ASVAB General Science Practice Test 2020 (PDF)

ASVAB General Science Practice Test 2020 (PDF) sample question papers for Armed Services Vocational Aptitude Battery exam and Armed Forces Qualification Test (AFQT) preparation.

General Science (GS) tests the ability to answer questions on a variety of science topics drawn from courses taught in most high schools. The life science items cover botany, zoology, anatomy and physiology, and ecology. The earth and space science items are based on astronomy, geology, meteorology, and oceanography. The physical science items measure force and motion mechanics, energy, fluids, atomic structure, and chemistry.

Actual Exam Content in GS Part

Test Type

Number of Question

ASVAB Paper-and-Pencil 25-items
CAT-ASVAB Test 16-items

ASVAB General Science Practice Test 2020

The following ASVAB General Science (GS) Practice Test is only for reference purpose, it’s not an actual exam test questions. You can download our free ASVAB GS Practice Test in PDF (printable and editable), this will help you to make better ASVAB Test Prep offline. You can also use these files (PDF, DOC) as worksheets.

Name of the Test ASVAB Practice Test
ASVAB Stands for Armed Services Vocational Aptitude Battery
AFQT Stands for Armed Forces Qualification Test
Test Type Sample Multiple Choice Test
Total Questions 25 (twenty-five)
Answers and Explanation Available
Printable and Editable PDF Available
Subject Name General Science (GS)
Purpose Measures knowledge of life science, earth and space science, and physical science.

Q1. The basic unit of life is

  • A. the cell.
  • B. DNA.
  • C. the carbon molecule.
  • D. oxygen.
View Correct Answer
 Answer: A

Although DNA, carbon, and oxygen are important to life, the basic unit of life is the cell. Choice A is the correct answer.  

Q2. When a plant undergoes photosynthesis, one of the by-products is

  • A. carbon dioxide.
  • B. light.
  • C. ozone.
  • D. oxygen.
View Correct Answer
 Answer: D

During the process of photosynthesis, a plant uses carbon dioxide and water. Through the interaction of chlorophyll and light, glucose (a sugar) and oxygen are created. Carbon dioxide (choice A) is not a by-product of photosynthesis, but rather the raw material used by the plant, and light (choice B) acts to initiate the process of photosynthesis as it interacts with chlorophyll. Ozone is found high in the atmosphere and is not created by plants. Choice D, oxygen, is the correct answer.  

Q3. Why is the nucleus so important to a living cell?

  • A. It controls the production and elimination of cell waste.
  • B. It controls most of the activities of the cell.
  • C. It controls photosynthesis.
  • D. It uses oxygen to make carbon dioxide.
View Correct Answer
 Answer: B

The nucleus is important because it controls most of the activities of the cell. Choice B is the correct answer  

Q4. Which of the following do not have organelles?

  • A. Muscle cells
  • B. Protozoa
  • C. Nerve cells
  • D. Bacteria
View Correct Answer
 Answer: D

Muscle cells (choice A) and nerve cells (choice C) all have organelles. Protozoa (choice B), which are one-celled organisms, also have organelles. Bacteria (choice D) do not. Choice D is the correct answer.  

Q5. Which of the following is not an example of a fruit?

  • A. Raspberries
  • B. Sunflower seeds
  • C. Corn
  • D. Potato
View Correct Answer
 Answer: D

A fruit is a ripened ovary or group of ovaries containing seeds. When the ovary is fertilized, the seeds develop and the ovary enlarges, forming the fruit. Examples of fruits are peanuts, sunflower seeds, barley, walnuts, tomatoes, grapes, oranges, apples, raspberries, cucumbers, quash, corn, eggplant, and strawberries. A potato does not contain or form seeds, so choice D is the correct answer.  

Q6. Which of the following terms can be used to describe a bird?

  • A. Invertebrate, omnivore
  • B. Vertebrate, warm-blooded
  • C. Endoskeleton, cold-blooded
  • D. Crustacean, endoskeleton
View Correct Answer
 Answer: B

Birds are vertebrates that are warm-blooded. Choice B is the correct answer.  

Q7. Why are decomposers important to an ecosystem?

  • A. They make nutrients available for plants to use.
  • B. They create soil for farming.
  • C. They stabilize the soil.
  • D. They enhance the habitat with specialized particles important to life.
View Correct Answer
 Answer: A

Decomposers break down tissue and release nutrients and carbon dioxide into the ecosystem. Choice A is the correct answer.  

Q8. Which of the following is the part of the skeletal system that protects the spinal cord?

  • A. Marrow
  • B. Cartilage
  • C. Ligaments
  • D. Vertebrae
View Correct Answer
 Answer: D

Marrow (choice A) is the soft tissue within the bone and does not protect the spinal cord. Cartilage (choice B) is a smooth, slippery covering on  the ends of bones that acts as a shock absorber. Its purpose is not to protect the spinal cord. Ligaments (choice C) are one of the ways in which bones are joined and move together. They do not protect the spinal cord. The vertebrae, found in your back, do indeed protect the spinal cord. Choice D is the correct answer.  

Q9. A bruise on your skin is the result of which of the following?

  • A. Excess strain on the muscle
  • B. Broken capillaries
  • C. Overactive sweat glands
  • D. Swelling
View Correct Answer
 Answer: B

A bruise on your skin may cause a bit of swelling (choice D), but the bruise is not related to your sweat glands (choice C). Excess strain on
your muscles (choice A) may cause some discomfort, but that is not likely to break your capillaries. Bruising is caused by some traumatic
event that breaks the capillaries. Choice B is the correct answer.  

Q10. The function that moves food from one part of the digestive system to another is called

  • A. respiration.
  • B. digestion.
  • C. mechanical decomposition.
  • D. peristalsis.
View Correct Answer
 Answer: D

Peristalsis is the muscular contraction of the digestive system that moves food from one part of the system to the next. For example, peristalsis is responsible for moving food from the stomach to the large intestine.  

Q11. Which of the following words are all associated with the nervous system?

  • A. Nephrons, urethra, bladder
  • B. Antigens, T cells, cilia
  • C. Hypothalamus, pons, cortex
  • D. Lymph nodes, spleen, tonsils
View Correct Answer
 Answer: C

The hypothalamus, pons, and cortex (choice C) are all parts of the brain and thus of the nervous system. Nephrons, urethra, and bladder (choice A) are part of the excretory system. Antigens, T cells, and cilia (choice B) are all part of the immune system. Lymph nodes, spleen, and tonsils (choice D) are part of the lymphatic system. Choice C is the correct answer.  

Q12. Which of the following is the name for the space between two nerve cells where an electric charge transmits information?

  • A. Nerve cell gap
  • B. Synapse
  • C. Axon
  • D. Dendrite
View Correct Answer
 Answer: B

Dendrites (choice D) and axons (choice C) are parts of the nerve cell. The nerve cell gap (choice A) is not the correct answer because it is not related to the nervous system. The space between two nerve cells where an electric charge transmits information is called a synapse. Choice B is the correct answer.  

Q13. Which of the following states is likely to have the greatest biodiversity?

  • A. North Dakota
  • B. Illinois
  • C. Nebraska
  • D. Florida
View Correct Answer
 Answer: D

Biodiversity tends to increase with warmer climate. Florida is the warmest state of those listed, so choice D is the correct answer  

Q14. Which of the following best represents what happens to ultraviolet radiation from the sun when it reaches Earth’s atmosphere?

  • A. It changes into chlorofluorocarbons.
  • B. Some of it is absorbed by the ozone layer.
  • C. All of it reaches Earth’s surface.
  • D. It is deflected back into space.
View Correct Answer
 Answer: B

Ultraviolet light is absorbed, at least in part, by the ozone layer in the atmosphere. Some of it passes through to Earth’s surface. With the thinning of the ozone layer as a result of the introduction of chlorofluorocarbons into the atmosphere, more ultraviolet light is reaching Earth’s surface, with possibly damaging effects on humans. Choice B is the correct answer.  

Q15. Which of the following properties of a sound wave affects how loud or soft the sound is?

  • A. Crest
  • B. Trough
  • C. Frequency
  • D. Amplitude
View Correct Answer
 Answer: D

The amplitude of a sound wave is responsible for the loudness of the sound. Choice D is the correct answer.  

Q16. The major force causing sea-floor spreading, continental drift, and the collision of continental plates is

  • A. subduction of Earth’s core.
  • B. creation of oceanic ridges.
  • C. compression of continents.
  • D. convection currents in the mantle.
View Correct Answer
 Answer: D

All the alternatives have something to do with sea-floor spreading, but only one is the cause. Subduction (choice A) is a downward force or movement that is a result of sea-floor spreading, not the cause. The same can be said for creation of the ridges (choice B) and for the compression of continents (choice C). They are both results, not causes. All these features are produced by the convection currents in the mantle, which cause the uprising and subduction of the crust. Choice D is the correct answer.  

Q17. When two tectonic plates converge and one rises above the other, which of the following are likely to form?

  • A. Volcanoes
  • B. Hot spots
  • C. Tsunamis
  • D. Rifts
View Correct Answer
 Answer: A

A rift (choice D) is a valley in the ocean floor formed by tectonic plates that are separating. A tsunami (choice C) is a wall of water that can overwhelm a shoreline. It is created when an earthquake creates an ocean wave. Hot spots (choice B) are undersea fissures that are spouting magma from the sea floor. The Hawaiian Islands have been and continue to be created from hot spots. When two tectonic plates converge and one rises above the other, it is common to find areas that experience earthquakes and volcanic activity. Choice A, volcanoes, is the correct answer.  

Q18. Breaking waves or breakers that occur near the shoreline are caused by which of the following conditions?

  • A. Earthquakes that occur far out in the ocean
  • B. Friction between the wave trough and the ocean bottom
  • C. The expansion of the wavelength of the wave
  • D. Increasing tidal forces
View Correct Answer
 Answer: B

When a wave is created in the ocean by persistent surface winds, the wave moves in the direction of the winds. When that wave approaches land, it moves through shallow water and the trough (bottom) of the wave starts to scrape the ocean bottom. The scraping causes friction, and that makes the trough of the wave move more slowly than the crest (top) of the wave. Eventually, the crest just topples over, creating a breaker. Choice B is the correct answer. 

Q19. How long does it take for Earth to make one revolution around the sun?

  • A. 1 year
  • B. 1 month
  • C. 1 week
  • D. 1 day
View Correct Answer
 Answer: A

The definition of a year is the time it takes for Earth to make one revolution around the sun. Choice A, 1 year, is the correct answer.  

Q20. An eclipse of the sun occurs under which of the following conditions?

  • A. Earth is between the sun and the moon.
  • B. Earth is rotating faster than the moon.
  • C. Earth, the sun, and the moon are perpendicular to each other.
  • D. The moon is between the sun and Earth.
View Correct Answer
 Answer: D

A solar eclipse is created when the moon blocks the light from the sun from reaching Earth by casting a shadow on Earth’s surface. The shadow covers only a very small area, so a total solar eclipse is visible only on a limited part of Earth’s surface at any one time. The shadow has two parts, a darker part called the umbra, where a total eclipse occurs, and a lighter part called the penumbra, where a partial eclipse can be seen. In order for a solar eclipse to occur, the moon has to be between the sun and Earth. Choice D is the correct answer.  

Q21. Earth’s greenhouse effect is caused by which of the following conditions?

  • A. Changing rainfall patterns from global warming
  • B. Heat from the sun that is trapped by atmospheric gases
  • C. The increase in the thickness of the ozone layer
  • D. The number of plants in tropical rainforests trapping CO2
View Correct Answer
 Answer: B

When solar radiation reaches Earth’s atmosphere, the radiation is either reflected, absorbed by Earth’s atmosphere, or trapped by Earth’s atmosphere. When it is trapped by the atmosphere, it causes the atmosphere and Earth’s surface to heat up. Choice B is the correct answer.  

Q22. Which of the following can hold the most moisture?

  • A. Cold air
  • B. Moving air
  • C. Stable air
  • D. Warm air
View Correct Answer
 Answer: D

Warm air can hold more moisture than cold air. Air masses formed over the tropical oceans can hold significant amounts of moisture, while air masses formed over cold oceans or land masses are generally drier. Whether the air is moving or stable does not much affect the humidity in the air. Choice D, warm air, is the correct answer.  

Q23. When a prevailing wind reaches a mountain range, what happens to the air?

  • A. It is blocked and starts to move backward.
  • B. It rises and cools, causing condensation.
  • C. It expands and heats, resulting in rain.
  • D. It expands and heats, resulting in a dry, desertlike area.
View Correct Answer
 Answer: B

When a prevailing wind containing moisture reaches a mountain range, it rises and cools, causing condensation in the form of rain or snow. The side of the mountain range on which this happens is called the windward side. Much of the moisture in the air is deposited on the windward side of a mountain range. When the air reaches the tops of the mountains, it starts to spill down the other side. As it descends, it heats up. The side of the mountain range on which this happens is called the leeward side. Often you will find deserts on the leeward side of a mountain range. The climate is definitely drier on the leeward side. Choice B is the correct answer. 

Q24. The process of erosion is linked to the formation of which of the following types of rocks?

  • A. Igneous
  • B. Extrusive
  • C. Sedimentary
  • D. Metamorphic
View Correct Answer
 Answer: C

Igneous rocks (choice A) are formed from molten material that eventually cools. Extrusive rocks (choice B) are igneous rocks that have formed on or above the Earth’s surface. Metamorphic rocks (choice D) are created by high temperature and pressure. Sedimentary rocks (choice C) are formed by rock that has been broken up into pieces and cemented together. The pieces can be somewhat large, as in a conglomerate, or small, such as in shale or limestone. Choice C is the correct answer.  

Q25. Scientists believe that the universe is expanding because of which of the following indicators?

  • A. The difference in time it takes for light from various stars to reach us
  • B. The red shift in the spectra of stars
  • C. The difference in chemical composition of various stars
  • D. The explosion of supernovas
View Correct Answer
 Answer: B

When objects move away from a viewer, the light waves they produce lengthen, shifting toward the red end of the spectrum. Scientists have observed that light from distant stars shifts toward the red end of the spectrum. This supports the conclusion that the universe is expanding. Choice B is the correct answer.  

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