TAKS April 2006 Gr 8 Science Online Test

DIRECTIONS
Read the question and choose the best answer. Then mark the circle next to the letter for the answer you have chosen.

1A student finishes an experiment and is left with three empty beakers that held liquids during the experiment. The best lab practice is to —

Aleave the beakers exactly as they are for the next student

Bturn the beakers upside down to drain in the sink

Cwash the beakers and air-dry them on a rack

Dtake the beakers directly to a rack to dry

2The photographs above show how a change in climate is affecting the size of Grinnell Glacier in Glacier National Park. Which of the following best explains the change in the glacier between 1910 and 1997?

FHigher average temperatures

GHigher frequency of earthquakes

HHigher total precipitation

JHigher rates of wind erosion

3A grassland community is pictured above. Grasses are considered —

Asecondary consumers

Bprimary consumers

Cdecomposers

Dproducers

4Which of the following processes helps the body maintain chemical balance?

FTears washing away dust from the eyes

GRib bones protecting internal organs

HHair growing faster in winter months

JCells using sugar in the blood

5Heavy rains in an aquifer’s recharge zone cause rivers and streams to flood. How will this most likely affect the aquifer?

AThe total water volume will increase.

BThe outflow from natural springs will decrease.

CThe water level in the aquifer will decrease.

DThe rate of water use by humans will increase.

6Which of the following best represents stored potential energy?

FAir leaking from a flat tire

GStress built up in a rock fault

HHeat given off by a forest fire

JWater flowing through a hose

7The scale drawings above show two catfish collected from a river. What is the difference in the actual body lengths of these catfish?

A3 cm

B9 cm

C12 cm

D24 cm

8Which of these is an example of a chemical reaction?

FA pot of water boiling

GAn iron nail rusting

HCorn being ground

JSugar dissolving in tea

9Which of the following shows how the plant above would grow if the pot were knocked on its side and left for several weeks?

11The single-celled organisms shown above live in water. What is the main function of the structures identified by the arrows?

AAbsorbing water

BRemoving wastes

CHelping with motion

DGetting food

12The transfer of carbon that results from burning fossil fuels will most likely affect Earth in the future by —

Fraising the average global temperature

Greducing evaporation rates of ocean water

Hdecreasing the total mass of plant life

Jmaking air transparent to ultraviolet light

13An experiment is being done to determine how light affects the growth of three different types of pea plants. Peas of each type are planted in several cups, and the cups are labeled X, Y, or Z to show the type of pea planted in each. Some cups are set in each of three locations to receive different amounts of light. Which of the following best shows how the plants should be arranged for the experiment?

14Which set of equipment would be used to measure the boiling point of a liquid?

FBalance, thermometer, and stopwatch

GTest tube, hot plate, and balance

HStopwatch, test tube, and microscope

JBeaker, hot plate, and thermometer

Use the information below and your knowledge of science to answer questions 15–18.

15Before the quarry was dug, the land contained more vegetation. What impact has this change most likely had on the local ecosystem?

ALarger predator populations

BA lower number of producers

CA greater number of herbivores

DA smaller amount of available carbon dioxide

16Both gypsum and limestone are found in the quarry. Limestone has about the same hardness as calcite. A mineral’s hardness can be determined from how easily it is scratched by another mineral. In a hardness test, what result will show the difference between gypsum and limestone?

FFluorite scratches limestone and gypsum.

GGypsum scratches talc.

HLimestone scratches talc.

JCalcite scratches gypsum.

17At the quarry, soil was removed to get to the rock layers underneath. Which part of the environment was probably least affected by this soil being removed?

AAir

BGroundwater

CRunoff water

DPlants

18Diesel fuel is used in the engines of the machines and trucks at the quarry. Which of these is the main energy transformation as the fuel is used by the engines?

FElectrical energy is converted to heat energy.

GHeat energy is converted to potential energy.

HElectrical energy is converted to kinetic energy.

JChemical energy is converted to kinetic energy.

20What is the volume of the liquid in the graduated cylinder?

Record your answer to the nearest milliliter in the space below.

(Your answer must be between 0 and 999.)

21Some data about the atmosphere of Mars are shown above. What conclusion can be made about the ability of humans to breathe Martian air?

ALife support will be needed because the percentage of oxygen is too low.

BIt will be impossible to breathe because the percentage of nitrogen is too low.

COxygen and nitrogen will make it possible for photosynthesis to produce food.

DHumans will be able to breathe the air because oxygen is present.

22The model above is set up to show how a lunar eclipse occurs. What is the greatest limitation of this model?

FThe lightbulb is standing straight up instead of tilted on an axis.

GComparative sizes and distances are inaccurate.

HThe shadow is being cast in the wrong direction.

JThe heat released is much less than that released by the sun.

23An engineer measured how much energy a new type of wind turbine generated in locations with different wind speeds. A graph of the results is shown above. What is the best inference about operating the wind turbine at a location with wind speeds ranging from 0 to 8 km/h?

AThe turbine can reduce a household’s electricity bill.

BThe air is too dense to turn the rotor blades of the turbine.

CThe wind moves too slowly to generate enough energy.

DAir pollution can be eliminated by using the turbine.

24A woman running in a marathon requires a constant supply of oxygen to her muscles. Which cells carry oxygen to muscle tissue?

FArtery cells

GRed blood cells

HNerve cells

JLung cells

25In the food web above, which of the following organisms feeds on the largest variety of different producers?

26Evidence suggests that dinosaurs became extinct when a large meteorite struck in the area of the Yucatán Peninsula. Scientists hypothesize that this enormous impact killed all the dinosaurs, even those on the other side of Earth, because the —

Fdebris thrown into the atmosphere blocked sunlight

Gheat flash from the impact immediately vaporized all life-forms

Himpact blasted the atmosphere surrounding Earth into space

Jintense heat completely boiled away the oceans

28In spring 2003 a natural rock outcropping in New Hampshire called the Old Man of the Mountain collapsed. Which of the following most likely loosened the rock and caused it to fall?

FHeat turning sedimentary rock into metamorphic rock

GWater freezing and thawing inside cracks in the rock

HVolcanic activity producing pressure at the rock’s base

JOxygen reacting with iron on the surface of the rock

29Which of the following is the most reasonable topographic map of the area shown in the picture?

30For rabbits, having long hair is an advantage over having short hair in environments with —

Fhigh levels of rain

Ga large number of competitors

Hlow temperatures

Jfew predators

31A foam dart is thrown toward a dartboard. The graph represents its motion. At about what speed is the dart traveling when it hits the dartboard, 7 meters from the starting point?

A6.3 m/s

B6.9 m/s

C7.2 m/s

D7.4 m/s

32The picture shows sand used to make a model of a galaxy. In the model, each grain of sand best represents —

Fa comet

Ga black hole

Han asteroid

Ja star

33The table above shows the number of protons in an atom of four different elements. According to the periodic table, which of these elements is a metal?

34The United States consumed about 19 million barrels of petroleum per day in 2000. This rate continues to increase. It is important to develop alternative sources of energy because petroleum —

Fwill eventually use up all the oxygen needed for human survival

Gis being spilled into the ocean faster than it is being used

Hfails to store solar energy and contains limited chemical energy

Jis a limited source of energy that is almost impossible to renew

35The table above shows that the more carbon atoms a compound has, the higher the compound’s boiling point. Based on the data in the table, a reasonable estimate of the boiling point of the next compound, C₇H₁₆, is —

A70°C

B99°C

C120°C

D142°C

36Which of the following is least affected by seasonal environmental conditions?

FThe pattern in a tiger’s fur

GThe dropping of tree leaves

HThe sprouting of acorns

JThe migration of gray whales

37The diagram shows the orbit of the moon around Earth. Between which two points will the moon appear to change from a new moon to a quarter moon?

AQ and R

BR and S

CS and T

DT and Q

38In the picture above, the rocks at the bases of the trees were separated from the cliff face by water freezing and thawing. Which process best describes the breaking of the rock?

FSoil erosion

GMountain building

HChemical weathering

JPhysical weathering

39Which molecule in the equation represents food energy made by plants?

ACarbon dioxide

BWater

CGlucose

DOxygen

40The graph shows the movement of a car over time. What is the car’s average speed?

F10 kilometers per hour

G15 kilometers per hour

H30 kilometers per hour

J60 kilometers per hour

41The picture above shows four varieties of the same species of grass that grow in a prairie ecosystem. Which variety has the best chance of surviving a long period of dry weather?

AVariety 1

BVariety 2

CVariety 3

DVariety 4

42One of the reactions involved in obtaining pure copper (Cu) from copper-containing rock is

Which of the following best describes the reaction?

FCopper atoms are used to produce more copper atoms.

GElements are rearranged into new substances.

HAtoms of other elements are turned into copper atoms.

JCompounds change phase from liquid to gas.

43Which of the following most promotes chemical weathering in limestone?

AFreezing water

BBlowing wind

CRunning water

DGrowing roots

44At which point on the roller coaster will the car have the greatest amount of kinetic energy?

45Glossy leaves are smooth and shiny. What percent of offspring from the cross shown above will have glossy leaves?

A0%

B25%

C50%

D100%

46Which energy transformation occurs when a match is lit?

FChemical energy to heat energy

GHeat energy to potential energy

HElectrical energy to heat energy

JKinetic energy to potential energy

47A cosmetics company markets bottles of nail polish remover with the label shown above. A consumer group concluded that the claim that the acetone is 100% pure is false. What is the most likely reason the consumer group reached this conclusion?

AThe acetone has probably dissolved some of the bottle.

BThe group has found that other claims by the company are false.

CThere are ingredients other than acetone in the nail polish remover.

DPure acetone is a flammable liquid, as stated on the label.

48During primary ecological succession, the initial formation of soil helps establish —

Fgrasses

Gmushrooms

Hshrubs

Jtrees

49Which diagram best represents the type of plate movement that results in mountain building?

50The picture shows the results of an experiment to investigate the effect of light on plant growth. The conclusion is weakened by the —

Fslope of the soil

Gcolor of the light source

Hflow of air into and out of the room

Jlength of time for the experiment

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