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8th Grade Science 4th 9 Weeks Test Review
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last test of
the year!
Energy in Ecosystems:
1. Darwin’s 5 Observations regarding Natural Selection are:
1. Survival of the fittest – Organisms best ___adapted______________ to the
environment will most likely ___survive__________________.
2. Reproduction – Organisms that survive will ____reproduce_________________.
3. Heredity – Genetic traits are passed on from ___parents_______________ to
___offspring________________.
4. Overproduction – This occurs when more offspring is
__produced___________________ than can ___survive_________________.
5. Competition – All organisms __compete________________ for resources.
2. The Galloway Rabbit has an all black coat. About 10% of these rabbits have been
born with a white coat. If the natural habitat for the Galloway Rabbit changes from a
dark forest to a snow covered forest, what will we see happen in the population? _
The white rabbits will be better for the new environment and will be more likely to survive, therefore the
population will begin to have a majority of rabbits with a white coat over time.
3. Give an example of a predator/prey relationship from the following organisms:
(Auburn) Tiger
Gazelle
Grass
Fungi
Flowers
____The tiger is the predator and the gazelle is the prey. _________________
4. What is an abiotic energy source that must provide energy to all organisms? ____sun_______________
5. Label the energy pyramid with the different energy levels we have learned. Give an
example of each and put how much energy
1
is transferred at each level.
10
100
1000_
Everybody
loves an A!
8th Grade Science 4th 9 Weeks Test Review
6. Name, define, and give an example of the three types of symbiotic relationships:
1. __ Mutualism: Both organisms benefit from the relationship. Ex- A bee gets nectar from a flower and
the flower receives pollen carried by the bee.
2. Commensalism: One organism benefits and the other is unaffected. Ex – A bird benefits from nesting in
a tree and the tree is unaffected.______________________________
3. Parasitism: One organism benefits and the other is harmed. Ex- A flea benefits from feeding off the
blood of a dog and the dog is harmed by the relationship._____________________________
7. In a parasitic relationship, what can we call the organism that is being fed off of? __host____________
8. What role in the energy pyramid breaks down dead organisms?
a. producers
b. consumers
c. decomposers
9. If a mutualistic (+ +) symbiotic relationship is meant to help both species thrive, what do you think will
occur with both species’ populations as time goes on?__ Their population will increase. Remember that
with mutualism, they survive better together than they do apart.
10. What does abiotic mean? ___nonliving___________________________________________________
11. What does biotic mean? _____living_____________________________________________________
12. If an asteroid hit the planet, what would be the implications for ecosystems on Earth? Give reasons
for your answer.__ Dust could spread in the atmosphere, causing wide scale climate change and the death
or organisms unequipped to handle to massive change to their environment.
13. Draw a food chain with at least 5 organisms. What do all food chains start with? The sun
Plate Tectonics and Continental Drift:
1. Where do we usually find faults and volcanoes? ____Where two plate boundaries meet___________
______________________________________________________________________________________
2. If the continents were at one time joined together as Pangaea, what might we expect to see around our
coastlines that were at one point joined together? (Hint: pieces of evidence)______________________
__Similar shaped coastlines, landforms that line-up, similar fossils and minerals on different continents
3. The collisions of a mountain plate result in what two mountain features found in rocks?
__Collision causes the folding and faulting of rock which we see in our current mountains
4. Define the Theory of Plate Tectonics. _The Earth’s crust is cracked and made up of many plates that are
constantly moving. Convection currents in the mantle create enough heat and pressure to cause these
plates to move. __
8th Grade Science 4th 9 Weeks Test Review
5. What is the area called where new ocean crust is formed? What type of boundary is this? Why doesn’t
the earth’s crust keep getting bigger? __Rift valleys are formed when divergent plates move away from
each other. As new crust is formed in the rift valleys, older crust melts back down into the mantle at
subduction zones.
6. Draw and label the three types of plate boundaries. Use arrows to indicate how they move.
Convergent: plates move toward each other → ← (creates mountains, trenches, volcanoes)
Divergent: plates move away from each other ← → (creates rift valleys and ridges)
Transform: plates move past each other ↑ ↓ (creates earthquakes and fault lines)
7. What theory has helped us explain how earthquakes happen? What is actually causing them to occur?
__The Theory of Plate Tectonics. Friction builds up, and eventually causes the faults to slip past each other.
8. What happens during subduction? (Draw a picture to go along with it.)
At this convergent boundary one plate is pushed under the other and begins to remelt back into the
mantle.
9. Describe the movement of convection currents. Where are they located within the earth? _________
_The movement of convection currents causes the Earth’s plates to move. As the magma is heated, it rises
to the top of the mantle (where they are located), where they cool and begin to fall. Located in the mantle.
10. At the mid-ocean ridge Peekapoo, magma constantly coming to the surface due to the divergent
boundary. Where would the newest, and therefore youngest, crust be in this scenario? _The newest crust
is formed in the rift valleys.
11. As we go deeper into the earth, what happens to the temperature and pressure? __The temperature
increases as we go deeper into the earth. (So does pressure!)
Rock Cycle, Weathering, Erosion, and Deposition:
1. Define weathering. ___The breaking down of rock by chemical or mechanical means
2. Describe how erosion and deposition shape the land. ___Erosion is the movement of rock and
sediment and deposition is the “depositing”, or placing, of this sediment in a new location.
_____________________________________
8th Grade Science 4th 9 Weeks Test Review
Weather:
Weather fronts push across the USA in a _west____to__east______ direction. Fronts are always
attached to _low_______ pressures. Clouds and storms build up at fronts because cold air and warm air
come in contact which makes the water vapor in the warm air _rise and condense____. The greater the
temperature difference between the air masses, the more _violent____ the storms become.
Why does cold air sink and warm air rise? (don’t tell me b/c one is heavier than the other!) __ Cold air is
more dense so it sinks below the warm air that is less dense.
Define Convection and give an example: __Heat transfer of a fluid when the heated fluid is moved away
from the heat source, taking energy with it. Example: heat coming off of a fire to warm
marshmallows.__________________________________________________________________________
Define Radiation and give an example: _Energy that comes from a source and travels through some
material or space. Example: warm air coming through a hair dryer to dry your hair.
What kind of weather comes with a:
Cold front: __cold, strong storms, colder temps after
Warm front: __warm, humid, light rain, warmer temps after
Stationary Front: __overcast, gloomy for days
Occluded Front: __light rain or other precipitation, fair, cooler weather
What weather comes with the following?
High Pressure __clear, sunny, “happy” weather
Low Pressure __storms, rain, clouds, wind, “yucky” weather
Lunar Cycle, Tides, Seasons, and Light Years:
It takes __29.5______ days for the moon to revolve around the _earth_______, giving us the
lunar cycle and moon phases.
Neap Tide
Spring Tide
Spring Tide
Neap Tide
8th Grade Science 4th 9 Weeks Test Review
Light Years are a measure of distance in space based on __how far light travels in 1 year
If you turned on a HUGE spotlight and pointed it out into space, when would an alien
see the spotlight if they were on a planet 300 light years away? _300 years
Why do we use light years instead of km to measure the distance to stars?_kilometers
are too small to make sense to use
Label the four seasons on the diagram below:
Northern – Spring
Southern - Fall
Northern – Summer
Southern - Winter
Northern – Winter
Southern - Summer
Northern – Fall
Southern - Spring
In the diagram above, at the Earth’s position at the arrow, what season is it in the
northern hemisphere? __summer_________________________
What season is it in the southern hemisphere? __winter_____________________
What hemisphere is getting the majority of the sun’s rays? __northern______________
Why does that matter for the seasons? __The more directly the sun’s rays hit the earth’s
surface, the warmer the hemisphere will be._
What causes the seasons?__The tilt of the earth on its axis and its revolution
What season has the most hours of daylight? __summer__________________________
What season has the least hours of daylight? __winter____________________________
What two seasons have days and nights of a similar length? Why? __spring and fall.
Because the earth is not tilted toward or away from the sun during these seasons.
Physics:
1. What is the formula you use to find the speed of an object? speed=distance/time
2. What is the difference between speed and velocity?
Speed is a measure of how fast an object is moving and velocity is the same except it takes in
to consideration a certain direction the object is moving.
3. An object is in __motion______ when its distance from another object is changing.
4. What is Newton’s First Law of Motion? Give a real world example
Things at rest stay at rest, things in motion stay in motion, unless acted upon by an outside
force. Ex. When a car stops at a light, you stop also because you are
wearing your seat
belt.
8th Grade Science 4th 9 Weeks Test Review
5 What is Newton’s Second Law of Motion? Give a real world example
Acceleration of an object depends on its mass and the size of the force acting on the object. F
= m x a Ex. The dump truck takes longer to stop at a light than the little sports car.
6. What is Newton’s Third Law of Motion? Give a real world exampleFor every action, there is
an equal and opposite reaction. Ex. A bird flys higher in
the sky as its wings flap.
7. Match up the following using the appropriate number. 1. Newton’s first law of motion. 2.
Newton’s second law of motion, 3. Newton’s third law of motion
A_1 or 3_ A table rests on the floor.
B___1___ You are riding in a car which turns a corner really fast. You feel your
body sliding across the seat and into the door.
C___2____ The acceleration of a car is 2.0m/s²
D___3____ A rocket headed for Mars blasts off from earth.
E___1____ Wiley Coyote, who is dropped from the auditorium balcony, comes to a
sudden stop when he hits the floor below.
F___3____ Letting go of an inflated balloon whose end is not knotted.
G___1____ The motion of the rollercoaster at Valley Fair.
H___2____ The golf ball hit by the professional goes further than the one hit by the
amateur ( less experienced) golfer.
I____1___ You are driving your car and rear end another car. The person sitting in
the seat behind you is not wearing a seat belt and they bump the front of
their head into the back of your head.
Calculating; Solve the following using the appropriate formula (use triangles) and
units.
1.
s=d/t s= ?
2.
F= m x a
F= 30 N
d= 260 mi
F= ?
t= 4 hr
m= 10 kg
s= 260 mi/ 4 hr
a= 3 m/s²
s= 65 mph
F= 10 kg x 3 m/s²
8th Grade Science 4th 9 Weeks Test Review
Chemistry:
Fill out the following chart:
Particle
Location
Charge
Mass?
Proton
Nucleus
Positive- +
Yes- 1 AMU
Neutron
Nucleus
Neutral- 0
Yes- 1 AMU
Electron
Electron Cloud
Negative -
not enough to
measure
The Atom:
Label the parts proton, neutron, electron, nucleus, electron cloud on the atom diagram
below.
Electron
-
Proton
Elect
ron Cloud
Nucleus
+
+
+
+
+
Neutron
Draw and label 3 pictures of molecules in their different forms (solid, liquid, and gas).
Balancing Chemical Equations:
2 Fe
+ 1S

1Fe₂S
8th Grade Science 4th 9 Weeks Test Review
6Fe
+
Fe=
S=
2Cu
3S
6
3
+
S
Cu= 2
S= 1

3Fe₂S (Simplify- divide by 3)
Fe=
6
S=
3
Is this equation balanced? _no____
If not, balance it.

Cu₂S
Cu = 2
S= 1
Is this equation balanced? __yes__
If not, balance it.
Using Periodic Table:
What is the atomic number of cobalt? __27_______
What is the atomic mass of iodine? __126.904______
What is the symbol for molybdenum? ____Mo______
Measurement Skills:
In the space provided, write the instrument you would use to measure each item.
______ruler_______________ 1. The thickness of a coin
______thermometer_________ 2. The water temperature of an aquarium
______car_________________ 3. The distance between your home and your school
tape measure or measuring wheel 4. The area of a football field
______triple beam balance____ 5. The mass of a small insect
_____large graduated cylinder_ 6. The amount of gasoline needed to fill the gas tank
______stopwatch___________ 7. The length of time it takes you to walk a distance of one
meter
______triple beam balance____ 8. The mass of a small rock
_______ruler_______________ 9. The volume of a shoe box
_______stopwatch__________ 10. The amount of time in a class period
_______tape measure________ 11. The length of your bedroom
_______graduated cylinder____ 12. The amount of juice that can be placed in a small glass
8th Grade Science 4th 9 Weeks Test Review
_______large scale__________ 13. The mass of an automobile
tape measure or measuring wheel 14. The volume of concrete in a building
______thermometer_________ 15. Air temperature
density = mass/volume – mass – triple beam balance, volume – graduated cynlinder 16. Density of a solid
_______graduated cylinder____ 17. Volume of an irregularly shaped object