Name: 
 

2011 7th grade Science Midterm



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

Scientists conduct multiple trials of their experiments because ____.
a.
their results are more likely to be reliable
b.
it costs less to run more trials than fewer trials
c.
unusual occurrences are likely to be repeated every time
d.
experiments always have the same results
 

 2. 

Scientific ____ must be supported by observations and results from many investigations and are not absolute.
a.
constants
c.
systems
b.
theories
d.
laws
 

 3. 

A biology class in Louisville conducted a survey of the plant species found on their school grounds. They found several plants that they didn’t recognize. What resources would be most helpful to the class in identifying the plants and determining if they were introduced as exotic species?
a.
Kentucky newspapers and science journals
b.
Fossil records and historical society publications
c.
Biology textbooks and the encyclopedia
d.
Kentucky native plant checklists and plant identification keys
 

 4. 

In 1869, DNA was discovered within the nuclei of cells. By the 1940s, scientists knew that chromosomes were made of both DNA and protein but did not know which was the genetic material of cells. In the 1950s, scientists demonstrated that DNA is the material responsible for heredity.  In 1953, using information collected by other scientists, an American biologist and an English physicist built a three-dimensional model of DNA. These discoveries best illustrate the importance of —
a.
replication of results
b.
recent improvements in the scientific method
c.
collaborative efforts among scientists provided by reporting results
d.
independent research
 

 5. 

Richard was observing black swallowtail butterflies in the field. Which one of these is an observation he made about a black swallowtail butterfly?
a.
A black swallowtail belongs to the class Insecta.
b.
The black swallowtail is closely related to the spicebuch swallowtail.
c.
The black swallowtail laids its eggs on a parsley plant
d.
The black swallowtail likes to fly more than anything else. 
 

 6. 

Which of the following is most correct:
a.
You can accept or reject a hypothesis, but never prove it to be true.
b.
You can prove a hypothesis to be true.
c.
You can prove a hypothesis to be false.
d.
Accepting or rejecting a hypothesis is the same as proving whether or not the hypothesis is true.
 

 7. 

The major importance of Francesco Redi’s expermiment in 1668 is
a.
he proved idea of spontaneous generation.
b.
he performed the first real science experiment using the scientific method.
c.
he used his findings to improve medical practices.
d.
he was the first person allowed to perform an experiment in a butcher shop.
 

 8. 

Which statement below is most accurate?
a.
Observations involve most of the senses.
b.
Conclusions must always prove your hypothesis in order for your experiment to be considered a success.
c.
Laws are constantly changing due to results of scientific inquiries.
d.
Testing of a hypothesis is only done in a laboratory setting.
 
 
Joseph is performing an experiment to determine the affect of different types of fertilizer on the corn plants in his father’s garden.  His father has never used a fertilizer before and is curious to see how his yield changes if he tries one.  Joseph buys four different brands of fertilizer and plants four different rows of the same corn, using a different fertilizer for each row.  He then charts the growth of each row and corn production of each row during the summer.
 

 9. 

In Joseph’s experiment, the growth and corn production would be considered the
a.
independent variable
c.
experimental group
b.
control group
d.
dependent variable
 

 10. 

Joseph’s teacher informs him that he doesn’t have a control group and would need to add one in order for his experiment to be valid.  Joseph should have had which of the following as his control?
a.
corn planted with no fertilizer
b.
corn planted in a mixture of all fertilizers
c.
corn planted in composted soil
d.
corn irrigated one row of corn regularly to ensure plenty of water.
 

 11. 

The presence of the same ____ on several continents supports the hypothesis of continental drift.
a.
fossils
c.
neither a nor b
b.
rocks
d.
both a and b
 

 12. 

Matching ____ on different continents are evidence for continental drift.
a.
rock structures
c.
river systems
b.
wind systems
d.
weather patterns
 

 13. 

In the process of convection, hot material in the asthenosphere rises while cooler material near the surface of this layer sinks. When the warmer material cools, it becomes denser and begins to sink back down. How does the process of convection affect the asthenosphere?
a.
It causes the asthenosphere to sink, creating basins on which oceans sit.
b.
It does not really affect the asthenosphere in any way.
c.
It causes the lithosphere to bubble up and evaporate.
d.
It causes the asthenosphere to move and push against the pieces of the lithosphere.
 

 14. 

The youngest rocks on the ocean floor are located ____.
a.
at mid-ocean ridges
c.
near Asia
b.
near continents
d.
far from mid-ocean ridges
 

 15. 

The crust and upper mantle make up Earth's ____.
a.
asthenosphere
c.
continents
b.
lithosphere
d.
core
 

 16. 

Plates of the lithosphere float on the ____.
a.
atmosphere
c.
asthenosphere
b.
crust
d.
core
 

 17. 

Which of the following is true about the lithospheric plates?
a.
they move annually
b.
they never move
c.
they constantly move
d.
they move occasionally
 

 18. 

A type of earth change that is not caused directly by convection currents would be
a.
seafloor spreading
c.
volcanic activity
b.
continental drift
d.
erosion
 
 
nar002-1.jpg
 

 19. 

According to Figure 7-1, what type of plate boundary occurs between the North American Plate and the Eurasian Plate?
a.
divergent boundary
b.
transform boundary
c.
convergent oceanic-continental plate boundary
d.
convergent oceanic-oceanic plate boundary
 

 20. 

The hypothesis for the extinction of the dinosaur that has the most supported evidence is
a.
continental drift
c.
volcanism
b.
asteroid impact
d.
mammal competition
 

 21. 

Which contributes most to creating low tides?
a.
weak winds
c.
gravity
b.
water density
d.
water evaporation
 

 22. 

____ is a force that attracts all objects toward each other.
a.
Mass
c.
Distance
b.
Density
d.
Gravity
 
 
nar003-1.jpg
 

 23. 

Which point in the diagram below shows the position of a lunar eclipse?
a.
A
c.
D
b.
C
d.
B
 

 24. 

Which point in the diagram above could produce a solar eclipse?
a.
C
c.
A
b.
B
d.
D
 

 25. 

Seasons are a result of ______.
a.
Earth’s tilted axis and revolution
c.
Earth’s revolution
b.
Earth’s rotation
d.
Earth’s tilted axis and rotation
 

 26. 

Which statement about winter is true?
a.
The nights are short.
c.
The slanted rays of the Sun are weak.
b.
The days are long.
d.
The part of Earth that is in winter is tilted toward the Sun.
 

 27. 

Astronauts are much lighter when they walk on the Moon than when they walk on Earth.  This is because of
a.
the solar winds
c.
the light coming from the Sun
b.
the strength of the Moon’s gravity
d.
the depth of the Moon’s craters
 

 28. 

During spring tides, high tides are higher than normal and low tides are lower than normal.  What is the most likely cause of spring tides?
a.
an increase in the ocean’s salinity
c.
the Sun, Earth, and Moon forming a right angle
b.
the Sun, Earth, and Moon lining up
d.
an increase in wind speed
 

 29. 

The further away objects are from each other, the _________ the pull of gravity
a.
longer
c.
shorter
b.
stronger
d.
weaker
 

 30. 

The gravitational pull of the Moon has a greater effect than the pull of the Sun on the tidal changes in Earth’s ocean.  The most likely reason for this is
a.
Earth is larger than the Moon
c.
the Moon is closer to Earth
b.
the Sun is closer to Earth
d.
the Sun is larger than the Moon
 

 31. 

An astronaut is standing on the deck of a spacecraft which is orbiting Earth. He throws a moon rock sample towards outer space (where there is no friction). How much force is needed to keep the rock moving?
a.
No force is needed
c.
Double the original force
b.
The same as the original force
d.
One half the original force
 

 32. 

John accidentally left his books on top of his mom’s car before they left for school. The books stayed on top of his car while they were driving north on Oak Avenue. Then, when they made a sharp turn eastward onto Harris Lane, his books fell off the top of his car and onto the street.
a.
The people that live on Harris Lane hate reading, which caused the books to fall.
b.
The Earth's magnetic field held the books on John's car while he headed north. When he turned east, the magnetic pull faded, causing the books to fall.
c.
When John's car turned eastward, his books continued heading northward, causing them to slide off the top of his car and fall.
d.
The force of gravity caused John's books to slide across the top of his car and fall.
 

 33. 

A ball is thrown straight up in the air. According to Newton's first law of motion, what is the reason for the ball falling back to Earth?
a.
It is accelerating in the same direction as Earth's gravitational force on it.
b.
The change in the ball's acceleration is proportional to the force acting on it.
c.
The ball exerts a force on the air surrounding it.
d.
A force has acted on it.
 

 34. 

Two teams are playing tug-of-war. Each team is pulling on the rope with a force of 500 newtons. A ribbon is tied to the middle of the rope to determine the winner. Which of the following would result in the greatest acceleration of the ribbon?
a.
A player added to Team A pulls with a force of 250 newtons and a player added to Team B pulls with a force of 250 newtons.
b.
A player added to Team B pulls on the rope with a force of 120 newtons.
c.
A player added to Team A pulls on the rope with a force of 130 newtons.
d.
A player on Team B who was pulling with a force of 150 newtons leaves the game.
 

 35. 

When a gallon of milk on Earth is compared to the same gallon of milk in space, the milk on Earth has the same mass but a different __________.
a.
volume
c.
amount of matter
b.
weight
d.
inertia
 

 36. 

When two birds are pulling on a worm and the worm moves toward the first bird, you know that the forces are ____.
a.
long-range
c.
unbalanced
b.
action-reaction
d.
balanced
 

 37. 

Which of the following is NOT an acceleration?
a.
riding your bike straight down the street at a constant speed
b.
riding your bike faster when you head down a hill
c.
slowing your bike ride so you can make it up a hill
d.
stopping your bike at an intersection
 

 38. 

Two identical plastic bottles are dropped at the same time from a high tower. One of the bottles is completely filled with water and the other is only half full of water.

Which of the following statements is true?
a.
The bottles experience different air resistences so the lighter bottle will hit before the filled bottle.
b.
The bottles will hit at the same time because they are accelerating due to gravity and they encounter the same air resistence.
c.
The bottles have the same air resistence, but the filled bottle is heavier and will hit the ground first.
d.
The amount of water doesn't matter because there is no air resistence.
 

 39. 

An unbalanced force acting on an object causes it to ____.
a.
not change its velocity
c.
accelerate
b.
move at constant speed
d.
continue in a straight line
 

 40. 

Force pairs act in __________ and are __________ in size.
a.
opposite directions, unequal
b.
the same direction, unequal
c.
opposite directions,always equal
d.
the same direction, always equal
 



 
Check Your Work     Start Over