. Matter: any material substance with Mass & Volume
2. Physical Property: Can be observed using your senses (mass, color, shape, smell, volume, density, melting point,
boiling point, and hardness)
3. Chemical Property: Cannot be observed with senses- must be tested or reacted with something (ability to burn,
ability to decompose (food), ability to rust, how it reacts with other substances)
4. Physical Change: Do NOT CHANGE THE IDENTITY OF MATTER on a chemical level
a. Give 3 examples: change in state, shape, color, size
5. Chemical Change: Matter changes at the atomic level (atoms separate and recombine in different ways!)
and NEW SUBSTANCES are created
a. Give 3 examples: Rusting, Burning, Cooking
6. Signs of a chemical change: Formation of a gas, formation of a precipitate (solid), change in temperature,
change in color, energy produced
7. Law of Conservation of Mass/Matter: Matter cannot be created or destroyed, only transformed/changed
8. Atom: the smallest particle making up elements
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9. Element: pure substances that make up everything in the universe
10. Molecule: 2 or more elements chemically combined to form a new substance with new properties
11. Compound: 2 or more DIFFERENT elements chemically combined to form a new substance with new properties
a. Give an example of something that is a molecule, but not a compound: H2, O2, Au (gold)
b. Give an example of something that is a molecule and a compound: H2O, CO2
12. Pure Substance: Something made up of only one type of atom
13. Four Types of Organic Compounds:
a. Carbohydrates
b. Lipids
c. Proteins
d. Nucleic Acids (DNA & RNA)
*Also know how each main example is broken down by our bodies
*What element do all organic compounds contain? Carbon
14. Your digestive system must break down carbohydrates into Simple Sugars so your body can use them.
15. Acid: Something with a pH less than 7, sour, reacts with metals
16. Base: Something with a pH greater than 7, bitter, slippery
17. Neutral: Something with a pH of 7, does not react
18. pH: the measure of how acidic or basic a substance is
ECOLOGY 1
19. Biome- large geographic area that shares similar vegetation and climate (temp & precip)
*Know general characteristics of the world’s major biomes- see notes
*be familiar with structural/behavioral characteristics needed to survive in different biomes
20. Adaptation- a body structure or behavior that helps an organism survive
21. Structural Adaptation- physical characteristics that help an organism survive
22. Behavioral Adaptation- a behavior or activity that helps an organism survive
23. Instinct- a pattern of behavior that requires no thinking- organisms know how to do this from birth
24. Migration- an instinctive behavior where some animal populations more to a new place for a period of time
25. Hibernation- an instinctive behavior where some animals spend winter in an inactive condition
26. Learned behavior- a behavior that an animal learns through experience
27. Mimicry- an adaptation where one species mimics another species (in looks or behaviors)
28. Camouflage- an adaptation where an organism can blend in with its surroundings
29. Natural Selection-gradual process where populations naturally change over time; some traits become more
common and other traits become less common
30. Selective Breeding- humans select specific traits to breed together to get a certain outcome
31. A bird is born with a beak that is longer than the beak of other birds in the species. The
longer beak helps the bird catch more food, which makes it healthier than the other birds, this will live longer
and breed more than the other birds. Is this an example of natural selection, or selective breeding?
This is natural selection, because the trait is beneficial it is more likely that the bird will survive. Because it
is more likely to survive, it is more likely that its genes will get passed on and that trait may become more
common. It’s natural selection because there is NO human involvement.
32. A pet store is breeding two different types of dogs, hoping they will produce a combination of both of the
dogs traits in their offspring. Is this an example of natural selection, or selective breeding?
This is selective breeding, because humans are controlling the breeding so that certain traits occur in the
offspring. It’s not a natural process.
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33. Biotic - a living factor in an ecosystem
34. Abiotic - a non-living factor in an ecosystem
35. Symbiosis – a close relationship between 2 species (“symbiosis”= living together)
a. Parasitism: (+/-) one organism benefits while the other organism (host) is harmed
b. Mutualism: (+/+) both organisms benefit in this relationship
c. Commensalism: (+/0) one organisms benefits, and the other organism isn’t hurt or helped
36. Limiting factor - any factor that restricts the size of a population (space, resources, mates, natural disasters,
disease, hunting, etc)
37. Competition - organisms attempting to use the same resource at the same time
38. Predation – one organism (consumer) captures and kills another organism (consumer) (this is NOT a type of
symbiosis!)
39. Niche – an organism’s specific role or job within its ecosystem that helps it survive
40. Habitat – where an organism lives within its ecosystem
41. Species – organisms of the same kind that can interbreed
42. Population – organisms of the same species
43. Community – all of the populations in an ecosystem
ECOLOGY 2
44. Stimulus- something that causes a response
45. Response- a reaction brought about by a stimulus
46. Internal Stimulus- stimulus that comes from inside the animal
47. External Stimulus- stimulus that comes from outside the animal
48. Phototropism- a plant’s growth in response to light
49. Geotropism- response to earth's gravity, as in the growing of roots downward in the ground
50. Producer - an organism that makes its own food (also known as autotroph)
51. Decomposer - organism that breaks down and obtains energy from dead organic matter
52. Consumer - an organism that obtains energy by feeding on other organisms (also known as heterotroph)
53. Biomagnification – the process where toxins increase in concentration as they move up the food chain
54. Give 2 examples each of internal and external stimulus & response:
Internal: hunger- eating; thirst- drinking External: light- squint; temperature- put on jacket
55. Explain the difference between the terms autotroph and heterotroph.
An autotroph is capable of making its own food/energy (a producer) while a heterotrophy has to go and
consume food for energy (a consumer).
56. Use the key on the right to identify the organisms below.
Common Name
Scientific Name
1. dog
Canis familiaris
2. shark
Carcharodon carcharias
3. rose
Rosa sylvestris
4. skunk
Mephitis mephitis
5. turkey
Meleagris gallopavo
6. dolphin
Tursiops truncates
7. eagle
Haliaeetus leucocephalus
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57. Diagram a simple food chain (using any organisms) and label the following parts; producer, primary
consumer, secondary consumer, tertiary consumer, and quaternary consumer.
Sun
Producer

Primary C

Secondary C

Tertiary C.

Quaternary C

58. What do the arrows in a food chain represent? Explain why the arrows on food chain point in a specific
direction.
The arrows of a food chain indicate the direction in which the energy flows.
59. Describe the 10% rule and how it applies to food chains. Also, explain what happens to the other 90% of
the available energy.
The 10% rule describes how much energy is transferred to each organisms in the food chain/web/pyramid.
When a consumer eats the previous organism, it will use 90% of the energy for itself while 10% will be stored
and available for the next consumer in line.
60. Using your food chain from #57, design and solve one 10% rule problem for your food web.
Sun

100,000j
Producer
Primary C

10,000j
Secondary C

1,000j
Tertiary C.

100j
Quaternary C

10j
1j
61. Write out the chemical equation for photosynthesis.
6CO2 + 6H2O + sunlight  6O2 + C6H12O6
Carbon dioxide + water + sunlight  oxygen and glucose
62. What types of organisms can photosynthesize?
Plants (autotrophs) because they have chloroplasts with chlorophyll.
63. What type of energy transformation occurs during photosynthesis?
Solar energy from the sun is transformed in to potential energy (glucose).
64. In the above food web, identify a:
Producer:
pond grass
Primary Consumer:
grasshopper
Secondary Consumer:
duck
Tertiary Consumer:
owl/hawk
65. What organisms would potentially suffer if the grasshopper population greatly decreased due to harmful
pesticides? How might this change impact the overall food web?
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The populations of songbirds, ducks, mice, and shrews would greatly decrease. The shrews would decrease
the most because they do not have any other source of energy besides the grasshoppers. If the shrews
eventually die off, it would reduce the variety of energy sources for the hawk/owls and that in turn would
throw off all biodiversity making the ecosystem much weaker and less likely to sustain itself.
66. What do the arrows represent (in a food chain/web)?
The transfer of energy from one organism to another along the food chain.
67. At which level in a food chain/web is there the greatest amount of available energy?
Producer will have the greatest amount of energy.
68. Explain the difference between a food web and a food chain.
•
Food webs are a simple transfer model of energy from sun to producer to primary consumer to secondary
consumer to tertiary consumer.
•
Food chains are interconnected food chains
69. If you ate 3 big fish, which had each eaten 5 small fish, who had each had 10 insects, who had each had 25
plant pieces, how much methylmercury would be in you? Assume that each plant piece each has one drop of
methylmercury.
3750 drops of methylmercury
ENVIRONMENTAL CHANGES
70. Weathering- the chemical and physical breakdown of rock
71. Erosion- the movement of sediment, or weathered rock, from one place to another
70. Deposition- the placement of weather rock, or sediment, at a site other than its place of origin
71. Condensation-process where water vapor collects in clouds (as the clouds cool the water vapor condenses
into water drops).
72. Precipitation- water falls to the earth from clouds- mainly as rain, but sometimes as snow, sleet or hail.
73. Transpiration- the process by which plants lose water out of their leaves
74. Evaporation- the process where heat energy from the sun causes bodies of water (puddles, lakes, rivers
etc.) to change from liquid to a water vapor; vapor then rises into the air and collects in clouds.
75. Watershed- an area of land from which all runoff drains/”sheds” to the same body of water.
76. Aquifer- a layer of underground rock, or sediment, through which water can move easily.
77. Runoff- water travels downhill and enters into rivers and lakes
78. Water Table- the underground depth at which point the ground is totally saturated with water.
79. Ground Water- flows underground as spring or underground rivers (stored in aquifer).
80. Surface Water-water on the surface of the earth.
83. Describe the steps of ecological succession. Use the words climax community, pioneer species, and
biodiversity in your explanation. Ecological succession is a series of predictable changes that occur in a
terrestrial community over time. In a place where soil is not present, primary succession would begin once
the first organisms, or pioneer species, such as lichens arrive. Lichens do not need soil to live and would
be able to thrive. As lichens decompose they add to the soil, which was created by rocks being broken
down by weathering and erosion. Simple plants are able to live and grow in the soil, and soon more
complex organisms and animals are able to survive leading to a climax community. This climax or stable
community completes the process of succession; biodiversity has been achieved and a great variety of
different organisms will remain and exist together, as long as the community is undisturbed.
84. What is the difference between primary and secondary succession?
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The difference between the two types of succession is the presence of soil in the area where the process
will occur. Primary succession usually occurs in a place without soil (typically after a natural disaster),
such as volcanoes landslides or floods. Primary succession is much slower because soil has to be
created.Secondary succession usually occurs in an area where soil already exists. “Step 1” of primary
succession is skipped and occurs much faster.
85. Explain the process of eutrophication.
Eutrophication is the process where an aquatic ecosystem becomes rich in nutrients. Sediments and
decomposing organisms slowly build up on the bottom of the bodies of water, and eventually the water
disappears and the area becomes land.
86. What are the 3 “R’s” of conservation?
Reduce, Reuse, Recycle
87. What are fossil fuels? Describe how they are formed; and list the 3 types.
Fossil fuels are non-renewable natural resources; they cannot be replenished, re-made or re-grown in a
short period of time (think about fossils). They’re formed over a long period of time, as plants and animal
remains are buried. Over time, the heat and pressure causes them to turn into coal, oil and gas. Examples:
coal, petroleum and natural gas.
88. Explain the differences between renewable and nonrenewable resources. List 2 examples of each.
The difference between these natural resources is the time it takes to replenish, or make more of them.
Non-renewable resources cannot be replenished (nuclear, fossil fuels: coal, petroleum, natural gas), while
renewable resources (soloar, geothermal, wind, biomass, and water) can be replenished in a short time
period. Inexhaustible resources are renewable resources that will not be used up (or, “exhausted”) because
they exist in great abundance.
89. Why do humans continue to use nonrenewable resources, if they’re so bad for the environment? Think of
2 reasons.
Humans may continue to use nonrenewable resources because renewable resources are costly to
implement (building the infrastructures needed to use them), and the amount of energy that is produced by
these resources is not as great, when compared to nonrenewable resources.
90. Give 3 examples how humans negatively impact the world around us- including the watersheds and
ecosystems. Be specific. Answers will vary, but could include the following reasons.
1. Overpopulation and urbanization can lead to overuse of natural resources and water.
2. Deforestation, removal of trees for buildings and resources, thus removing the habitats of various
organisms.
3. Pollution, emitted from the use of natural resources and/or many other causes, can lead to water and air
pollution. These causes can lead to a change in the ecosystems the overuse of the resources can lead to air
pollution, harming humans, as well as organisms and their habitats.
91. What is an anthropogenic change? Anthropogenic changes are those that are caused by a human
(“anthropo” means human).
92. List the 5 most common anthropogenic changes.
1. Overpopulation
2. Urbanization
3. Habitat Destruction
4. Overuse of Natural Resources
5. Pollution
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PHYSICS & ASTRONOMY
93. Define work: work is done when a force causes an object to move in the same direction the force was
applied
94. What is the formula for work? Work = Force x Distance
95. List the units for work, force, and distance. Work – Joules, Force – Newtons, Distance – Meters
96. What are the 3 ways that simple machines help us?
1. They can change the amount of force required
2. They can change the distance the object has to move
3. They can change the direction (allowing you to work WITH gravity rather than against it)
97. Name the 4 types of simple machines discussed in class, sketch one real life example, and explain how we
use them to make work easier to accomplish.
Name:
Lever
Sketch:
Name:
Pulley
Explain:
Reduces the force
required
Name:
Wheel and Axle
Sketch:
Explain:
Changes direction or amount of
force required
Sketch:
Name:
Inclined Plane
Sketch:
Explain:
Increases distance, but
Explain:
Increases force, but distance is decreased
reduces the force required
98. What is an advantage of using simple machines to help you do work?
They make work seem easier!
99. What is the general disadvantage of using simple machines to help you complete work?
It takes longer to set up/use.
100. Write the equation for calculating the Mechanical Advantage of a ramp: MA = slope/height
Use the following diagrams of inclined planes to answer questions 101-102.
Plane 1
1m
Plane 2
5m
9m
3m
101. Which inclined plane has the HIGHEST mechanical advantage? Plane 3
102. Which inclined plane has a mechanical advantage of 3? Plane 2
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Plane 3
3m
45 m
Practice Problems- Remember to SHOW WORK and include CORRECT UNITS!
103. How much force would be required to push a chair 22 m down the hall, doing a total of 88J of work?
W= F x D
88J = F x 22m
F = 4N
104. What is the height of the table if the inclined plane has a mechanical advantage of 4 and the length of the
slope is 24 m?
MA= slope/height
4 = 24m/h
h = 6m
105. If a ramp has a mechanical advantage of 9, and it is 36 meters long, how high is it off of the ground?
MA= slope/height
9 = 36m/h
h = 4m
106. It will take 400 N of force for Mrs. McCormick’s students to lift a piano 4 meters up onto the stage.
Luckily, Madeline suggests they use an inclined plane to make their job easier. If the inclined plane is 8
meters long, how much force will the students need to use to push the piano up on the stage? *Must include
correct units!!*
W= F x D
W = 400N x 4m
W = 1600J
1600J = F x 8m
F = 200N
107. What is energy? Energy is the ability to do work
108. Describe the difference between potential and kinetic energy.
Potential Energy




Kinetic Energy


Stored energy due to an object’s position
Amount of potential energy depends on
height and mass of an object
Higher elevation (height) = more potential
energy
More massive objects = more potential
energy


Energy of motion
Amount of kinetic energy depends on speed
and mass of an object
More speed an object has = more kinetic
energy it has
More massive objects = more kinetic energy
109. What is an energy transformation? Give two examples.
An energy transformation is when one form of energy changes or converts to another form. For example, our
bodies turn food into chemical energy. When we use our muscles, the chemical energy from our food gets
converted into mechanical energy. Another example might be a battery powered flashlight. The battery
inside the flashlight has chemical energy which gets converted to electrical energy to turn the flashlight on.
The electrical energy then gets converted to light energy that we see and thermal energy that we can feel.
110. List at least 5 different forms of energy, and an example of each:
Form of Energy
Example
Thermal
Sound
Mechanical
Electrical
heat lamp
bell, tuning fork
using a hammer
light bulb, electric (hybrid)
car
battery acid, fossil fuels,
food
stretched rubber band
lamp, stars
Chemical
Stored mechanical
Light
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Solar
sun, solar powered
calculator
nuclear bomb, nuclear
power plant
volcanic eruptions, geysers
Nuclear
Geothermal
111. What does the Law of Conservation of Energy state? Energy cannot be created or destroyed; it simply
changes form.
112. List all 7 fundamental traits of living things:
1. Made of cell(s)
2. Has DNA
3. Able to reproduce
4. Grow & develop
5. Obtain & use energy
6. Respond to stimuli
7. Maintain homeostasis
113.What are the 4 qualities of Earth that enable it to sustain life?
a. Distance from the sun
c. Presence of water
b. Earth’s unique atmosphere
d. Gravitational pull
114.How is human life sustained by the sun? The sun fuels all life processes – all organisms get their energy
from the sun somehow.
115.What are the 4 spheres that make up the Earth?
a. Lithosphere – Earth’s crust (soil, rocks, minerals)
b. Hydrosphere – Earth’s water
c. Atmosphere – the gases in the air
d. Biosphere – all living things
116.What gases make up our Earth’s atmosphere? Nitrogen, Oxygen, and Argon remain constants in our
atmosphere while there are varying trace amounts of CO2 and water vapor
117.What are the 2 most important functions of our Earth’s atmosphere?
1. Greenhouse Effect – the gases in the atmosphere absorb heat emitted by the sun which warms the
atmosphere
2. Protection – protects us from meteors
118.What is the difference between mass and weight? Mass is the size of an object and weight is the amount
of force gravity has on an object
119.How is the mass of a planet related to the amount of gravity on a planet? Objects with more mass have
more gravity.
120.Why is water such an important resource to us on Earth? It is crucial in photosynthesis and without
photosynthesis we would not have oxygen and could not sustain life on Earth.
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