ASVAB General Science Practice Test 2024

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

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.  

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

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.  

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.  

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

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

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.  

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.  

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.  

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.  

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.  

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

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.  

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

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.  

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.  

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. 

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.  

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.  

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.  

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.  

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. 

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.  

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.