Armed Services Vocational Aptitude Battery (ASVAB) General Science (GS) Syllabus

General Science (GS) syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for General Science (GS) in Armed Services Vocational Aptitude Battery (ASVAB), not a summary of it.

1. 1

   Life Science and Biology

   4 topics

   • Cell Biology and Microscopy
     • Prokaryotic vs. eukaryotic cells
     • Organelles and their functions
     • Cell membrane and transport (osmosis, diffusion)
     • Mitosis and meiosis
   • Genetics and Heredity
     • DNA, RNA, and protein synthesis
     • Mendelian inheritance and Punnett squares
     • Dominant and recessive traits
     • Mutations and genetic disorders
   • Human Body Systems
     • Skeletal and muscular systems
     • Circulatory and respiratory systems
     • Digestive and excretory systems
     • Nervous and endocrine systems
   • Ecology and Classification
     • Food chains, food webs, and energy flow
     • Biomes and ecosystems
     • Taxonomy and the five/six kingdoms
     • Photosynthesis and cellular respiration
2. 2

   Earth and Space Science

   3 topics

   • Geology and Earth Structure
     • Earth's layers (crust, mantle, core)
     • Rock cycle and types of rocks
     • Plate tectonics, earthquakes, and volcanoes
     • Erosion and weathering
   • Meteorology and Weather
     • Atmosphere layers and composition
     • Weather fronts and cloud types
     • Water cycle and precipitation
   • Astronomy and the Solar System
     • Planets, moons, and the Sun
     • Phases of the Moon, eclipses, and tides
     • Stars, galaxies, and the universe
3. 3

   Chemistry

   3 topics

   • Atomic Structure and the Periodic Table
     • Protons, neutrons, and electrons
     • Elements, atomic number, and mass
     • Periodic table groups and periods
   • Matter and Its Properties
     • States of matter and phase changes
     • Physical vs. chemical properties
     • Mixtures, compounds, and solutions
   • Chemical Reactions and Bonding
     • Ionic and covalent bonds
     • Acids, bases, and the pH scale
     • Conservation of mass and balancing
4. 4

   Basic Physics

   4 topics

   • Forces and Motion
     • Newton's laws of motion
     • Speed, velocity, and acceleration
     • Gravity and friction
   • Energy and Work
     • Kinetic and potential energy
     • Work, power, and conservation of energy
     • Heat transfer (conduction, convection, radiation)
   • Waves, Sound, and Light
     • Wave properties (frequency, wavelength, amplitude)
     • Sound and the electromagnetic spectrum
     • Reflection and refraction
   • Electricity and Magnetism
     • Static and current electricity
     • Conductors and insulators
     • Magnets and electromagnetism

General Science (GS) flashcards for Armed Services Vocational Aptitude Battery (ASVAB)

25 of 51 cards from the General Science (GS) deck — real questions with worked answers.

1. What is the basic structural and functional unit of all living organisms?

   The cell. All living things are made of one or more cells, which are the smallest units capable of carrying out life processes.

2. What is the key structural difference between prokaryotic and eukaryotic cells?

   Prokaryotic cells (e.g., bacteria) lack a membrane-bound nucleus and organelles; eukaryotic cells (plants, animals, fungi, protists) have a true nucleus and membrane-bound organelles.

3. Which organelle is called the 'powerhouse of the cell' and why?

   The mitochondrion, because it carries out cellular respiration to produce ATP (energy) for the cell.

4. What two structures do plant cells have that animal cells lack?

   A rigid cell wall (made of cellulose) and chloroplasts (which contain chlorophyll for photosynthesis).

5. What is the function of a compound light microscope's objective and ocular (eyepiece) lenses, and how is total magnification calculated?

   Both lenses magnify the specimen. Total magnification = objective lens power x ocular lens power (e.g., 40x objective x 10x eyepiece = 400x).

6. What molecule carries genetic information, and what are its four nitrogenous bases?

   DNA carries genetic information. Its four bases are adenine (A), thymine (T), guanine (G), and cytosine (C); A pairs with T, and G pairs with C.

7. In genetics, what is the difference between a dominant and a recessive allele?

   A dominant allele is expressed even when only one copy is present; a recessive allele is expressed only when two copies are present (no dominant allele masks it).

8. What is the difference between genotype and phenotype?

   Genotype is the genetic makeup (allele combination, e.g., Bb); phenotype is the observable physical trait that results (e.g., brown eyes).

9. In a cross between two heterozygous parents (Bb x Bb), what is the expected phenotypic ratio?

   3:1 (three dominant phenotype to one recessive). The genotypic ratio is 1 BB : 2 Bb : 1 bb.

10. How many pairs of chromosomes do humans have, and which pair determines biological sex?

    23 pairs (46 total chromosomes). The 23rd pair determines sex: XX is female, XY is male.

11. What are the main functions of the human circulatory (cardiovascular) system?

    To transport oxygen, nutrients, hormones, and wastes throughout the body via the heart, blood, and blood vessels (arteries, veins, capillaries).

12. What is the role of the respiratory system, and where does gas exchange occur?

    It brings oxygen in and removes carbon dioxide. Gas exchange occurs in the alveoli (tiny air sacs) of the lungs.

13. Which body system includes the brain, spinal cord, and nerves, and what does it do?

    The nervous system. It senses stimuli, processes information, and controls/coordinates body responses.

14. What is the largest organ of the human body, and what system does it belong to?

    The skin, which belongs to the integumentary system. It protects against injury and infection, regulates temperature, and prevents water loss.

15. What is the function of the digestive system, and where does most nutrient absorption occur?

    It breaks down food into nutrients the body can absorb. Most nutrient absorption occurs in the small intestine.

16. In ecology, what is the difference between a producer, a consumer, and a decomposer?

    Producers (plants/algae) make their own food via photosynthesis; consumers eat other organisms; decomposers (bacteria/fungi) break down dead matter, recycling nutrients.

17. What are the levels of ecological organization from smallest to largest?

    Organism, population, community, ecosystem, biome, biosphere.

18. List the levels of taxonomic classification from broadest to most specific.

    Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

19. What is binomial nomenclature, and how is a species name written?

    A two-name naming system using Genus and species. The genus is capitalized, the species lowercase, and both are italicized (e.g., Homo sapiens).

20. What are the three main layers of the Earth from outside to inside?

    The crust (thin outer layer), the mantle (thick middle layer of semi-molten rock), and the core (outer liquid core and inner solid core, mostly iron and nickel).

21. What are the three main types of rock and how does each form?

    Igneous (from cooled magma/lava), sedimentary (from compacted/cemented sediments), and metamorphic (from existing rock changed by heat and pressure).

22. What is the theory of plate tectonics?

    Earth's lithosphere is broken into large plates that move over the mantle, causing earthquakes, volcanoes, mountain building, and continental drift at their boundaries.

23. What scale measures the magnitude (energy) of earthquakes, and what tool records them?

    The Richter scale (and the moment magnitude scale) measures earthquake magnitude; a seismograph records the seismic waves.

24. What are the four main layers of Earth's atmosphere from the ground up?

    Troposphere, stratosphere, mesosphere, and thermosphere. Weather occurs in the troposphere; the ozone layer is in the stratosphere.

25. What is the difference between weather and climate?

    Weather is the short-term state of the atmosphere at a place (temperature, precipitation, etc.); climate is the long-term average weather pattern of a region over many years.

See more General Science (GS) flashcards →

Planning General Science (GS) for Armed Services Vocational Aptitude Battery (ASVAB)

General Science (GS) (Armed Services Vocational Aptitude Battery (ASVAB)) FAQ