A cook heats a meal in a microwave oven. What energy transformations occur between the microwave oven and the meal?
A Electrical energy  -> light energy  -> chemical energy
B Chemical energy  -> thermal energy  -> light energy
C Electrical energy  -> electromagnetic energy  -> thermal energy
D Chemical energy  -> electromagnetic energy  -> chemical energy

c

Students were asked to identify the location of elements in the periodic table based on clues printed on game cards.

g

3 Rift valleys can form when fractures in Earth’s crust widen. The valley walls slowly move at a rate of only a few millimeters a year. Which of these best describes the type of tectonic activity that forms rift valleys?
A Rift valleys form where a continental plate moves under an oceanic plate.

B Rift valleys form where a plate slides horizontally past another plate.

C Rift valleys form where two plates move away from each other.

D Rift valleys form where an oceanic plate moves under another oceanic plate.

c

The main function of this system is to —

F control reproduction
G transport oxygen
H produce hormones
J remove waste

j

5 A student learns that the sun is classified as a medium-size star and that many stars are much bigger and brighter. However, the student observes that other stars look very dim, even through a telescope.

Why do other stars look much dimmer than the sun?
A The sun appears yellow, which is more visible than other colors.

B The sun is much closer to Earth than other stars are.

C Other stars are made up of different gases than the sun is.

D As light from other stars travels through space, it gets reflected

b

Which statement does NOT describe a relationship shown in the food web?

F Elk are prey for mountain lions.
G Mice are herbivores that consume grasses and are preyed on by snakes.
H Owls prey on rabbits and frogs.
J Rabbits consume shrubs and are parasites of grasses.

j

Which of these correctly describes the potential energy and the kinetic energy of the bicycle rider?
A When the rider is at the top of the hill, her potential energy is the greatest, and her kinetic energy is the least.
B As the rider moves up the hill, her kinetic energy increases, and her potential energy decreases.
C When the rider goes down the hill, her potential energy increases, and her kinetic energy decreases.
D As the rider reaches the bottom of the hill, her kinetic energy and her potential energy decrease.

a

g

9 A scientist added bacteria and a nutrient medium that could support the growth of the bacteria to a sterilized petri dish. No other materials were added. The graph models growth of the bacteria over time.

Which of these most likely explains why the bacterial population stopped growing?
A The bacteria competed for nutrients and died after all the nutrients were consumed.
B The bacteria did not reproduce in the system, and eventually each individual died at the end of its life cycle.
C The bacteria mutated from photosynthetic to carnivorous organisms and consumed one another until all the individuals were dead.
D The bacteria became diseased and were unable to survive in the closed system.

a

10 Which statement correctly describes the location and charge of the electrons in an atom?
F The electrons are inside the nucleus and have no charge.
G The electrons are outside the nucleus and have no charge.
H The electrons are inside the nucleus and have a negative charge.
J The electrons are outside the nucleus and have a negative charge.

j

11 An archer shot a 0.06 kg arrow at a target. The arrow accelerated at 5,000 m/s² to reach a speed of 50.0 m/s as it left the bow. During this acceleration, what was the net force on the arrow to the nearest newton?

A 300 N

B .0012 N

C 833 N

D 30 N

a

A student’s model of an area near a city depicts many activities that affect the quality of the water in the area.

How does the agricultural activity most likely affect the surface water of the area?
F Excess crop fertilizer is carried by runoff into the river, causing excess growth of water plants.
G Excess crop material accumulates on the riverbanks, slowing the movement of the river water.
H Crops reduce erosion, increasing the amount of soil entering the river.
J Crops absorb pure water from soil, causing the remaining water to contain more salt.

f

The table lists some compounds found in foods and their formulas.

Based on this information, which of these statements is NOT true?
A A molecule of sorbitol contains three more oxygen atoms than a molecule of glutamine does.
B A molecule of lactose contains twice as many atoms as a molecule of fructose does.
C A molecule of fructose contains four more atoms than a molecule of glutamine does.
D A molecule of lactose contains twice as many carbon atoms as a molecule of sorbitol does.

b

Which organelle stores the information that determines an individual’s blood type?

F Organelle 1
G Organelle 2
H Organelle 3
J Organelle 4

f

If the load exerts a strong downward force, the glue —
A destroys the force
B exerts a stronger downward force
C causes the load to accelerate upward
D exerts an upward force that is equal to the downward force

d

16 In November 2013 an object orbiting the sun seemed to disappear behind the sun. When a satellite did not detect the object, astronomers thought that the object had been destroyed when it passed close to the sun. However, when another satellite detected a small, bright object with a fan-shaped tail, astronomers proposed that the object was not destroyed. What type of object were astronomers most likely observing?
F A comet

G An asteroid

H A meteor

J A nebula

f

A few years ago the population of male blue moon butterflies on the island of Samoa declined.One hypothesis for the decline of the male butterflies is that a parasite infected the cells of female butterflies. The parasite was passed to offspring through the females’ eggs and killed the male butterfly embryos. At one point during the decline, nearly all the butterflies in the population were females, but after five years the number of males in the population increased
significantly.

Which explanation most likely accounts for the increase in the number of male butterflies in the five years after the initial parasite problem?
A Male butterflies in the population that survived were able to prey on the parasites living in the females’ egg cells.
B Female butterflies in the population that survived had a genetic adaptation that allowed them to transform into male butterflies.
C Male butterflies in the population that survived had a gene that made them resistant to the parasite, and they passed the gene on to their offspring.
D Female butterflies in the population that survived were able to protect the male eggs from the parasite and provide extra care for the male offspring.

c

Students in a science class made ball-and-stick models of the substances they were studying. The key shows the elements the students used in their models.

j

19 DDT is a pesticide that was once widely used to control agricultural pests and mosquitoes. However, this pesticide caused the eggshells of certain birds, including the brown pelican, to become fragile and thin. The adults would then accidentally crush the eggs while trying to incubate them.
What happened to brown pelican populations as a result of DDT use by humans?
A The populations increased much more slowly.
B The populations decreased as fewer eggs survived long enough to hatch.
C The populations remained stable over time.
D The populations increased as pelicans laid more eggs so that more offspring would survive.

b

20 The satellite image below shows a portion of the Namib Desert in Africa. This is an ancient, sandy desert with dunes that can be up to 305 m tall. The Namib Desert extends inland from the Atlantic Ocean between 80 km and 200 km and receives only 5 mm to 76 mm of rain each year

A satellite picture of this same area taken weeks before shows that the shape and location of some sand dunes have changed. Which of these most likely caused the changes in the dunes?
F Ocean waves
G Flowing rivers
H Blowing wind
J Crustal uplift

h

student listed how different parts of the body work to aid in the digestion of food.

Which of the following is a chemical change that occurs to the food?
A The reduction in size of food particles as food is chewed
B The movement of food to the stomach after food is swallowed
C The breakdown of molecules of food by enzymes and acid in the stomach
D None of the above

c

22 A meteor moving 468 km per minute traveling in a south-to-north direction passed near Earth in 2013. Because the meteor was only 45 m wide and was 27,700 km above Earth’s surface, it was not visible without the aid of a telescope.
Which statement describes the meteor’s motion?
F Its velocity was 7.8 km/s northward.

G Its acceleration was 468 km/s2.

H Its speed was 468 km/s northward.

J Its acceleration was 7.8 km/s2.

f

Based on the information in the table, which conclusion about the chemical reactivity of these elements is valid?

A Boron is the most reactive because it has the most protons.
B Fluorine is the most reactive because it has 7 electrons in the outer shell.
C Silicon is the most reactive because it has an equal number of protons and neutrons.
D Gallium is the most reactive because it has many more neutrons than protons.

b

Which statement best describes conditions for Earth at Position 1 in the diagram?
F There are an equal number of hours of daylight and nighttime in the Northern
Hemisphere, and the North Pole is tilted away from the sun.
G The Northern Hemisphere has the fewest hours of daylight, and Earth’s axis does not tilt at this position.
H There are an equal number of hours of daylight and nighttime in the Northern Hemisphere because Earth’s axis is not tilted in this position.
J The Northern Hemisphere has the fewest hours of daylight, and the North Pole is tilted away from the sun.

j

Which statement best describes the acceleration of the box?
A The box accelerates at 1.0 m/s² to the right because the net force is 17 N to the right.
B The box accelerates at 1.9 m/s² to the right because the greater force is to the right.
C The box accelerates at 3.0 m/s² because the combined forces cause the box to accelerate.
D The box does not accelerate, because neither force is large enough to move the box.

a

26 A silver ring reacts with compounds containing sulfur in the air to form silver sulfide, a black substance that makes up the tarnish on the surface of silver objects. To remove the tarnish from the ring, students placed it in a pan lined with aluminum foil and added hot water. Baking soda was added to the hot water and stirred. Students made observations about the process.
Which observation of this process provides evidence of a chemical reaction?

F Hot water heated the aluminum foil.

G The liquid solution changed color.

H The pan was lined with aluminum foil.

J The hot water cooled.

g

Based on these observations, which ecosystem is likely to be the least sustainable?
A Ecosystem 1, because it has the fewest species
B Ecosystem 2, because it includes both aquatic and terrestrial species
C Ecosystem 3, because it has few predators
D Ecosystem 4, because it supports many animals

a

Based on the map, volcanic activity would most likely be found at —
F Location W
G Location X
H Location Y
J Location Z

j

Which of these does NOT describe the cart’s motion on this graph?
A The cart moved 24 m away from the starting point between 2 s and 5 s.
B The cart moved toward the starting point at a speed of 3 m/s between 7 s and 12 s.
C The cart moved 11 m toward the starting point between 8 s and 10 s.
D The cart moved away from the starting point at a speed of 1 m/s for 2 s.

c

30 Which pair of properties describes the elements in Group 18?
F They are chemically stable and liquid at room temperature.
G They have eight valence electrons and are flammable.
H They are magnetic and boil at low temperatures.
J They are gaseous at room temperature and chemically stable.

j

If there is a third-quarter moon on July 2, what is the approximate date of the next full moon?
A July 9
B July 16
C July 23
D July 30

c

32 What is the total number of protons, neutrons, and electrons in a cadmium, Cd, atom that has a mass number of 112?

a 160

b 112

c 48

d 208

a

3Which of the following is most likely to cause a change in the genetic traits in an isolated population of a ground-dwelling lizard species?
A The exposure of an individual lizard in the population to radiation that causes a mutation that is not passed on to its offspring
B An unusually dry summer in the lizard population’s ecosystem
C The introduction of an invasive predator that preys on the brightest-colored individuals inthe lizard population
D A fast-moving wildfire that burns the canopy of the trees in the lizard population’s ecosystem

c

How many seconds did it take for the ball to travel 30 m during Kick 3?
F 0.5 s
G 1.0 s
H 1.5 s
J 2.0 s

j

35 A coastal area that once supported a thriving fishing industry is overfished. The number of species found living in the marine ecosystem decreases.
Which of these activities is most likely to increase the natural biodiversity in the area?
A Building artificial reefs and limiting fishing activity
B Introducing non-native species to fill unoccupied habitats and banning fishing
C Building artificial reefs and increasing fishing activity
D Eliminating non-native species and encouraging fishing for large predatory fish

a

Which of the metals was selected?
F Metal 1
G Metal 2
H Metal 3
J Metal 4

j

If Typhoon Nesat had continued along the same path, which development would most likely
have reduced its strength before it hit Hanoi?
A The formation of a low-pressure area south of Bangkok
B The formation of a high-pressure area south of Bangkok
C Cool water moving into the sea east of Hanoi
D Warm water moving into the sea east of Hanoi

c

Which organisms all consume the same producer?
F Crabs, pilchards, blennies
G Euphausiids, sweeps, water fleas
H Tiger sharks, dolphins, octopuses
J Sea urchins, crabs, octopuses

g

Based on the diagram, what spectral class does Barnard’s Star belong to?
A Spectral class O
B Spectral class B
C Spectral class A
D Spectral class M

d

Which of these best describes why the leaf fell in a crooked path instead of straight down?
F Objects with irregular shapes never fall in straight lines.
G Air currents and gravity applied changing and unbalanced forces to the leaf.
H The upward force of the air on the leaf was greater than the downward force of gravity.
J Once the leaf was in motion, it continued moving in the same direction because the forces were balanced

g

By sprouting in the rain-forest canopy, the strangler fig seedling is exposed to more —
A sunlight
B soil
C nutrients
D consumers

a

A student is using colored beads to make a model of aluminum sulfate, Al₂ (SO₄ )₃. Aluminum 3 atoms are represented by blue beads, sulfur atoms by yellow beads, and oxygen atoms by green beads.
What combination of beads should the student use for the model?
F 6 blue, 3 yellow, and 7 green
G 2 blue, 1 yellow, and 4 green
H 2 blue, 3 yellow, and 12 green
J 6 blue, 12 yellow, and 12 green

h

Green crabs carry a parasitic worm that can infect organisms that prey on the crabs. Which organism is most likely to be infected by this parasite?
A Gulls
B Barnacles
C Marsh periwinkles
D Blue mussels

a

With the use of the Hubble Space Telescope, scientists recently discovered a giant runaway star. It is 90 times larger than the sun and is very hot and blue-white in color. Why does the sun appear to be brighter than this runaway star when viewed from Earth?
F The sun is a different color than the runaway star.
G The sun is older than the runaway star.
H The sun is closer to Earth than the runaway star.
J The sun is made of different elements than the runaway star.

h

Which of the substances observed are elements?
A S, Fe, O₂, Sr, and Al
B S, O₂, and LiF
C N₂O₄, O₂,andLiF
D N₂O₄,Fe,Sr,andAl

a

Two students are working together to build a birdhouse. Student 1 applies a force of 10 N to a wooden board in order to slide it across the table to Student 2. If the force of friction resisting the student’s push is 4 N, what is the net force acting on the board?
F 4N
G 6N
H 10 N
J 14 N

g

Both primary and secondary succession begin with pioneer species that —
A change the area and make it safer from predatory organisms
B invade the area so that new organisms cannot be established
C modify the area and allow larger and more complex organisms to appear
D use up all the existing resources and prevent establishment of non-native organisms

c

Which statement best describes the positions of the two elements in the periodic table?
F The two elements are in the same period, with Element R the first element in the period and Element Q the last element.
G The two elements are side by side in the same period, with Element Q to the left of Element R.
H The two elements are in the same group, with Element R just above Element Q.
J The two elements are in the same group, with Element Q at the top of the group and Element R at the bottom.

h

d

The white-tailed ptarmigan lives at high elevations on mountains that receive a lot of snow in the winter. During the summer, the ptarmigans’ feathers are mottled brown. The birds lose the brown feathers and grow a new set of white feathers during the winter. Scientists are concerned that rising global temperatures will affect the white-tailed ptarmigan.

If global climate change leads to the elimination of snow in the habitat of white-tailed ptarmigans, which adaptation is most likely to occur over many generations?
F Birds with white feathers in areas without winter snow will be easier for predators to find. Over time this could lead to white-tailed ptarmigans that have brown feathers throughout the year.

G Birds with brown feathers in areas without winter snow will be easier for predators to find. Over time this could lead to white-tailed ptarmigans that have white feathers throughout the year.

H Birds with white feathers will be easier to see on the ground in the summer. Over time this could lead to white-tailed ptarmigans that have white feathers throughout the year.

J Birds with brown feathers will be easier to see on the ground in the winter. Over time this could lead to white-tailed ptarmigans that have brown feathers throughout the year.

f

Which of these changes would likely occur if the rate of Earth’s rotation on its axis increased?
A The length of the seasons would be shorter.
B The length of the seasons would be longer.
C The length of a day would be shorter.
D The length of a day would be longer

c

What was the ball’s average speed during the time represented in the graph?
F 0.2 m/s
G 0.5 m/s
H 5.0 m/s
J 10.0 m/s

f

Lake Victoria in East Africa is home to many species of fish called cichlids. In 1954 the predatory Nile perch was introduced to Lake Victoria. The Nile perch became the dominant fish species in the lake by the mid-1980s. The number of cichlid species in the lake decreased as the Nile perch population increased. The perch preyed heavily on cichlid species that fed on algae and debris on the bottom of the lake. Algae in the lake increased, and oxygen levels decreased. The surface area of the gills of some cichlid species has increased in just over 20 years.

Which statement explains the increase in gill surface area seen in some of Lake Victoria’s cichlids?
A Increased gill surface area has allowed the cichlids to change their diet and avoid competing with the Nile perch.
B Increased gill surface area has allowed the cichlids to be camouflaged and avoid being eaten by the Nile perch.
C Increased gill surface area has allowed the cichlids to leave Lake Victoria and establish populations in nearby bodies of water.
D Increased gill surface area has allowed the cichlids to better absorb the limited oxygen in the water

d

A student obtains two strips of magnesium, Mg, ribbon that are each 3 cm long. One strip of magnesium is placed in a test tube containing 5 mL of water, and the other strip is placed in a test tube containing 5 mL of hydrochloric acid, HCl. Both liquids are at room temperature. The student’s observations are recorded in the table.

Which statement is not supported by the student’s observations?
F A chemical reaction takes place between magnesium and hydrochloric acid.
G A gas is released in Test Tube 2.
H The substances in both test tubes are reactive only at high temperatures.
J Energy is released in the reaction involving hydrochloric acid.

h

In July 1994 the comet Shoemaker-Levy 9 collided with the planet Jupiter, as scientists had predicted. To be able to accurately predict when a comet will collide with a planet, it is essential to understand —
A the composition of a planet’s atmosphere
B the gravitational attraction that exists between all bodies
C the attraction of opposite poles of a magnet to each other
D the formation of comets

b

Based on this information, which of the organisms can produce offspring that are genetically identical to the parent organism?
F Ferns only
G Amoebas and yeasts only
H Cats, hydras, frogs, and ferns only
J Amoebas, yeasts, hydras, and ferns only

j

A star that is several thousand times brighter than the sun with a temperature lower than 4,000 K would be classified as —
A a main-sequence star in spectral class B
B a supergiant in spectral class K
C a main-sequence star in spectral class K or M
D a white dwarf in spectral class B

b

The list includes six situations.
•A book sliding across a table at a constant speed
•A ball sitting on a shelf
•A can rolling down a ramp
•A swing moving back and forth
•A car traveling at a constant speed of 15 m/s
•A bird landing on a branch
Which objects in the list experience an unbalanced force?
F The book, the ball, and the car
G The ball, the car, and the bird
H The can, the swing, and the bird
J The book, the ball, the can, and the swing

h

What is the difference between the number of electrons in an atom of selenium, Se, and the number of electrons in an atom of aluminum, Al?

a 0

b 47

c 21

d 24

c

j

a

Which student correctly identified the organic compounds in the list?
F Student K
G Student L
H Student M
J Student N

g

What are the most likely dates of the full moons?
A February 5, March 7, April 5, May 4
B February 15, March 17, April 15, May 14
C February 25, March 27, April 25, May 24
D February 29, March 31, April 29, May 28

c

Which statement best describes the energy of the two airplanes?
F Airplane W has a greater kinetic energy than Airplane X.
G The two airplanes have the same gravitational potential energy but different kinetic energies.
H Airplane X has more gravitational potential energy than Airplane W.
J The two airplanes have the same kinetic energy but different gravitational potential energies.

j

Which statement best describes the most likely effect the fire had on the river in the 12 months after it occurred?
A Less sediment flowed into the river because the fire heated up the soil and made it drier.
B The amount of vegetation increased and less sediment flowed into the river because the fire produced ash that mixed with the soil.
C More sediment flowed into the river because the fire destroyed most of the vegetation holding the sediment in place.
D More sediment flowed into the river because the fire disrupted animal habitats and caused animals to leave the area.

c

Which student’s responses are correct?
F Student 1
G Student 2
H Student 3
J Student 4

g

Which of these accurately describes the motion of the toy train?
A The toy train speeds up while going forward and then slows down.
B The toy train slows down while going forward and then moves backward.
C The toy train moves forward at a constant speed, slows down, and then stops.
D The toy train moves forward at an increasing speed, stops, and then moves forward.

c

Daphnia are tiny aquatic organisms that live in most freshwater habitats. Adults range from less than 1 to 5 mm in length. They are good swimmers and eat mostly algae. Daphnia become mature at 5 to 10 days, and an adult female can produce up to 100 eggs every 3 or 4 days during its 2-month life span. When harmful algae rapidly increase in the daphnia’s environment, daphnia can develop adaptations to tolerate the negative effects of the algae within 10 years.

What characteristic of the daphnia allows the population to adapt to environmental change?
F Its small size
G Its short generation time
H Its freshwater environment
J Its herbivorous diet

g

Strontium phosphate Sr₃ (PO₄)₂, is a crystalline substance used in medicine and industry. How many phosphorus atoms are represented in the formula for Sr₃ (PO₄)₂?

A 2
B 3
C 4
D 8

a

During which procedures did students observe an unbalanced upward force on Box 1?
F Procedures 1, 2, and 3
G Procedures 4 and 5
H Procedures 3 and 4
J Procedures 1, 3, and 5

g

Which organisms have three carnivorous predators and a consumer–producer relationship with at least one organism?
A The organisms that fit in boxes 2, 3, and 7
B The organisms that fit in boxes 5 and 7
C The organisms that fit in boxes 4 and 6
D The organisms that fit in boxes 2 and 7 only

d

a 28.00

b 49.97

c 21.97

d 6.03

b

a

f

A clerk at a hardware store performed the activities in the list.
Activities
1.Pushed a 300 N box for 5 m across a floor using 110 N of force
2.Lifted a 490 N box of tools from the floor to a shelf 1.5 m high
3.Held a 50 N clay pot for 4 minutes for a customer while the customer did more shopping
Which statement best describes the amount of work performed for the three activities?
A Activity 3 required more work than Activity 1, but Activity 3 did not require more work than Activity 2.
B Activity 1 required the same amount of work as Activity 3.
C Activity 2 required the most work.
D Activity 1 was the only activity that required work.

c

The universe has many different components. Which list places four components of the universe in the most likely order from smallest to largest?
F Planets, stars, galaxies, nebulae
G Nebulae, stars, planets, galaxies
H Galaxies, stars, planets, nebulae
J Planets, stars, nebulae, galaxies

j

35 A teacher rubbed a match against a piece of sandpaper. The match started to burn. Which statement best describes the energy changes that occurred?
A The chemical energy stored in the match changed to thermal energy and light energy.
B The thermal energy stored in the match changed to light energy and chemical energy.
C The light energy and thermal energy stored in the match changed to mechanical energy.
D The light energy and thermal energy stored in the match changed to chemical energy.

a

Which statement best describes the relative motions of the Pacific and Nazca plates?
F The Pacific and Nazca plates are both moving to the east.
G The Pacific and Nazca plates are both moving to the west.
H The Pacific plate is moving to the west, and the Nazca plate is moving to the east.
J The Pacific plate is moving to the east, and the Nazca plate is moving to the west.

h

Black walnut trees produce a nontoxic chemical that becomes highly toxic when it is exposed to air or soil. How does this chemical help black walnut trees compete with plants growing nearby?
A By attracting herbivores to the other plants
B By suppressing the growth of the other plants
C By increasing the photosynthesis rates in the other plants
D By limiting the amount of water available to the other plants

b

If Star X is 50 times as far from the sun as Wolf 359 is, how far is Star X from the sun, to the nearest light-year?

a 400

b 40

c 39

d 390

d

A student researching a northern forest ecosystem learns the following information about feeding relationships in the ecosystem.
Northern Forest Ecosystem
•Insect larvae feed on white spruces.
•Shrews and snowshoe hares are prey for lynx, red-tailed hawks, and red foxes.
•Snowshoe hares eat both willows and white spruces.
•Shrews eat insect larvae.
•Red foxes sometimes eat insect larvae.
Which food web best represents the flow of energy in these feeding relationships?

c

How do the industrial, agricultural, and residential activities of humans most likely affect the groundwater in the area?
F The activities prevent most of the water from evaporating into the atmosphere.
G Pollutants from the activities percolate through the soil and enter the water table.
H The activities replace the groundwater used.
J All of the above

g

Which of these provides evidence that a chemical reaction occurs?
A A gas is present.
B The total number of atoms remains unchanged.
C The state of matter remains the same.
D A brown gas is produced

d

Which statement best describes the cart?
F The cart was stationary with a velocity of 0 m/s for the entire 7 seconds.
G The cart was stationary except for a short burst of acceleration of 0.5 m/s².
H The cart moved at a constant velocity of 0.5 m/s for the entire 7 seconds.
J The cart accelerated at a constant rate of approximately 0.8 m/s²

h

Which table best shows some functions of the circulatory, respiratory, digestive, and endocrine systems?

d

A golfer hits a golf ball with a club. The mass of the ball is 0.05 kg. The ball accelerates at 2,000m/s² .

What is the net force, to the nearest newton, that accelerates the ball?

a 0.00000125

b 100

c 40000

d 2000

b

45 How many protons, neutrons, and electrons are present in an atom of hafnium, Hf, with a mass number of 178?
A 72 protons, 178 neutrons, 106 electrons
B 72 protons, 106 neutrons, 72 electrons
C 178 protons, 250 neutrons, 72 electrons
D 106 protons, 72 neutrons, 106 electrons

b

Which table correctly describes the functions of the cell structures listed?

h

Which substances have the same number of carbon atoms?
A Substances 1 and 2
B Substances 2, 3, and 4
C Substances 2 and 3 only
D Substances 1 and 3

d

How can Newton’s law of action–reaction best be applied to explain the movement of a rocket?
F As the fuel burns, gases push against the rocket, moving it upward.
G As the fuel burns, gases move out of the rocket and reduce air resistance.
H As the fuel burns, the mass of the rocket decreases.
J As the fuel burns, the rocket moves faster.

f

Which of these describes the mourning dove when it is part of the food web shown?
A It has a parasite–host relationship with the robin because it uses the robin’s nest.
B It has a predator–prey relationship with tent caterpillars because they both use the same resources from the sugar-maple tree.
C It has a producer–consumer relationship with sugar-maple trees because it gets food from the trees.
D It has a producer–consumer relationship with its young because it feeds its young regurgitated food.

c

Which of these is closest to the difference in elevation between the locations of the ranger and the injured hiker?
F 2,050 m
G 450 m
H 910 m
J 3,650 m

g

The student observes a great blue heron catching fish near the edge of the pond. Based on the information the student collected, which bird will compete with the great blue heron for the same hunting spots and similar prey?
A The mallard, because it hunts for fish while wading near the edge of the pond
B The pied-billed grebe, because it dives in open water to get crayfish on the bottom of the pond
C The great egret, because it hunts in water near the edge of the pond for fish and other prey
D None of these

c

Tin, Sn, is a soft white metal. It has a low melting point compared with other metals. Tin is widely used as a coating for cans of food. Which statement accurately describes atoms of tin?
F Tin atoms have 50 protons.
G Tin atoms have five valence electrons.
H Tin atoms have 119 neutrons.
J Tin atoms have 68 electrons.

f

What statement was developed most directly from these conclusions and is part of the modern cell theory?
A The functions of living things occur in cells.
B Cells exist only in multicellular organisms.
C Living things are composed of cells.
D Cells contain hereditary information.

c

In which position is it winter in North America?
F Position 1, because North America receives the most direct sun
G Position 2, because North America is tilted toward the sun
H Position 3, because North America is parallel to the sun
J Position 4, because North America is tilted away from the sun

j

Which statement about stars is correct?
F Star formation begins in a nebula.
G White dwarfs become main-sequence stars when they gain mass.
H Supergiants are stars that can absorb black holes.
J Main-sequence stars are formed by comets

f

Based on their observations, can the students correctly conclude that a chemical reaction occurred?
A No, because the metal strip was still visible
B Yes, because a new material of a different color formed on part of the metal strip
C No, because the solution stayed blue
D Yes, because the volume of the blue solution stayed the same

b

Which statement describes the energy changes that occur when water in a tea kettle is heated on a stove that uses natural gas?

F Some of the chemical energy in the natural gas transforms into thermal energy, which heats the water. Then some of the thermal energy changes into sound energy when the water forms steam and the steam leaves the kettle.

G Some of the thermal energy in the natural gas transforms into sound energy when the water becomes hot. Then some of the sound energy changes into light energy when the kettle becomes warm.

H Some of the electrical energy in the natural gas transforms into thermal energy, which causes the water to form steam. Then some of the thermal energy changes into sound energy and light energy when the steam leaves the kettle.

J Some of the light energy in the natural gas transforms into chemical energy in the water. Then some of the chemical energy changes into kinetic energy when steam leaves the kettle and into sound energy when the water boils.

f

To fight a bacterial infection, a patient was given an antibiotic to take for 10 days. After the patient finished taking the antibiotics as directed, almost all the bacteria were killed. After another 10 days, the patient was sick again with the same type of infection.
What most likely happened?
A A few bacteria survived the antibiotics and stopped reproducing.
B The patient’s high fever inactivated the antibiotic, allowing the surviving bacteria to grow rapidly.
C The antibiotic slowed the life cycle of the bacteria.
D Some of the bacteria were resistant to the antibiotic, and they reproduced

d

A 1,100 kg car comes uniformly to a stop. If the vehicle is accelerating at -1.2 m/s², which force is closest to the net force acting on the vehicle?
F 9,600 N
G 1,300 N
H 900 N
J 94 N

g

Why does autumn start in different months of the year in North America and South America?
A Earth’s orbit around the sun is not a perfect circle.
B North America has a larger landmass than South America.
C The moon has a greater pull on South America than on North America.
D Earth’s axis has a 23.5° tilt.

d

What is the primary function of this body system?
F The protection of vital organs from injury
G The chemical breakdown of food into smaller pieces
H The transport of nutrients, water, and oxygen to body cells
J The production of hormones that regulate growth and metabolism

h

What comparison can be made about the work done in the two situations?
A In Situation 1, no work was done, while 12,000 J of work was done in Situation 2.
B In Situation 1, 1,600 J of work was done, while 3,000 J of work was done in Situation 2.
C In Situation 1, no work was done, while 8,000 J of work was done in Situation 2.
D In Situation 1, 400 J of work was done, while 1,300 J of work was done in Situation 2.

a

An ecosystem that is not sustainable can break down when a natural disaster occurs. This can lead to organisms in the ecosystem either leaving the area or dying off. Increased biodiversity results in a more sustainable ecosystem because —
F a greater number of plant species means that there is less barren land
G a greater variety of species present allows more organisms to adapt after changes occur
H the transition area between two ecosystems is narrower
J there are fewer species to be affected by environmental stresses

g

How many valence electrons are in an atom of each element in Group 15 in the periodic table?

a 6

b 15

c 5

d 4

c

Which statement describes the geologic process that is most likely responsible for the formation of these mountains?
F They are along a transform plate boundary that is no longer active, so erosion is creating deep valleys.
G They are along a transform plate boundary in which plates are currently moving side by side, causing earthquakes and faults.
H They are along a plate boundary in which plates are currently converging, causing uplift and steep slopes.
J They are along a plate boundary in which plates diverged in the distant past, allowing new rock to build up.

h

A group of scientists studied some trees in a pine forest. In the densely forested areas, the trees were within 1m of each other. The scientists observed that these trees had dead branches near the ground. They measured the height above the ground at which the first living branches were found on different-sized trees in the forest. Then they repeated this procedure on the same kind of trees in an open meadow. This graph summarizes the scientists’ data.

Which inference is best supported by these data?
A Pine trees in a dense forest can grow taller than pine trees in an open meadow.
B Pine trees in a dense forest compete for sunlight with the surrounding trees.
C Pine trees in a dense forest are part of a less-complex food web than pine trees in an open meadow.
D Pine trees in a dense forest have more living branches than pine trees in an open meadow.

b

Which of the following best describes a relationship in this grassland?
A Badgers are top predators because they eat upland sandpipers and beetles.
B A producer–consumer relationship exists between lupines and ants.
C A predator–prey relationship exists between beetles and ground squirrels.
D Upland sandpipers are primary and secondary consumers because they eat grasses and grasshoppers.

d

An action–reaction pair of forces exists between —
F the aerialist’s feet and the rope
G the rope and the balancing bar
H the two ends of the rope
J the aerialist’s arms and legs
Science
Page

f

Based on these drawings, which element is the least reactive?
A Neon, because it has two energy levels with eight electrons in the second level
B Chlorine, because it has three energy levels with seven electrons in the third level
C Gallium, because it has four energy levels with three electrons in the fourth level
D Tin, because it has five energy levels with four electrons in the fifth level

a

Based on the table, a student used a measuring tape to model the distances between the sun and these nearby stars. The sun was at the starting point. Proxima Centauri was at the 10 m mark.
Which star was closest to the 20 m mark in this model?
F Barnard’s Star
G Wolf 359
H Sirius A
J Ross 248

h

Lions and cheetahs prey on wildebeests that graze in the grasslands of the African savanna. What likely effect would increased rainfall over several rainy seasons have on the populations of wildebeests, lions, and cheetahs?
A All three populations would increase.
B The wildebeest population would decrease, and the lion and cheetah populations would increase.
C The wildebeest population would increase, and the lion and cheetah populations would decrease.
D All three populations would decrease.

a

Which statement accurately describes the atoms of a specific element?
F An indium‚ In‚ atom contains 115 protons inside the nucleus and 49 neutrons outside the nucleus.
G A scandium‚ Sc‚ atom contains 45 electrons outside the nucleus and 21 neutrons inside the nucleus.
H An aluminum‚ Al‚ atom contains 27 electrons and 27 protons inside the nucleus.
J A zinc‚ Zn‚ atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus

j

A student notices that the moon is full one evening. Which sequence of moon phases will the student observe over the next eight days?
A Full, waning gibbous, third quarter
B Full, waning gibbous, first quarter, waning crescent
C Full, new, waning gibbous
D Full, waxing gibbous, new, waning crescent

a

Which statement does NOT correctly compare silicon with another element?

F Silicon is a better conductor of electricity than sulfur.

G Silicon conducts electricity as well as copper does.

H Silicon is a solid at room temperature, but argon is a gas.

J Silicon is less malleable than silver.

g

At which location does the marble have maximum kinetic energy?
A Location W
B Location X
C Location Y
D Location Z

c

j

How are the convection currents in the student’s model different from the convection currents in Earth’s atmosphere and oceans?
A The warm air in Earth’s atmosphere and the warm water in Earth’s oceans sink instead of rise.
B The heat source for Earth’s atmosphere and oceans is the sun, which heats from above instead of below.
C Convection cells in Earth’s atmosphere and oceans flow in the same direction instead of opposite directions.
D Cold air in Earth’s atmosphere and cold water in Earth’s oceans are less dense than warm air and warm water instead of being more dense.

b

Based on the life-cycle information, which statement best describes the relationship between
the nest fly larvae and the young birds?
F The larvae are prey for the young birds.
G The larvae are predators of the young birds.
H The young birds are hosts for the larvae.
J The young birds are consumers of the larvae.

h

Sulfur hexafluoride, SF₆, is a very stable, nonflammable gas at room temperature. It is used in many electronic products because it is a good electrical insulator.
Which statement describes the composition of sulfur hexafluoride?
A SF₆ is a compound containing atoms of sulfur and fluorine.
B SF₆ is a compound that contains seven identical atoms.
C SF₆ is an element with sulfur in the atom’s nucleus and fluorine outside the nucleus.
D SF₆ is an organic compound composed of long chains of sulfur atoms surrounded by fluorine atoms.

a

Four boxes are sliding with constant speed before each box experiences an unbalanced force of 8 N. Which box would experience the greatest acceleration when the unbalanced force is applied?
F The box with a mass of 2 kg
G The box with a mass of 4 kg
H The box with a mass of 6 kg
J The box with a mass of 8 kg

f

mid-ocean ridge is located at the boundary of two tectonic plates. Which diagram correctly models the relative plate motion on each side of a mid-ocean ridge?

b

Assuming the students did not make any careless errors, what likely explains these changes in mass?
F Procedure 1: All the reactants were liquids that evaporated. Procedure 2: A gas was formed as one product, and it escaped into the air.
G Procedure 1: One of the reactants was converted to thermal energy. Procedure 2: All the products were liquids.
H Procedure 1: The reactants were liquids with different densities. Procedure 2: The reactants were combined into only one product.
J Procedure 1: One of the products was a gas that escaped into the air. Procedure 2: A gas from the air reacted with one of the other reactants.

j

What is the most likely explanation for the body-size distribution of house sparrows shown on the map?
A Cold temperatures in the North favored the survival of populations of larger sparrows over populations of smaller sparrows.
B High elevations in the West provided a survival advantage for populations of larger sparrows over populations of smaller sparrows.
C Warm temperatures in the South allowed populations of larger sparrows to survive over populations of smaller sparrows.
D Coastal environments in the East tended to give a survival advantage to populations of larger sparrows over populations of smaller sparrows.

a

j

Four students were asked to complete a table for a science assignment. Each student selected one chemical element from each of four groups in the periodic table and then classified each element as a metal, a nonmetal, or a metalloid.
Which table was completed correctly?

b

A block is pulled 0.90 m to the right in 2.5 s. What is the block’s average speed to the nearest hundredth of a m/s?

A 0.9

B 2.25

C 0.36

D 0.63

c

This topographic map represents the elevation of an area 100 years ago. At that time the highest point had an elevation of 214 m. The highest point has since eroded a total of 7 m.

a

Some areas of an ocean are known as dead zones. These zones form when excess organic material decomposes. This increased decomposition uses up the oxygen from the water. Which human activity is most affected by the increasing number of dead zones in the ocean?
F Offshore oil drilling, because water in dead zones is toxic
G Commercial fishing, because fish cannot survive without oxygen
H Commercial shipping, because dead zones change the course of ocean currents
J Sand mining, because oxygen is not available to form the sands on ocean beaches

g

Which area of the diagram represents the white dwarfs?
A Area M
B Area X
C Area P
D Area Z

d

Both the esophagus and the small intestine are involved in the digestion of food. The esophagus squeezes food into the stomach by wave-like muscle contractions. Peptidase enzymes in the small intestine break food molecules into smaller molecules.
Which statement best describes changes to food during digestion?
F The muscle contractions result in physical changes, while the action of the peptidase results in chemical changes.
G The muscle contractions and the action of the peptidase both result only in physical changes.
H The muscle contractions result in chemical changes, while the action of the peptidase results in physical changes.
J The muscle contractions and the action of the peptidase both result only in chemical changes.

f

The teacher asked the class to calculate the acceleration of the crate based on the crate’s mass and the force she applied. What conclusion can be made about the difference between the calculated acceleration and the actual acceleration that occurred in the trials?
A Another force in the direction of the motion produced a lower acceleration than calculated.
B An opposing force caused by friction produced a lower acceleration than calculated.
C Another force in the direction of the motion produced a higher acceleration than calculated.
D An opposing force caused by friction produced a higher acceleration than calculated.

b

Wheat was one of the first plant crops that humans domesticated. In the process of domestication, the wild form of wheat was eventually changed into a form more suited to human agricultural practice.
Early farmers most likely used seeds only from wheat plants with —
F larger grains that could produce more food per plant
G taller stems that could block sunlight from weeds growing at ground level
H larger flowers that could be sold for additional income
J thinner stems that could endure heavy winds

f

Which sentence best describes how energy flows through this pyramid?
A Energy is transferred down each level of the energy pyramid.
B The energy lost at each level is consumed by organisms in the top level.
C Energy is transferred from organisms in one level to those in the level above.
D The organisms at the bottom level provide energy directly to organisms in all the other levels.

c

j

41 What keeps planets in the solar system from moving in straight lines through the galaxy?
A Light energy
B Gravity
C Inertia
D Potential energy

b

Whitetip reef sharks spend most of the day lying on the ocean floor. While remaining still, these sharks pump water across their gills. The movement of water across their gills is necessary for —
F staying cool
G accessing food
H obtaining oxygen
J avoiding predators

h

The Guam rail is a flightless bird found on the island of Guam. It builds a shallow nest on the ground and lays eggs throughout the year. There are no native species of snakes on Guam, so the Guam rail had no experience with snake predators until the brown tree snake was accidentally introduced sometime between 1944 and 1952. These snakes, which eat a wide variety of animal species, quickly established a large population on Guam.

How was the Guam rail most likely affected by the introduction of the brown tree snake?

A The brown tree snake ate only species that lived in trees, so it had no effect on the Guamrail.

B The Guam rail quickly developed the ability to fly in order to escape from the brown treesnake.

C The population of the Guam rail declined, and the species nearly became extinct.

D The Guam rail began to build its nests in trees.

c

Different relative positions of the sun, the moon, and Earth have different effects on Earth’s oceans. Which model shows the positions of the sun, the moon, and Earth that have the greatest effect on ocean tides?

j

This appliance dries clothes primarily by converting —

A electrical energy to heat and mechanical energy

B mechanical energy to heat and electrical energy

C electrical energy to heat and light

D mechanical energy to heat and vaporization

a

Which list of characteristics describes organisms classified as animals?

F Unicellular, prokaryotic, autotrophic

G Multicellular, eukaryotic, heterotrophic

H Unicellular, eukaryotic, heterotrophic

J Multicellular, eukaryotic, autotrophic

g

5 An athlete is trying to lift some weights. He successfully lifts 200 N weights, but when he tries to lift 400 N weights, he is unsuccessful.

A The athlete does no work on either the 200 N weights or the 400 N weights

B The athlete does no work on the 200 N weights but does work on the 400 N weights.

C The athlete does work on both the 200 N weights and the 400 N weights.

D The athlete does work on the 200 N weights but does no work on the 400 N weights.

d

The main function of this human body system is to —

F sense odors in the environment

G exchange gases with the environment

H chew food as it enters the mouth

J trap particles that enter the nose

g

c

Based on the diagram, which of the following statements is valid?

F Owls are predators of bats, and bats are predators of moths.

G Beetles compete with bats and cave spiders.

H Snakes prey on bats and owls.

J None of the above

f

Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns?

A The shape of the coal changes.

B Oxygen is present.

C A new substance is produced.

D Coal is made up of more than one element.

c

A student wants to use a spinning basketball to model the day-and-night cycle on Earth.

What should the student do in order to best model the cause of the day-and-night cycle?

F Spin the ball in different directions

G Tilt the ball while it is spinning

H Paint one half of the ball black and the other half white

J Shine a bright light on one side of the ball

j

The atoms of a certain element each contain 11 protons and 1 valence electron. Which statement correctly identifies this element and describes its chemical reactivity?

A The element is sodium, and it is highly reactive.

B The element is fluorine, and it is not very reactive.

C The element is sodium, and it is not very reactive.

D The element is fluorine, and it is highly reactive.

a

A bus travels 20 km in 30 minutes. What is the average speed of the bus?

F 20 km/h

G 30 km/h

H 40 km/h

J 50 km/h

h

Why are there significantly more thunderstorms in Florida than in California?

A The state of Florida is smaller than the state of California.

B The air in Florida is more stable than the air in California.

C The air above Florida holds less moisture than the air above California.

D The ocean currents near Florida are warmer than the ocean currents near California

d

Which of these best explains why the coin fell straight down into the cup instead of remaining on the index card?

F The coin was at rest until the card was removed, so it tended to remain in the same location. Once the card was gone, the unbalanced force of gravity caused the coin to fall.

G Moving the card applied an action force on the coin. Since the card was gone, gravity applied a reaction force on the coin.

H The card had less mass than the coin, so a smaller force of gravity acted on the card. The larger force of gravity on the coin made it fall.

J The acceleration of the coin falling into the cup was equal and opposite to the acceleration of the card.

f

Which unknown substance is most likely carbon?

A Substance 1

B Substance 2

C Substance 3

D Substance 4

b

Which of these human activities is most likely to cause the excessive growth of phytoplanktonin the world’s oceans?

F The use of chemical fertilizers that are carried by runoff into rivers

G The logging of old-growth forests, which results in erosion

H The spraying of chemical herbicides that reduce carbon dioxide in the air

J The mining of fossil fuels, which requires digging underground tunnels

f

An atom of a certain element has 36 protons, 36 electrons, and a mass number of 84. At room temperature this element is a very stable gas. How many neutrons are in this atom?

a 84

b 36

c 48

d 120

c

What plate boundary feature is also shown?

F A ridge formed by an inactive convergent boundary

G A valley forming at an active divergent boundary

H A fault forming at an active transform boundary

J A volcano formed by an active transform boundary

h

a

Based on this diagram, how do the characteristics of Star 1 and Star 2 compare?

F Star 1 is cooler and less bright than Star 2.

G Star 1 is hotter and brighter than Star 2.

H Star 1 is cooler and brighter than Star 2

.J Star 1 is hotter and less bright than Star 2.

g

Which two types of organisms in this aquatic food web have a producer–consumer relationship?

A Microscopic algae and white suckers

B Small invertebrates and amphipods

C Phytoplankton and mummichogs

D Amphipods and channel catfish

a

h

Water with which of these conditions would cause the most competition for resources among all three species of fish?

A Very cold, very clear, and very fast

B Very warm, very clear, and very slow

C Mild temperatures, some suspended particles, flows very fast

D Mild temperatures, some suspended particles, flows at a medium speed

d

The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed.

Charcteristics of a group of elements

• shiny
• Is solid at room temperature
• Has atoms with two valence electrons

Which of these elements is in this group?

F Lithium

G Strontium

H Aluminum

J Silicon

g

The student used the diagram to describe changes in the potential and kinetic energy of the water. At which location is the gravitational potential energy of the water the greatest?

A Location W

B Location X

C Location Y

D Location Z

a

Which area of the coastline has most likely experienced the greatest effect of erosion from waves over hundreds of years?

F Area N

G Area P

H Area S

J Area T

h

Which of these formulas contain equal numbers of nitrogen atoms?

A Formulas I and III

B Formulas I and IV

C Formulas II and III

D Formulas I, II, and V

d

Based on the dichotomous key, in what order should this insect be classified?

F Mantodea

G Raphidioptera

H Coleoptera

J Lepidoptera

h

Quasars are extremely distant celestial bodies. Investigators using a special telescope determined that a certain quasar was emitting waves with a frequency of 14.1×10⁹ Hz. An electromagnetic spectrum is shown.

The investigators were most likely using a telescope that detects —

A microwaves

B visible light

C x-rays

D gamma rays

a

A basketball with a mass of 0.60 kg is accelerated with a force of 10.8 N. If resisting forces are ignored, what is the acceleration of the basketball to the nearest m/s²?

a .06 m/s²

b 18 m/s²

c .648 m/s²

d 11 m/s²

b

Scientists are studying the effects of climate change on the Baltic Sea. Some scientists predict that if current trends continue, the Baltic Sea will become less salty, and it will contain less dissolved oxygen. As a result of these changes, the Baltic Sea will have less biodiversity.

Which statement best explains why biodiversity in the Baltic Sea could decrease if these changes occur?

A Fewer types of plants and animals are found in warm water than in cool water.

B Plants and animals adapted for living in saltwater will grow more slowly in water that has less salt.

C Plants and animals adapted for living in saltier conditions will not be able to survive and reproduce.

D Animals adapted for living in warm water will eat all the plants and animals adapted for living in cool water.

c

What lunar phase occurred on July 4, 1776?

F Waning gibbous

G Waxing gibbous

H Waning crescent

J Waxing crescent

f

Aluminum, sulfur, and chlorine are elements found on the periodic table. Tests involving these three elements would show that at normal room temperature —

A sulfur is malleable and aluminum conducts electricity

B chlorine is malleable and conducts electricity

C aluminum is malleable and conducts electricity

D all three elements are malleable and conduct electricity

c

What do these volcanoes indicate about plate tectonics in the region?

F The volcanoes form an island arc, indicating a converging plate boundary.

G The volcanoes form a line, indicating a diverging plate boundary.

H Two plates are moving past each other, causing faulting and magma formation.

J Two plates are moving apart, creating new seafloor

f

The total mass of the cyclist and the bicycle is 100.0 kg. Based on this information, what is the acceleration of the cyclist?

A 0.66 m/s² backward, because the force of the air slows the cyclist down

B 0.66 m/s² forward, because the applied force is greater than the force of the air

C 2.3 m/s² backward, because the forces are opposite and not equal

D 2.3 m/s² forward, because the cyclist’s inertia is greater than the force of the air

b

How many atoms are represented in the reactants of this equation?

F 6

G 12

H 24

J 36

j

Which of the following best describes the velocity of an object?

A 30 m/s

B 30 m east

C 30 m/s east

D 30m/s²

c

What height in meters must the student climb in order to reach the top of the hill?

A 300

B 253

C 303

D 250

b

A chemist is identifying the elements present in a sample of seawater. What characteristic of an element’s atoms always determines the element’s identity?

A The number of protons

B The number of neutrons

C The location of valence electrons

D The number of valence electrons

a

Copper compounds are used in large amounts to control the growth of algae and other aquatic plants. Copper interferes with photosynthesis in these organisms. What would be the most likely result of an accidental spill of these compounds in an aquatic environment?

F The fish would grow larger than usual.

G The zooplankton population would increase.

H The plants would increase in size but decrease in number.

J The plant populations would be reduced.

j

In the summer many people enjoy going to the beach.

Which diagram shows the position of Earth when it is summer in Argentina?

b

If Species B were removed from the rocky areas it shares with Species A, Species A would most likely inhabit —

F Zone I only

G Zones I and II only

H Zone III only

J Zones I, II, and III

j

Based on the law of action–reaction, in what direction will the sled most likely move as the student jumps off?

A North

B South

C East

D West

c

How many predators shown in this food web are omnivores?

a 1

b 2

c 3

d 4

a

In the early 1900's many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernest Rutherford completed an experiment that changed the concept of an atom. His discovery led to the understanding that an atom consists mostly of empty space with —

A protons orbiting a dense nucleus made of electrons and neutrons

B electrons orbiting a dense nucleus made of protons and neutrons

C neutrons and protons orbiting a cloud of electrons

D electrons and protons orbiting a cloud of neutrons

b

Tropical rain forests have the greatest biodiversity of any type of land ecosystem. How does biodiversity contribute to the sustainability of an ecosystem?

F The presence of more species with different adaptations makes it more likely that some organisms will survive an ecological disaster.

G Greater genetic variation within species makes it more likely that some individuals will survive a disease outbreak.

H The presence of a variety of herbivore species that can feed on a large number of different producer species helps ensure abundant prey for predators in the ecosystem.

J All of the above

j

Based on the weather map, which city will most likely experience decreasing temperatures during the next 24 hours?

A Denver, because it is raining there

B Minneapolis, because a cold front is approaching

C Atlanta, because a warm front is approaching

D Houston, because it is in a high-pressure area

b

For an investigation a student poured a blue solution of CuSO₄ into a beaker. The student placed a shiny, silver-colored strip of zinc metal in the solution and observed the changes.

The student inferred that a chemical reaction occurred. What evidence supports this inference?

F A dark solid formed on the zinc metal.

G The zinc metal remained silver-colored and shiny.

H The CuSO₄ solution turned blue when the zinc metal was added.

J None of these

f

During which part or parts of the marble’s fall did the marble experience unbalanced forces?

A Part 1 only

B Parts 1 and 2 only

C Part 3 only

D Parts 2 and 3 only

b

Which of these correctly compares the masses of different objects in the universe?

F A moon has less mass than a star and more mass than the planet it orbits.

G A planet has less mass than a galaxy and more mass than the star it orbits.

H A galaxy has less mass than a moon and more mass than a planet.

J A star has less mass than a galaxy and more mass than a planet.

j

Which two elements on the periodic table are in the same period?

A Sn and Rb

B F and Cl

C K and Ba

D Se and Te

a

A student runs two times around a running path at a local park. Each lap is 3 km. The student completes the first lap in 20 minutes. The student then sits on a bench and rests for 5 minutes before completing the second lap in 25 minutes. Which graph best represents the student’s motion

h

Which of these cell components are most involved in determining the basic shape of each girl’s face?

A Genes, chromosomes, and nucleus

B Cytoplasm, chloroplasts, and genes

C Vacuoles, nucleus, and chromosomes

D Chromosomes, chloroplasts, and vacuoles

a

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

F H₃PO₄

G H₂SO₄

H HClO₃

J H₂O

g

Some students used a globe to model the rotation of Earth. They shaded in Texas on the globe, as shown below. They rotated the globe and observed that Texas was inexactly the same place after each rotation.

The students could rotate the globe quickly or slowly. If the globe could rotate only at the rate that Earth actually rotates, about how long would each complete rotation take?

A 30 days

B 60 minutes

C 24 hours

D 365 days

c

A student observes ice forming on the edge of a school building.

At what temperature did the water outside the school building most likely begin to change to ice?

F 100°C

G 32°C

H 25°C

J 0°C

j

The caterpillars of monarch butterflies eat milkweed leaves. Milkweed leaves contain sap that is toxic to many animals but not to monarch butterfly caterpillars. This sap makes the monarch butterfly caterpillars toxic to predators and protects them from being eaten.

Which of these is an inherited trait of monarch butterfly caterpillars?

A The size of the milkweed leaves that the caterpillars eat

B The ability of the caterpillars to eat toxic leaves without being harmed

C The number of milkweed leaves the caterpillars eat each day

D The number of leaves on the milkweed plants that the caterpillars visit eachsummer

b

The picture below shows a child standing in a swimming pool.

Why does the lower part of the child appear so much different in size from the upperpart?

F The light rays that travel through water and then into air are refracted.

G The light rays that travel through water and then into air are enlarged.

H The light rays that travel through air and then into water are reflected.

J The light rays that travel through air and then into water are reduced.

f

Animals and plants use substances that cycle through the environment. Which substance is needed by plants to survive and is released into the environment by animals?

A Oxygen

B Sugar

C Salt

D Carbon dioxide

d

Which of the methods of generating electricity shown below does NOT use alternative energy resources?

f

A student makes a model of the water cycle by using a cup, some water, and plasticwrap. After the student places the model near a sunny window, moisture forms on the inside of the plastic wrap.

What change is the student most likely observing in this model?

A Freezing

B Condensation

C The warming of air

D The formation of clouds

b

The Rio Grande Valley is located at the southern tip of Texas at the end of a long river known as the Rio Grande.

How did the delta at the end of the Rio Grande form?

F Sand and mud from the Gulf of Mexico were washed ashore by tsunamis.

G The river cut through the solid bedrock of the valley.

H The river deposited large amounts of sediment from land erosion.

J Hurricanes pushed soil and debris from the Gulf of Mexico onto the land.

h

Which table shows the correct role of each organism in the food chain below?

a

A student observes that the craters on the moon are different sizes. The student designs an experiment to study the formation of craters. The materials for the experiment are marbles and a pan of flour. The student makes a hypothesis that the size of the craters made on the surface of the flour will depend on the height from which the marble is dropped. Some of the steps in the student’s experiment are described below.

Which of these is most likely Step 3 in the student’s experiment?

F Drop the same marble from different heights into the pan of flour

G Drop marbles of different masses from the same height into the pan of flour

H Drop marbles of different sizes from different heights into the pan of flour

J Drop a single marble one time into the pan of flour

f

A teacher is setting up the terrarium shown below in a science classroom.

Which of these organisms is best suited for the terrarium?

A Blue jay

B Lobster

C Snail

D Water lily

c

Several students investigate the characteristics of soil. The students observe samples of common soils. In one sample they observe that water drains through the soil easily. When they rub the soil between their fingers, it feels rough and scratchy, and its particles feel hard. The soil the students observed is most likely —

F clay

G silt

H loam

J sand

j

The life cycles of a butterfly and a chigger are shown below.

How is the life cycle of chiggers different from the life cycle of butterflies?

A Chigger larvae have legs.

B Chiggers have a nymph phase.

C Chiggers go through metamorphosis.

D Chigger larvae hatch from eggs.

b

A student measures the mass of several substances and records the results in the table below

What is the difference in grams between the total mass of the liquid substances and the total mass of the solid substances used in the investigation?

a 155

b 140

c 168

d 183

c

The diagram shows the metal posts that are usually found on a battery.

The battery can be connected to a bell and a switch to produce sound. Which statement best explains why there are two metal posts on the battery?

A The battery needs only one metal post to connect to the bell, but the other metal post is present in case the first post fails to work.

B The battery needs to form a complete circuit that starts with one metal post and ends with the other metal post.

C One metal post makes a complete circuit with the switch, and the other metal post makes a complete circuit with the bell.

D One metal post makes the bell start to ring, and the other metal post makes the bell ring louder.

b

The ocotillo is a desert plant with long, straight branches. Its leaves are small and appear for only a short time after a rain. Most of the time, the branches of the ocotillo do not have leaves. Maple trees grow in areas where water is more abundant than in the desert. Maple leaves can be very large and are present for most months of the year.

Ocotillo plants are better adapted for surviving in the desert than maple trees because the characteristics of ocotillo leaves —

F allow more sunlight to reach the soil

G prevent the plant from producing flowers

H encourage the release of carbon dioxide from the stems

J reduce the amount of water lost through evaporation

j

When a powdered drink mix was added to water, the liquid turned orange. A student decided the taste was too strong, so he poured out half of the liquid and added more water. Which of the following most likely occurred when more water was added?

AThe physical state changed.

B The orange color became lighter.

C The liquid had a sweeter taste.

D None of the above

b

Each school year for 30 years, the amount of rain that fell at a school was measuredand recorded. Tracking rainfall over a long period provides the most informationabout which characteristic of an area?

F Climate

G Temperature of one day

H Weather

J Type of soil

f

A class is learning about states of matter. The teacher shows the students how to setup the investigation shown in the diagram.

What kinds of energy are needed in this investigation to change the state of matter of the candle?

A Light, mechanical, and thermal

B Electrical and thermal

C Mechanical, light, and electrical

D Thermal and mechanical

b

All of these are related to the formation of oil or natural gas EXCEPT—

F decomposed animals

G decayed plants

H sedimentary rocks

J active volcanoes

j

A prickly pear cactus is shown below.

The roots of the prickly pear cactus spread out in a wide underground network. How does this type of root system benefit a prickly pear cactus?

A By producing fruit and storing water

B By capturing sunlight and getting rid of waste materials

C By absorbing water and supporting the plant in loose, sandy soil

D By releasing nutrients into the sandy soil and taking in oxygen

c

Some students paint the inside of several boxes. They paint each box a different color. They observe that the inside of the box painted white looks brighter than the others. What is the most likely reason this box looks brighter?

F More light is reflected off white paint.

G More light is refracted by white paint.

H More light passes through white paint.

J More light is absorbed by white paint.

f

A teacher wears protective gloves to lift a metal pan filled with boiling water from a hot plate. Why are the protective gloves necessary?

A The metal pan creates thermal energy.

B The metal pan insulates thermal energy.

C The metal pan conducts thermal energy.

D The metal pan reduces thermal energy.

c

A student hiking in a rocky area on a mountain notices that wide, deep cracks have formed in some of the large rocks. Some of the cracks are so large that the rockshave broken apart. Which process most likely caused these rocks to crack and break?

F Erosion by wind

G Water freezing and thawing

H Erosion by fast-moving water

J Sediments being deposited

g

Prairie dogs eat plants and dig underground tunnels. Prairie dog tunnels help breakup hard prairie soils, and the animals’ waste adds nutrients to the soil. In the past,large groups of prairie dogs lived in many parts of the U.S. Great Plains, but people have destroyed most of these colonies.

Which of these will most likely happen when prairie dogs are removed from an area?

A The population of predators that eat prairie dogs will decrease.

B The population of plants that prairie dogs eat will decrease.

C The nutrients in the soil will increase.

D The number of underground tunnels will increase.

a

Most cars have lights, power locks, radios, and other equipment that use electricity. Electric circuits power this equipment. Each circuit has a fuse that completes it. The picture below shows one type of fuse a car may have.

Which of these describes one thing that could happen if the wire in a car fuse burns out?

F The car’s lights will burn brighter.

G The car’s radio will not work.

H The car’s turn signal will blink too slowly.

J The car’s power windows will open faster.

g

The diagram above shows the process of evaporation over the ocean. What is the most likely effect of this process on the land areas nearby?

A Increased drought conditions

B Decreased erosion of the shoreline

C Increased precipitation

D Decreased solar energy

c

In a food chain, energy does NOT flow directly from —

F producer to decomposer

G producer to consumer

H consumer to decomposer

J consumer to producer

j

A student made a mixture using equal amounts of salt and pepper. The salt grains were the same size as the pepper grains. What should the student do to most easily separate the pepper from the salt?

A Use a pair of tweezers to remove each grain of pepper

B Run a small magnet through the mixture to attract the pepper

C Put the mixture in water and filter the pepper out of the water

D Use a strainer with a fine wire screen to remove the pepper

c

Which of these is a learned behavior of a dog?

F Begging for food

G Drinking water

H Panting on a hot day

J Chewing on a bone

f

A student designs an experiment to test the force of a spring using a spring launcher and four spheres with the same diameter but with different masses.

What other piece of equipment would be most useful for this experiment?

A A graduated cylinder to measure the volume of each sphere before the sphere islaunched

B A beaker to collect the spheres after they are launched

C A stopwatch to measure how long it takes to load each sphere on the spring

D A meterstick to measure the height each sphere reaches after the sphere islaunched

d

The model below shows layers of sediment on the floor of an ocean.

Which of the following best explains how these layers can become rock over many years?

F Sand in the sediment melts and turns into rock.

G The weight of the water compacts the sediment into rock.

H Changing water temperatures turn sand in the sediment into rock.

J Pollution caused by humans turns the sediment into rock.

g

Objects that blow into a swimming pool or that are dropped into the pool by swimmers need to be removed. These objects include foam cups, keys, and coins.Which of the following explains a useful method for removing some of these objects?

A The keys and coins are less dense than water, so they can be easily picked up off the bottom of the pool by divers.

B The foam cups have the same density as water, so they can be crumbled up for removal by the pool filter.

C The foam cups are less dense than water, so they can be removed from the surface with a pool cleaning net.

D The keys and coins have the same density as water, so they can be washed away when the pool is drained.

c

Most kangaroos have large, heavy tails, while spider monkeys have long, thin tails.Kangaroo tails are useful when the kangaroos are hopping and also when they are crawling around on the ground to feed. Spider monkey tails are useful when the spider monkeys are moving through trees. Both of these animals use their tails primarily for —

F grabbing and holding their food

G supporting and balancing their body

H attracting the attention of other animals

J carrying their young

g

Shadows cast by objects change throughout the day. The picture below shows the shadow cast by a tree at 3:00 P.M.

a

The picture below shows a pulley system that can be used to lift a box.

Which of these should a person do to lift the box?

F Tie the end of the rope to the box

G Tie the end of the rope to the ceiling hook

H Pull the end of the rope downward

J Allow the end of the rope to move upward

h

The food web below is made up of organisms that live in a forest.

Which change would most likely occur if all the producers in this ecosystem were moved?

A The mice would become the new producers.

B All the animals would either die or move away.

C The number of mice would increase.

D All the animal populations would increase.

b

Which alternative energy source is generated beneath Earth’s crust and can be usedto heat buildings?

F Hydroelectric energy

G Geothermal energy

H Wind energy

J Solar energy

g

A cook uses the ingredients listed below to prepare a meal.

d

The model shows a special glass fiber that is thinner than some metal wires. When light enters one end of the fiber, it moves through the fiber as shown.

After the light leaves the fiber, it travels —

F in a straight line

G back into the fiber

H around the fiber

J in a curve

f

Some facts about birds called cattle egrets are listed below

Which of these facts best describes how these birds depend on other animals to survive?

A Fact 1

B Fact 2

C Fact 3

D Fact 4

c

One of the brightest objects in the night sky is a planet that is closer to the sun than Earth is. What is the name of this planet?

F Mars

G Saturn

H Jupiter

J Venus

j

Wild Texas hogs, similar to the one shown below, are descended from hogs brought here from other countries.

These wild hogs eat many different kinds of foods, including plants, fungi, and insects. Besides being very destructive to the habitats of other animals, how do wild hogs most likely harm other animals?

A By competing with other animals for food

B By moving slower than most other animals

C By causing other animals to reproduce more

D By eating foods that no other animals eat

a

Rube Goldberg was an artist who drew cartoons that showed a very complicated way to do a simple task. The picture below shows a cartoon like the ones Goldberg drew.

Which form of energy is used to turn on the switch?

F Light energy

G Thermal energy

H Electrical energy

J Mechanical energy

j

A student lets a toy car roll four times down a ramp that is 1 m long. Each time the student covers the surface of the ramp with a different material. The student measures the time it takes the car to roll down the ramp and records the results in the table below.

Which of these would be the best conclusion based on the data in the table?

A Different surfaces affect how fast a toy car accelerates.

B Different toy cars travel at different speeds.

C Gravity has little effect on the speed of toy cars on different surfaces.

D Air resistance is the greatest factor in limiting the acceleration of different toy cars.

a

The diagram below models Mercury and Venus orbiting the sun.

What force causes Venus to travel along a curved path instead of moving in a straight line as indicated by the dashed line in the diagram?

F Electromagnetic attraction between the sun and Venus

G Gravitational attraction between the sun and Venus

H Electromagnetic attraction between Mercury and Venus

J Gravitational attraction between Mercury and Venus

g

Before the Industrial Revolution in England, the peppered moth was commonly found on tree trunks that had light-colored lichen on the bark. Most of the peppered moths were a light gray-brown color similar to that of the lichen. A few of the moths had a mutation that made them a dark gray-brown color.

During the Industrial Revolution, coal-burning factories produced black soot that covered the trees and killed the lichen in and near cities. In these areas the number of dark peppered moths increased, while the number of light peppered moths decreased. What contributed to this change?

A The soot-covered trees camouflaged the dark moths.

B The dark moths preyed on the light moths.

C Bird populations increased in the areas near the factories.

D The dark moths laid fewer eggs than the light moths.

a

Four students were asked to classify the activities of the people in the picture below as examples of either potential or kinetic energy.

j

The Prairies Region and the Cross Timbers are located in north-central Texas. The graph below shows information about eating habits of white-tailed deer in these regions.

A Cross Timbers rancher is concerned about competition between the ranch animals and the deer. Based on the graph, which ranch animals compete for the most food with white-tailed deer?

A Cattle that eat grass and feed

B Goats that eat weeds and shrubs

C Turkeys that eat seeds and fruit

D Hogs that eat fruit, seeds, and feed

b

Many processes occur in the digestive system. Which process is best classified as a physical change?

F Saliva converting the starch molecules in crackers into simple sugars

G Digestive enzymes breaking down proteins into smaller fragments

H Bacteria converting lactose into simple sugars in the intestines

J Teeth grinding an almond into smaller pieces in the mouth

j

When Charles Darwin visited the Galápagos Islands in the 1800's, he observed many types of organisms that were similar but lived on different islands. The four species of mocking birds found on the Galápagos Islands are shown below. Each species lives on a different island.

These species are very similar, but the Hood mockingbird has a longer beak than the other three species. Which of the following best explains this difference?

A The Hood mockingbird needs a longer beak for defense against predators.

B The Hood mockingbird originated from a different type of bird than the other species.

C The Hood mockingbird’s longer beak is an adaptation to the food available in the bird’s habitat.

D The Hood mockingbird’s beak stretched to reach its food, and the longer beak was passed down to its offspring.

c

A Hertzsprung-Russell diagram is shown below.

Based on this diagram, which type of stars would belong to spectral class M and have the highest luminosity?

F Main-sequence stars

G Giants

H White dwarfs

J Supergiants

j

When a lion eats a zebra and then uses the energy from the zebra to run, the lion’s body converts —

A chemical energy to mechanical energy

B electrical energy to chemical energy

C chemical energy to light energy

D mechanical energy to chemical energy

a

Some students in a chemistry lab conducted an investigation in which they added four different solid substances to separate beakers of water. They stirred the mixtures for one minute and then recorded their observations in the table below.

Which substance most likely caused a new substance to be formed when mixed with water?

F Substance 1

G Substance 2

H Substance 3

J Substance 4

g

Which of these correctly describes a relationship between organisms in the soil food web below?

A Protozoa get nutrients from small arthropods.

B Mammals are predators of birds.

C Nematodes prey on arthropods.

D Bacteria get nutrients from organic matter.

d

Scientists recently discovered that rocks collected from the Franklin Mountains in West Texas and rocks collected from mountains in eastern Antarctica were exactly the same age. Further research showed that the rocks were chemically and geologically the same and came from the same magma source. This discovery provides evidence of —

F coastal erosion

G plate tectonics

H ocean currents

J glacial melting

g

Galveston Bay, an estuary in Southeast Texas,is shown below. The amount of salt in the water changes with the tides. Sometimes the water is mostly freshwater, and sometimes it is mixed with saltwater. Various plant species live in this environment and provide a habitat for other organisms.

To successfully live in an estuary, a plant species must have an adaptation that allows it to —

A produce large amounts of food

B absorb large amounts of water

C store excess gases

D filter excess salt

d

The flow of energy in some Australian food chains is modeled in the energy pyramid below. Based on the model, which consumers would receive the greatest amount of energy captured by the producers in their food chains?

F Wedge-tailed eagles

G Chuditch

H Ring-tailed opossums

J Eucalyptus trees

h

The satellite image below shows a ship channel between South Padre Island and Boca Chica beach in South Texas.

Sand is sometimes removed from the ship channel through a process called dredging to make it easier for ships to travel through. Recently sand from the bottom of the channel was moved to area beaches. Without this transfer of sand, what would most likely occur in this area in the future?

A The ship channel would become deeper, and the island would move west toward the mainland.

B The ship channel would become shallower, and the beach would become narrower.

C The ship channel would become narrower, and the island would become completely covered with water.

D The ship channel would become wider, and the island would sink into the Gulf of Mexico

b

A student is studying calcium, a highly reactive element that humans need for strong bones.Which characteristic of calcium is most closely related to its chemical reactivity?

F The 20 protons in each atom of calcium

G The density of calcium, which is 15. 4 g/cm³

H The atomic mass of calcium, which is 40.078 amu

J The 2 valence electrons in each atom of calcium

j

When a space shuttle was launched, the astronauts on board experienced an acceleration of 29.0 m/s². If one of the astronauts had a mass of 60.0 kg, what net force in newtons did the astronaut experience?

a 1800

b 0.48

c 1740

d 2.06

c

A scientist named Joseph Connell studied two species of barnacles on the shore of a Scottish island. In the area between the average tide and the neap high tide, he found that the population of Species A was smaller than that of Species B. He removed Species B from one area but left both Species A and B in a similar area. The graph below shows the results of this study.

Based on these data, which hypothesis was Connell most likely testing?

F The populations of both species of barnacles increase more in warm water than in cool water.

G Barnacles grow larger when they are isolated from other species.

H The two species of barnacles compete with each other for resources.

J The two species of barnacles are closely related to each other.

h

A model of a beryllium atom is shown below.

What types of particles are found in the cloud surrounding the atom’s nucleus?

A Positively charged particles and negatively charged particles

B Negatively charged particles only

C Neutral particles and positively charged particles

D Positively charged particles only

b

A student draws the model shown below.

Which of these best compares the conditions at Location X and Location Y?

F It is day at Location X and night at Location Y.

G It is winter at Location X and summer at Location Y.

H There are more hours of daylight at Location X than at Location Y.

J The moon is brighter when viewed from Location X than when viewed from Location Y.

h

Based on its chemical formula, which of the following substances is an organic compound?

A Urea CH₄N₂O

B Ammonium sulfide,(NH₄)₂S

C Silane, SiH₄

D Sodium chloride, NaCl

a

In the aquatic food web below, which two organisms have a predator-prey relationship?

F Shad and sturgeons

G Sturgeons and blue crabs

H Blue crabs and rangia clams

J Copepods and amphipods

h

The graph below shows distance over time.

Which of these situations could be represented by this graph?

A student walks 1.5 km to a friend’s house in 40 minutes. The two students then walk another 1.5 km to school in 20 minutes.

B A student walks 1.5 km to a friend’s house in 20 minutes. The two students then walk another 1.5 km to school in 40 minutes.

C A student walks 1.5 km to a friend’s house in 30 minutes. The two students then walk another 1.5 km to school in 30 minutes.

D A student walks 1.5 km to a friend’s house in 20 minutes. The two students then walk another 1.5 km to school in 60 minutes.

b

Some students used records from the U.S. Naval Observatory to make the table below of the percent of the moon that was visible on each night in January 2011.

Based on these data, what part of the lunar cycle occurred between January 5 and January 7?

F Waxing crescent moon

G Waning crescent moon

H Full moon

J New moon

f

In the chemical reaction shown above, the products are best classified as —

A two elements

B one element and one compound

C two compounds

D two compounds and one element

c

The diagram below shows a model of the movement of two tectonic plates. When the plates collide, one plate often moves below the other plate.

The rising magma that can result from this type of plate movement may produce —

F fossil layers

G volcanic islands

H deep-sea sediment

J seafloor spreading

g

A student uses a magnet to move a 0.025 kg metal ball. The magnet exerts a force of 5 N,which causes the ball to begin moving. What is the acceleration of the ball when it begins to move?

A 200 m/s²

B 0.125 m/s²

C 5 m/s²

D 5.025 m/s²

a

The diagram below shows four positions in Earth’s orbit around the sun.

The Northern Hemisphere experiences the beginning of spring when Earth is in —

F Position 1

G Position 2

H Position 3

J Position 4

h

When people run long distances, their muscles require increased amounts of oxygen. Which system is responsible for carrying this oxygen to the muscles?

A Nervous

B Respiratory

C Digestive

D Circulatory

d

The points labeled W and Y on the topographic map below show the campsites of two families.Each family hiked to the elevation on the map marked X. The arrows show the paths taken by both families.

What was the change in elevation, to the nearest ten meters, for the family that took the steepest path to Point X?

a 140 m

b 40 m

c 100 m

d 120 m

d

The chemical formula for sodium sulfate is Na₂SO₄. How many sulfur atoms are in the formula for sodium sulfate?

A 1

B 2

C 6

D 7

a

In 1838 botanist Matthias Schleiden determined that all plants are composed of cells. In 1839 anatomist Theodor Schwann proposed that all animals are composed of cells. In 1855 biologist Rudolph Virchow added to Schleiden’s and Schwann’s observations and proposed that all living things are composed of cells. Which statement is also part of Virchow’s cell theory?

F All cells have a cell wall.

G All cells arise from pre-existing cells.

H All cells are capable of photosynthesis.

J All cells can develop into any other type of cell.

g

What is the mass number of a potassium (K) atom that has 20 neutrons?

A 18

B 19

C 20

D 39

d

What is the difference between the velocity and the speed of an object?

F Velocity is the change in distance over time, while speed is the change in velocity overtime.

G Velocity has a direction associated with it, while speed has no specific direction.

H Velocity has no direction associated with it, while speed has a specific direction.

J Velocity is the change in speed over time, while speed is the change in distance over time.

g

The moon reflects different amounts of sunlight onto Earth at different times. This reflected sunlight is commonly called moonlight. The graph below shows the intensity of moonlight at different times in a lunar cycle.

c

Fish in a lake have to compete for space. Different fish have different optimal temperature ranges. The graph below shows the temperature ranges of four fish species.

At which temperature range will there be the most competition for space among these fish species?

F 5°C to 10°C

G 10°C to 15°C

H 15°C to 20°C

J 25°C to 30°C

j

Hurricanes and similar storm systems begin over oceans. The map below shows average surface temperatures of the oceans in the summer.

Based on the map, which area probably produced the most violent storm systems?

A Area 1

B Area 2

C Area 3

D Area 4

c

Some students were investigating the speed of a toy car they built. They performed two trials and recorded their data in the table below.

What was the average speed of the toy car during the two trials to the nearest tenth of a m/s?

a 4.0 m/s

b 1.4 m/s

c 2.8 m/s

d 5.0 m/s

b

A scientist performed four investigations using eight different liquids. In each investigation,the scientist combined two of the liquids under a fume hood and recorded observations in the table below.

In which investigation is it least likely that the liquids reacted chemically?

A 1

B 2

C 3

D 4

c

The types of small organisms that live on the bottom of streams can be good indicators of water pollution. The table below groups some organisms by their tolerance of pollution.'

A certain stream that was historically clear and clean has become increasingly polluted with fertilizer waste over the years. Which of these describes a likely result of this pollution?

F Mayflies that were previously abundant are no longer present in the stream.

G Stone flies and midges thrive and compete for the same food source.

H Large numbers of crayfish have suddenly died.

J Riffle beetles have become more abundant in the stream.

f

The diagram below shows a sled moving along a smooth, frictionless track.

In which sections of the track will the sled experience an unbalanced force?

A Sections 1 and 3

B Sections 2 and 3

C Sections 2 and 4

D Sections 3 and 4

c

Four students are asked to describe a nebula and a star. Their responses are shown in the table below.

Which student described these two celestial bodies correctly?

F Student 1

G Student 2

H Student 3

J Student 4

h

The masses of four vehicles and the net forces acting on them as they enter a highway are recorded in the table below.

Which vehicle has the greatest acceleration as it enters the highway?

A Sedan

B Coupe

C SUV

D Truck

b

Serotonin is a chemical substance that acts as a neurotransmitter. It helps relay messages in the human brain. The formula for one molecule of serotonin is shown below. C₁₀H₁₂N₂O. How many atoms in all are in a molecule of serotonin?

a 12

b 22

c 25

d 10

c

The table below shows the distances of three stars from the sun. Students were asked to make a model of the three stars and to include the sun and Earth in the model. They chose to use a scale of 1 meter : 1 light-year.

d

A student is studying the ways different elements are similar to one another. Diagrams of atoms from four different elements are shown below.

Which two atoms are of elements in the same group in the periodic table?

F Atom 1 and Atom 2

G Atom 1 and Atom 4

H Atom 2 and Atom 3

J Atom 3 and Atom 4

g

The African savanna is a grassland scattered with shrubs and small trees. Some of the organisms that live in the savanna are shown below.

Which two types of organisms have a producer-consumer relationship in this African savanna?

A Zebras and hyenas

B Hyenas and cheetahs

C Trees and elephants

D Fungi and dung beetles

c

Some students conducted a laboratory investigation to learn more about the physical properties of different elements. They observed four samples and recorded their observations in the table below.

Based on these observations, which sample is most likely a nonmetal?

F Sample 1

G Sample 2

H Sample 3

J Sample 4

f

Four students volunteered to help a librarian move containers of library materials. The graphs hows the amount of force used to lift the containers. The numbers in the bars show the mass of each container. The results for each student helper are shown in the table.

Based on this information, which student helper did not do any work on a container?

A Helper W

B Helper X

C Helper Y

D Helper Z

d

The hydra is a very small, simple animal that lives in water. Hydras reproduce asexually by budding, a process in which a bud breaks off an adult hydra and floats away.

Which of the following best describes a hydra bud?

F A hydra bud contains genetic material from its two parents.

G A hydra bud is genetically identical to the parent hydra.HA hydra bud has different mutations than the parent hydra.

J A hydra bud has half as much genetic material as the parent hydra.

g

An atom of which element is described by the data in the table?

A Radon (Rn)

B Cadmium (Cd)

C Rubidium (Rb)

D Astatine (At)

c

Which student correctly identified the geologic process that formed the Himalayan mountains?

F Student 1

G Student 2

H Student 3

J Student 4

f

The food webs below model relationships among the organisms in two ecosystems.

Which ecosystem would be more likely to survive if a disease killed the grasses?

A The forest ecosystem, because most of the animals can eat other organisms

B The grassland ecosystem, because several predators compete for food

C The forest ecosystem, because it has three top predators

D The grassland ecosystem, because it has many herbivores

a

The force causes the car to move at a constant speed of 3 m/s. What will happen if the force is changed to 35 N?

F The car will move at a constant speed of 13 m/s.

G The speed of the car will not change.

H The speed of the car will increase.

J The speed of the car will decrease to 1 m/s.

h

Some dairy farmers want to increase the amount of milk produced by their cows. How can the farmers use selective breeding to increase milk production?

A By increasing the age of the cows that are bred

B By choosing cows that are high milk producers

C By limiting the number of offspring per-cow

D By choosing cows that can produce milk after eating the most food

b

A balance and a graduated cylinder are used to determine the density of a mineral sample. The sample has a mass of 14.7 g and a volume of 2.2 cm³. What is the density of the mineral sample?
F 0.15 g/cm³

G 32 g/cm³

H 13 g/cm³

J 6.7 g/cm³

j

The pickup truck has a changing velocity because the pickup truck —

A can accelerate faster than the other two vehicles

B is traveling in the opposite direction from the other two vehicles

C is traveling on a curve in the road

D needs a large amount of force to move

c

The folded mountains in this model form at which type of plate boundary?

F Transform boundary

G Divergent boundary

H Subduction boundary

J Convergent boundary

j

A researcher wants to experiment with an element that reacts like phosphorus (P) but has a greater atomic mass. Which element should the researcher select for the experiment?

A Nitrogen(N)

B Sulfur(S)

C Arsenic (As)

D Silicon(Si)

c

Wild Soay sheep live in a cold environment on a small Scottish island. The sheep used to be large because they gained extra weight during the summers in order to survive the harsh winters. A recent change in the island’s climate has caused grass to be available for a longer period each year, so survival conditions for the sheep have become less challenging.

Researchers who study these sheep have most likely observed a decrease in the wild Soay’s —

F size

G life expectancy

H reproduction rates

J body temperature

f

Which of the following situations shows work being done?

A A student is sitting in a chair and holding both boxes.

B A student is holding the large box 1 m above the floor.

C A student is standing and holding the small box.

D A student is lifting the small box 0.5 m from the floor to a table.

d

Which of the following best summarizes the effect of saltwater on these plant species?

F Species 1 can sprout only in fresh water, and Species 2 can sprout only in saltwater.

G Both species can sprout in freshwater and saltwater, but Species 2 can sprout in a higher salt concentration than Species 1.

H Both species need salt in their water, but Species 2 needs more salt than Species 1.

J Species 1 can sprout only in water with a low salt concentration, but Species 2 is not affected by the salt concentration.

g

The Milky Way galaxy is described as a disk of stars orbiting a central point on the disk. Which of these best explains why people on Earth cannot see the entire shape of the Milky Way?

A Earth is a part of this galaxy.

B Many more stars exist outside the galaxy.

C The stars in the center of the galaxy are extremely small.

D The center of the galaxy consists of a dense cluster of stars.

a

Which of these best explains the student’s data?

F The speed of the cart decreases as the cart rolls down the ramp because of friction between the cart and the ramp.

G The speed of the cart increases as the cart rolls down the ramp because the force acting on the cart is greater than the force of gravity.

H The speed of the cart increases as the car trolls down the ramp because the forces acting on the cart are unbalanced

J The speed of the cart decreases as the cart rolls down the ramp because the forces acting on the cart are balanced.

h

An atom of which element is represented by this model?

A Boron(B)

B Carbon(C)

C Neon (Ne)

D Sodium (Na)

a

How will this crater most likely change overtime?

F It will get deeper as it fills with water.

G It will rise up like a volcanic crater.

H It will become less deep as the rim erodes.

J It will widen as it fills with lava.

h

Certain species of whiptail lizards have only female individuals and no males. These lizards reproduce asexually. What is one disadvantage of asexual reproduction for these lizards?

A A new population can be established by a single individual in a relatively short period of time.

B All the members of a population are genetically very similar and less able to survive environmental changes.

C They are smaller than lizards that reproduce sexually.

D They are more likely to develop a variety of tail lengths.

b

Two cars with different masses travel at the same speed down a hill toward a stop sign. What will happen when both cars apply brakes at the same time to stop?

F The car with the smaller mass will require less force to stop than the car with the larger mass.

G The car with the larger mass will maintain its velocity while traveling down the hill.

H The car with the smaller mass will take longer to stop than the car with the larger mass.

J The car with the larger mass will have less inertia than the car with the smaller mass.

f

Which of the following best describes an electron?

A It has no charge and about the same mass as a proton.

B It has a negative charge and much less mass than a proton.

C It has a positive charge and much more mass than a neutron.

D It has a negative charge and about the same mass as a neutron.

b

Which of these locations on Earth experiences the least change in the number of day light hours throughout the year?

F Equator

G North Pole

H Tropic of Cancer

J Tropic of Capricorn

f

How many organisms in this food web eat only producers?

A 1

B 2

C 3

D 4

c

A scientist spilled a few drops of dilute hydrochloric acid (HCl) on a lab table. For safety purposes, the scientist sprinkled some baking soda (NaHCO3) onto the spill. Which observation would provide the best evidence that a chemical reaction occurred?

F The baking soda and hydrochloric acid combined, and bubbles formed.

G The baking soda absorbed the hydrochloric acid.

H Some of the baking soda dissolved in the hydrochloric acid.

J The hydrochloric acid evaporated, leaving only the baking soda.

f

At which of these positions does the ball have both the greatest kinetic energy and the least potential energy?

A Position1

B Position2

C Position3

D Position4

b

Which information could a student determine from only the chemical formula of a protein?

F The color of the protein

G The number of molecules in each sequence that makes up a protein

H The physical arrangement of atoms in the structure of the protein

J The number of atoms of each element in the protein

j

What is one condition that is necessary for a hurricane to form?

A Warm ocean water

B A strong cold front

C Cold ocean water

D A strong warm front

a

Which toy car had the greatest applied force?

F 1

G 2

H 3

J 4

j

d

Based on the identification key, which type of tree is this sample from?

F Ginkgo

G Honey locust

H Horse chestnut

J Black maple

h

A student builds a model based on this diagram. The student uses foam balls to represent the moon and Earth and a flashlight to represent the sun. The student should shine the flash light on the model of Earth from Position—

A 1

B 2

C 3

D 4

d

An object will continue moving in a straight line unless it is acted on by an unbalanced force. Which of the following best explains Earth’s motion?

F There is no unbalanced force acting on Earth because space is empty and nothing touches Earth.

G The gravitational force pulling Earth toward the sun is equal and opposite to the force pulling the sun toward Earth, so there is no unbalanced force acting on Earth.

H The sun moves in an elliptical orbit around Earth, and the sun’s gravity pulls Earth along.

J Earth moves in an elliptical orbit around the sun because the gravitational force of the sun attracts Earth.

j

Which organisms in the food web shown above compete for the same food source in this environment?

A Grasshoppers and snakes

B Hawks and frogs

C Frogs and snakes

D Decomposers and grasses

c

A car travels at a constant speed of 15 m/s for 2 minutes. The car increases its speed from 15 to 25 m/s during the next minute and then travels at a constant speed of 25 m/s for 2 more minutes. Which of the following graphs best represents the car’s motion during this 5-minute period?

f

While exploring a lake in Argentina, Laguna del Diamante (Diamond Lake),scientists found rocks covered with mats made of photosynthetic microbes. Flamingos in the area filter the nutrient-rich microbes by pumping the lake water through their bill. What is the relation ship between the photosynthetic microbes and the flamingos in the Laguna del Diamante ecosystem?

A The microbes are parasites, and the flamingos are hosts.

B The microbes are carnivores, and the flamingos are predators.

C The microbes are herbivores, and the flamingos are carnivores.

D The microbes are producers, and the flamingos are consumers.

d

A student walks 2 km in 30 minutes. What is the student’s average speed in km/h?

A 4

B 2

C 8

D 1

a

Hay is made up of organic compounds. What are the main elements in many organic compounds?

A Helium, carbon, sodium

B Sodium, hydrogen, nitrogen

C Carbon, hydrogen, oxygen

D Radon, oxygen, helium

c

Some students take care of a vegetable garden. When it is time to plant in the spring, the students leave part of the garden empty in order to observe ecological succession. Which of these will most likely occur first?

F Development of top soil

G Growth of weeds and grasses

H Growth of trees and shrubs

J Development of a stream

g

When trying to identify an unknown element, a scientist determines what other elements the unknown element reacts with chemically. Which property of the unknown element determines the other elements it reacts with?

A The total number of neutrons in the unknown element

B The total number of particles in the nucleus of the unknown element

C The number of protons in the nucleus of the unknown element

D The number of valence electrons in the unknown element

d

Plants use energy from sunlight, water, and carbon dioxide to produce sugar. Which structure is found only in plant cells and helps plants capture energy from sunlight?

F Vacuole

G Nucleus

H Chloroplast

J Cell membrane

h

Which geologic feature is most likely to form at a mid-ocean ridge?

A Peninsula

B Volcano

C Delta

D Plateau

b

Some students measure the acceleration of a wheeled cart being acted on by varying forces. The students record their data in the table shown above. According to the data table, how much force is acting on the cart when the students measure an acceleration of 2.6 m/s²?

F 13N

G 7N

H 8N

J 12N

f

A student is asked to identify an element that is a pale-yellow brittle solid and does not conduct electricity. At which location in this periodic table would the element most likely be found?

A 1

B 2

C 3

D 4

c

A 1240

B 1600

C 400

D 360

d

d

An atom has 25 protons, 30 neutrons, and 25 electrons. What is the charge of the atom’s nucleus?

F +25

G +30

H −25

J −30

f

The sudden movement of the plates is caused by —

A the mass of the plates

B the weight of the plates

C unbalanced forces

D gravitational force

c

The movement of colored water through the gravel best models —

F condensation of water vapor

G surface runoff of precipitation

H conservation of water

J pollution of ground water

j

The Couch’s spade foot is adapted to a certain type of environment. Which of these resources is most likely scarce in this environment?

A Soil

B Sunlight

C Water

D Oxygen

c

How many atoms of oxygen are in a molecule of glucose(C₆H₁₂O₆)?

A 6

B 12

C 18

D 24

a

Baleen whales eat zooplankton by taking a large amount of water into their mouth. These whales use special structures in their mouth to separate zoo plankton from the water. Because baleen whales eat zooplankton, they are classified as—

A producers

B predators

C parasites

D hosts

b

A student keeps a record of the phases of the moon for one month. On the first night of the student’s observations, the full moon is visible in the sky. After the full moon, which of these phases will the student observe next?

F Waxing crescent moon

G Waxing gibbous moon

H Waning crescent moon

J Waning gibbous moon

j

The characteristics of a particular organism are listed below.

Characteristics of an Organism

• Is multicellular
• Is autotrophic
• Has cell walls
• Has cell nuclei
• Can reproduce sexually or asexually In which kingdom should this organism be classified?

A Fungi

B Eubacteria

C Plantae

D Animalia

c

j

Which of these observations of Barnard’s Star is most likely accurate?

A Barnard’s Star is less bright than the sun, has a surface temperature below 3,800 K, and is red.

B Barnard’s Star is less bright than the sun, has a surface temperature above 3,800 K, and is red.

C Barnard’s Star is brighter than the sun, has a surface temperature below 5,300 K, and is yellow.

D Barnard’s Star is brighter than the sun, has a surface temperature above 5,300 K, and is yellow.

a

Some scientists studying aquatic plants notice that flooding often leads to a decrease in the rate of photosynthesis among aquatic plants. Flooding causes more sediment to be suspended in the water. The increased sediment concentration decreases the amount of light that reaches the plants. Why does a decreased rate of photosynthesis lead to a decrease in a plant population?

F Less water is available for absorption.

G Less tissue is available for plant growth.

H Less energy is available for reproduction.

J Less soil is available for leaf development.

h

Earth would not have seasons if it —

A no longer tilted on its axis

B stopped rotating on its axis

C took an additional month to orbit the sun

D revolved around the sun in the opposite direction

a

The student observed that the temperature changed from 25°C to 23°C when the solutions were combined and that a white substance rapidly formed and settled to the bottom of the container. What most likely happened to produce these results?

F One of the original compounds came out of solution.

G The solutions reacted chemically.

H Some of the water froze into ice crystals.

J Rapid evaporation of water occurred, leaving a solid.

g

Why does Earth get more energy from the sun than from all the other stars in the universe combined?

A The sun is much larger than the other stars.

B The sun is much hotter than the other stars.

C The sun is much more dense than the other stars.

D The sun is much closer than the other stars.

d

How will the boat be affected if it enters a part of the river where the current is moving south at 2m/s?

F The boat will move slower.

G The boat will move faster.

H The boat will stop.

J The boat will move to the west.

f