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Contemporary's GED Science
Robert Mitchell

GED Practice Test


The Science Test consists of multiple-choice questions intended to measure general concepts in science. The questions are based on short readings that often include a graph, chart, or figure. Study the information given and then answer the question(s) following it. Refer to the information as often as necessary in answering the questions.

You should try to complete the 25 questions on this test in 40 minutes or less. Work carefully, but do not spend too much time on any one question. Be sure you answer every question.

When you have finished the test, click on Submit Answers to receive feedback and results. You may also choose to e-mail your results to your instructor. To determine your GED standard score, click on GED Score in the sidebar on the left-hand side of your screen.

Questions 1 and 2 refer to the following information.

A group of agricultural researchers conducted an experiment to study the growth rates of plants at various temperatures. In their laboratory, they divided primrose, cucumber, and corn plants into a number of different groups. During the experiment, they kept the different groups of primrose plants at different but constant temperatures for twenty-four hours every day. They did the same for the corn and cucumber plants. The graph shows the growth rates that they recorded for the different groups of plants.
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According to the graph, at what temperature did primroses grow best?

A)40 °F
B)50 °F
C)60 °F
D)70 °F
E)80 °F

Judging from the data in the graph, what sort of climate would favor the growth of cucumbers?

A)cold nights, cold days
B)cold nights, warm days
C)very warm nights, very warm days
D)warm, rainy days
E)warm nights, cool days

Question 3 refers to the following information.

The lightweight-materials content of the average car manufactured in the United States has increased sharply since the mid-1970s. The data shown in the graph are for an average passenger car produced by one major manufacturer and are typical of all U.S. automakers. Lightweight materials are shown in blue. Heavy materials are indicated in yellow.
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Which of the following statements is a conclusion about cars made during the 1980s that can be drawn from the graph?

A)Cars in the 1980s became increasingly expensive.
B)Cars made in the 1980s were more difficult to handle than those in the 1970s.
C)Cars made during the 1980s required more fuel per mile than those in the 1970s.
D)Cars made during the 1980s weighed less than cars made during the 1970s.
E)Cars in the 1980s could carry fewer and fewer passengers.

Questions 4 and 5 refer to the following information.

In 1861 someone found a 150-million-year-old fossil of a pigeon-sized bird that resembled a dinosaur with feathers. The ancient creature had a brain and a scaly head like a dinosaur but the wishbone, wings, and feathers of a bird. Scientists named the animal Archaeopteryx and assumed it was the ancestor from which all modern birds evolved.

For many years, scientists agreed that dinosaurs existed before birds. Although many dinosaurs were large and heavy, some were very small. The small creatures ran quickly on two long back legs and grasped food with short forelegs. Scientists hypothesized that over a span of 60 million years, these dinosaurs evolved into birds. Their short forelegs became wings. Their scales became feathers.

In August 1986 two newly discovered incomplete fossil skeletons caused scientists to change their hypothesis. The newly found fossils have characteristics of modern birds that Archaeopteryx lacked, but they are 75 million years older than Archaeopteryx. A large brain case, wide eye sockets, and a breastbone anchoring the muscles used in flight are hallmarks of a modern bird. The fossils found in 1986 show these characteristics; Archaeopteryx does not. If the identification of the new fossils is correct, it appears now that birds evolved much earlier than scientists had believed.


Which of the following statements BEST summarizes the information above?

A)New fossil data suggest that birds did not develop from dinosaurs but were present at the same time as the earliest dinosaurs.
B)Modern birds are very different from their earliest ancestors and are still developing new traits.
C)Fossils are the only way scientists can study creatures that lived on earth more than 60 million years ago.
D)Birds and dinosaurs evolved from reptiles more than 150 million years ago.
E)Newly found fossils prove that birds developed from larger species of dinosaurs than scientists had originally thought.

Below are five items that would interest a researcher studying fossils of the earliest birds.
A. how old the fossils are
B. how large the birds grew
C. how far the birds could fly
D. how the birds resembled dinosaurs
E. what the birds ate
Which points of information could the researcher establish through scientific analysis?

A)A only
B)A and B only
C)A and E only
D)D and E only
E)A, B, and D only

Questions 6 and 7 refer to the following weather map.

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For which area of the country is snow predicted?

B)Rocky Mountains
C)Central Plains
E)Mid-Atlantic Coast

When two fronts meet, thunderstorms often result. Which area of the country might have thunderstorms within the next few days?

C)Central Plains

Questions 8 and 9 refer to the following table.

Sound Level Chart

DecibelBelType of SoundTimes as Loud as 0 Decibels
00The least sound heard by a normal human ear1
101The rustle of leaves in a light breeze10
202An average whisper 4 feet away from hearer100
303Broadcasting studio when no program is in progress1,000
404Night noises in a city10,000
505Average residence1000,000
606Normal conversation at 3 feet1,000,000
707An accounting office10,000,000
808A noisy city street100,000,000
909A moderate dance club1,000,000,000
10010A blender10,000,000,000
11011A pneumatic drill100,000,000,000
12012A jet engine1,000,000,000,000


A person wants to make a tape recording of the sounds of daily surroundings. The tape will include leaves rustling in a summer breeze, whispered conversation, printers and copy machines in a business office, and sounds of a busy downtown area during lunch hour. Through what minimum decibel range must the recording equipment be sensitive?


A scientist could use the chart to obtain all EXCEPT which of the following information?

A)the relationship of a decibel to a bel
B)how much louder 40 decibels is than 20 decibels
C)the sound level associated with different settings
D)the intensity level at which sounds become uncomfortable
E)how many times greater a sound at 9 bels is than a sound at 0 decibels

Question 10 refers to the following information.

Normally, immune responses help protect an organism's body. However, some immune responses, such as allergies, do not seem to be protective. Allergies can occur in some people when they eat certain foods, receive certain drugs, or come into contact with dust or pollens.

Allergies stem from several processes in the body. In some individuals, the body produces allergy antibodies that stick to white blood cells called mast cells. When a person comes into contact with a substance to which he or she is allergic, that substance reacts with the allergy antibodies. The mast cells release histamine as a result of this reaction. Histamine is responsible for the runny nose, itchy eyes, and difficult breathing associated with allergy.

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Based on the information above, what must happen for an allergic reaction to occur?
A)The allergy antibody must attach itself to the mast cell.
B)Pollen in the air must trigger the production of disease-carrying antibodies.
C)The allergy antibody must attack histamine.
D)The allergy-causing substance must attack histamine.
E)The body must be unable to produce antibodies to fight off diseases.

Questions 11 through 13 refer to the following information.

Boats float and rocks sink in a lake. These characteristics are due to the density of boats, rocks, and water. Density is the weight of a substance divided by the volume it occupies. Different substances may have different densities. If equal volumes of two liquids have different weights, the heavier liquid has a greater density. A liquid that is less dense than water will float on water, and a liquid that is more dense than water will sink.


If water, cooking oil, and corn syrup are very carefully poured into a glass, one at a time, three distinct layers will form, as shown in the diagram.

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What will happen if a drop of corn syrup is added to the glass containing the three liquid layers of water, oil, and corn syrup?

A)The drop of corn syrup will float on the top layer.
B)The drop will pass through the oil and water and mix with the corn-syrup layer.
C)The drop will be trapped between the water and oil layers.
D)The drop will mix with the oil layer.
E)The drop will sink to the very bottom of the glass.

Blood is made primarily of red blood cells, white blood cells, and a liquid called plasma. Medical laboratories often need to separate blood into its three main parts. This separation can be easily done because each part has a different density. Blood is carefully added to a test tube containing a medium called Ficoll-Hypaque, as shown in A.

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After A is processed, the blood separates into the three parts shown in B. Which of the following statements about the densities of the three parts is correct?

A)Plasma is the densest component.
B)White blood cells are more dense than red blood cells.
C)Red blood cells are denser than either white blood cells or plasma.
D)All blood cells are equally dense.
E)Red cells are less dense than whole blood.

Many scientists believe that the ocean floors float on top of Earth’s mantle—a thick layer of very dense rock—and that the continents float on top of the ocean floors.

Which of the following statements describes a discovery that best explains the observation that the continents rise above the ocean floors?

A)The continents are smaller than the ocean floors, so the continents are less dense.
B)The ocean floors are held down by the density of the water on top of them.
C)The continents consist of granite, which is less dense than the rock that forms the ocean floors.
D)The mantle is made of very dense rock.
E)The material in the earth’s mantle is more dense than the rock in the ocean floors.

Questions 14 and 15 refer to the following information.

A person visiting Mexico was frightened when a snake crossed his path and then turned toward him. The man grabbed a stick and clubbed the snake. When he was sure the reptile was dead, he sat down and examined it. He made the following observations. The rings around the body formed the following pattern: black, red, black, yellow; black, red, black, yellow. The scales were smooth, all about the same size, and cycloid in shape. No other markings were seen.

Later, he found a book about snakes and used the following key to identify the snake he had killed.

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Which of the following statements best summarizes the information on the key?

A)Smooth scales of similar size and shape are characteristic of blind snakes.
B)The size of the scales on a snake’s head distinguishes colubrids from true boas.
C)Colored rings and their arrangement separate elapids from blind snakes
D)Snakes are best distinguished by their coloration, their scales, and the presence of a pit.
E)Pit vipers have a deep pit between their nostrils and eyes, but colubrids and true boas do not.

What assumption did the man most likely make when he killed the snake?

A)Most snakes feed on rats and mice.
B)Snakes are dangerous.
C)Snakes feed very infrequently.
D)Some types of nonpoisonous snakes very closely resemble poisonous ones.
E)Some snakes that appear ferocious are actually quite harmless.

Question 16 refers to the following graph.

Two cars, A and B, were tested to determine how they accelerate in second gear. The results are shown below.
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Which of the following CANNOT be determined from the information in the graph?
A)engine RPM when the test ended
B)engine RPM at zero seconds
C)how long it took each engine to reach 6,000 RPM after the test started
D)final speed of each car
E)speed of each car at four seconds

Questions 17 and 18 refer to the following information.

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Five physical properties of waves are defined below.
A. amplitude—the height of a wave, directly related to the energy carried by that wave
B. frequency—the number of waves that pass a point each second
C. speed—how fast a light wave moves
D. vibration—repeated movement back and forth or up and down
E. wavelength—the distance from one wave crest to the next


As a dimmer switch is turned, the light in a lamp becomes brighter. How are the light waves emitted by the light changing?

They are increasing in


What property of a light wave determines the time it takes sunlight to travel the 93 million miles from the Sun to Earth?


Question 19 is based on the following information.

Cockroaches and owls are most active at night. Robins wake with the first light of day. Bean plants lift and lower their leaves at a regular time each day. Such biological cycles occur approximately every 24 hours and are called circadian rhythms. They seem to be linked to the cycle of the sun. The sunlight resets the cycles each day to keep them synchronized with the environment. However, when plants or animals are kept under conditions of constant light, their biological activities continue to cycle, though they may speed up or slow down.

The biological nature of these rhythms is not understood, but some facts are known. For example, there are usually several circadian rhythms going on at the same time. The rhythms stem from specific regions in the body. These regions are called clocks, and one clock can control several rhythms. A clock is located in the eyes of squids and snails, and in the brains of lizards, birds, and mammals.

As many as four circadian rhythms have been identified in algae. If fighting conditions change, the clock also changes, but all four rhythms maintain their time relationship to each other. The following diagram shows three of the four circadian rhythms of algae.

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Biological clocks also exist in humans. Sleeping, waking, and eating are mainly circadian rhythms. Less apparent rhythms include changes in body temperature and in the release of certain hormones at particular times each day.


Which of the following statements BEST summarizes the information given in the graph about the algae?

A)Several distinct processes in the algae are controlled by circadian rhythms.
B)Many biological processes occur in the algae.
C)Photosynthesis in algae controls many of the organism’s other processes.
D)Photosynthesis occurs once a day in algae.
E)The circadian rhythms in algae will reset if the biological clock is disturbed.

A food chain is a group or organisms related to each other in their feeding habits. One organism is eaten by a second one, which in turn is fed upon by a third one. The food chain starts with energy from the Sun. As each organism grows and is eaten, only about 10 percent of the Sun's energy is transferred at each step. People who live in areas of the world where food is scarce eat very little meat and depend on grains and other plants. Based on the ideas presented, which of the following statements best supports such eating habits?

A)It is easier to grow plants than raise animals.
B)Plants taste better than meat from animals.
C)Plants take up less space than grazing animals.
D)More than 90 percent of the energy in plants never reaches people who eat the animals raised on the plants.
E)Plants store energy in sugar molecules.

Questions 21 and 22 are based on the following graph.

The graph shows how two anticancer drugs compare in their ability to kill tumor cells. The killing effect of the drugs on both tumor cells and normal cells is measured at several doses of each drug.
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Which one of the following statements CANNOT be verified from the graph?

A)the percentage of tumor cells killed by drug A at a dose of 30 mg/ml
B)whether normal cells are killed by certain doses of either drug
C)whether any dose of drug B will kill both normal and tumor cells
D)which drug kills more tumor cells at a certain dosage
E)how many kinds of tumor cells each drug will kill

A physician discovers that he has cancer. His family urges him to begin drug therapy. The physician knows that cancer drugs act by killing cells that are dividing. He is reluctant to undergo treatment. His family does not understand why.

Which one of the following statements indicates that his family may not fully understand how cancer drugs work?

A)Drug therapy works against some types of cancers.
B)Many drugs used in cancer therapy cause cells to die when they divide.
C)The drugs kill cancer cells because they rarely stop dividing.
D)Cancer drugs kill all dividing cells, including normal ones.
E)A cell that divides often is more likely to be killed by the cancer drug.

Questions 23 through 25 refer to the following information.

The time line below shows the occurrence of earthquakes in Kaoiki, a small area located between two very active volcanoes in Hawaii. The black dots mark the dates on which earthquakes that originated in Kaoiki occurred. The white circle indicates an earthquake that occurred somewhere in the area, but not enough evidence was available to conclude that the quake originated in Kaoiki.
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According to the time line, earthquakes occur at very regular intervals. In which of the following years, covered by the time line above, would an earthquake also have been expected at Kaoike, Hawaii?


Which of the following statements represents a hypothesis rather than a fact?

A)An earthquake occurred in Kaoiki in 1941.
B)Five earthquakes occurred during a 43-year period.
C)The location of the 1930 earthquake in Hawaii is not definitely known.
D)An earthquake should have occurred at Kaoiki about 1920.
E)Six earthquakes have been recorded in or near Kaoiki.

Which of the following events follows a predictable pattern in a way similar to earthquakes in Kaoike, Hawaii?

A)Mount St. Helens erupted in Washington in 1980.
B)Tornadoes are common in the Midwest but not the Northeast.
C)The number of sunspots peaks about every eleven years.
D)Heavy snowfall is more characteristic of northern latitudes.
E)Mudslides can be a problem in California.