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FCAT Science Glossary
- Adaptation- a characteristic of an organism that increases its chance of survival in its environment
- Atmosphere- the layers of gas that surround Earth, other planets, or stars
- Atom- the smallest unit of a chemical element that can still retain the properties of that element
- Axis- the imaginary line on which an object rotates (e.g., Earth’s axis runs through Earth between the North Pole and the South Pole); an imaginary straight line that runs through a body; a reference to the line in a coordinate system or graph
- Carnivore- an animal or plant that consumes or obtains nutrients from animals
- Change of state- a physical change that occurs when matter changes to another state (i.e., liquid, gas, or solid)
- Chemical change- a reaction or a change in a substance produced by chemical means that results in producing a different chemical
- Community- all the populations of organisms belonging to different species and sharing the same geographical area
- Compound- a substance made up of a combination of two or more elements held together by chemical bonds that cannot be separated by physical means; has properties unlike those of the elements that make up the compound
- Condensation- the process of changing from a gas (i.e., water vapor) to a liquid (i.e., dew); the act of making more dense or compact
- Conservation- controlled use and/or maintenance of natural resources; various efforts to preserve or protect natural resources
- Constellation- a star pattern identified and named as a definite group; usually thought of as forming certain shapes or figures in a specific region of the sky
- Consumer- an organism that feeds on other organisms for food
- Decomposer- any organism that feeds or obtains nutrients by breaking down organic matter from dead organisms
- Density- concentration of matter of an object; number of individuals in the same species that live in a given area; the mass per unit volume of a substance in a given area
- Deposition- layering matter in a natural process
- Earthquake- the shaking of the ground caused by a sudden release of energy in Earth’s crust
- Ecosystem - an integrated unit of a biological community, its physical environment, and interactions
- Element- a substance that cannot be reduced to a simpler substance by chemical means
- Energy- a quantity that describes the capacity to do work; a source of usable power
- Energy pyramid- a pyramidal diagram that compares the amount of energy available at each position, or level, in the feeding order
- Energy transfer- a change of energy from one form to another (e.g., mechanical to electrical, solar to electrical)
- Environment- the sum of conditions affecting an organism, including all living and nonliving things in an area, such as plants, animals, water, soil, weather, landforms, and air
- Equator- an imaginary circle around Earth’s surface located between the poles and a plane perpendicular to its axis of rotation that divides it into the Northern and Southern Hemispheres
- Erosion - the wearing away of Earth’s surface by the breakdown and transportation of rock and soil
- Evaporation- the process by which a liquid is converted to its vapor phase by heating the liquid
- Experiment- a procedure that is carried out and repeated under controlled conditions in order to discover, demonstrate, or test a hypothesis; includes all components of the scientific method
- Food chain- transfer of energy through various stages as a result of feeding patterns of a series of organisms.
- Food web (food cycle)- the interconnected feeding relationships in a food chain found in a particular place and time
- Force- a quality that tends to produce movement or acceleration of a body in the direction of its application; a push or pull
- Fossil- a whole or part of a plant or animal that has been preserved in sedimentary rock
- Friction- a force that opposes the relative motion of two material surfaces in contact with one another
- Fulcrum- the pivot point of a lever
- Galaxy- a large collection of stars, gases, and dust that are part of the universe (e.g., the Milky Way galaxy) bound together by gravitational force
- Gas- one of the fundamental states of matter in which the molecules do not have a fixed volume or shape
- Gravitation- a force of attraction between two masses
- Gravity- the observed effect of the force of gravitation
- Habitat- a place in an ecosystem where an organism normally lives
- Heat- a form of energy resulting from the temperature difference between a system and its surroundings
- Herbivore- an animal that feeds on plants
- Igneous rock- a type of rock that forms from molten or partly molten material that cools and hardens
- Inclined plane- a type of simple machine; a slanted surface that makes it easier to move a mass from a lower point to a higher point
- Inertia- the property of a body, due to its mass, that causes it to resist any change in its motion unless overcome by a force
- Investigation- a procedure that is carried out in order to observe a response caused by a stimulus; not a complete experiment
- Kinetic energy- the energy possessed by a body because of its motion
- Lever- a type of simple machine; consists of a rigid bar that pivots about a fulcrum, used to transmit and enhance power or motion
- Life cycle- the entire sequence of events in an organism’s growth and development
- Light- electromagnetic radiation that lies within the visible range
- Liquid- one of the fundamental states of matter with a definite volume but no definite shape
- Magnetic- having the property of attracting iron and certain other materials by virtue of a surrounding field of force
- Mass- the amount of matter an object contains
- Matter- a solid, liquid, or gas that possesses inertia and is capable of occupying space
- Metamorphic rock- a type of rock that forms from existing rock because of extreme changes caused by heat, pressure, or chemical environments
- Microscopic- relating to an object too small to be visible without the use of a microscope
- Mixture- the product of a thorough blending of two or more substances, not chemically combined
- Moon- a natural satellite that revolves around a planet
- Moon phase- a phrase that indicates the fraction of the Moon’s disc that is illuminated (as seen from Earth); the eight moon phases (in order): new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent
- Nonrenewable resource- a resource that can only be replenished over millions of years
- Organ- a structure containing different tissues that are organized to carry out a specific function of the body (e.g., heart, lungs, brain, etc.)
- Organism- any living plant, animal, or fungus that maintains various vital processes necessary for life
- Photosynthesis- a chemical process by which plants trap light energy to convert carbon dioxide and water into carbohydrates (sugars)
- Physical change- a reaction; a change in matter from one form to another, without forming new substances
- Planet- a large body in space that orbits a star and does not produce light of its own.
- Pollution- any alteration of the natural environment producing a condition harmful to living organisms; may occur naturally or as a result of human activities.
- Population- a group of organisms of the same species living in a specific geographical area.
- Potential energy- the energy an object has because of its position or structure; stored energy.
- Predator- an organism that preys on and consumes animals; usually an animal
- Prey- an organism caught or hunted for food by another organism.
- Producer- an organism that makes its own food from the environment; usually a green plant.
- Protist- unicellular organisms belonging to the kingdom Protista
- Pulley- a type of simple machine; a circular lever, usually a wheel with a groove where a rope can be placed and used to change the direction of a force
- Reflection - the bouncing off or turning back of light, sound, or heat from a surface
- Refraction- a change in the direction of a wave that occurs as it passes from one medium to another of different density
- Renewable resource- a resource that is replaced or restored, as it is used, by natural processes in a reasonable amount of time.
- Resource - any material that can be used to satisfy a need.
- Scientific method- a plan of inquiry that uses science process skills as tools to gather, organize, analyze, and communicate information.
- Sedimentary rock- rock formed from layers of sediment that overlay and squeeze together or are chemically combined.
- Solar system-a star and all the planets and other bodies that orbit it; the region in space where these bodies move
- Solid -having a definite shape and a definite volume; one of the fundamental states of matter
- Solution- a mixture of two or more substances uniformly dispersed throughout a single phase
- Star- a large, gaseous, self-luminous body held together by gravity and powered by thermonuclear reactions
- Sun- the closest star to Earth and the center of our solar system
- System-a set of objects, organisms, or different parts acting to form a whole
- Tissue-similar cells acting to perform a specific function; four basic types of tissue are muscle, connective, nerve, and epidermal
- Topography-the surface, shape, and composition of a land area
- universe-the total sum of all matter and energy that exists
- Volcano-a vent or fissure in Earth's surface through which magma and its associated materials are expelled; generally a mountain-like structure
- Volume-a measure of the amount of space an object takes up; also the loudness of a sound or signal
- Water cycle- the path water takes as it is being cycled through the environment, including condensation, evaporation, and precipitation
- Weathering-the natural processes that break down and change rock into soil, sand, and other materials; differs from erosion in that no transportation of those materials takes place
- Wheel and axle-a type of simple machine; a circular frame or disk revolving around a central axis
- Abiotic- an environmental factor not associated with the activities of living organisms
- Acceleration- rate of change in velocity, usually expressed in meters per second; involves an increase or decrease in speed and/or a change in direction
- Air resistance- force of air on moving objects
- Allele- any of two or more alternate forms of a gene that an organism may have for a particular trait
- Amplitude-in any periodic function (e.g., a wave) the maximum absolute variation of the function
- Asexual reproduction- a form of reproduction in which new individuals are formed without the involvement of gametes
- Biodiversity- the existence of a wide range of different species in a given area or specific period of time
- Biotic- factors in an environment relating to, caused by, or produced by living organisms
- Calorie- unit of energy; the amount of heat needed to raise one gram of water one degree Celsius at standard atmospheric pressure
- Chemical weathering- the breakdown and alteration of rocks at or near Earth's surface as a result of chemical processes
- Circuit- an interconnection of electrical elements forming a complete path for the flow of current
- Conduction- the transmission of heat through a medium and without the motion of the medium
- Conservation of energy- a fundamental principle stating energy cannot be created nor destroyed but only changed from one form to another
- Convection- heat transfer in a gas or liquid by the circulation of currents from one region to another
- Crest- the peak or highest point on a wave.
- Crust- outermost layer of Earth covering the mantle
- Dependent variable- factor being measured or observed in an experiment
- Deposition- the process by which sediment is carried by forces (e.g., wind, rain, or water currents) and left in a certain area
- Diffraction- the change in direction of a wave caused by passing by an obstacle or traveling through an opening
- Dominance - tendency of certain (dominant) alleles to mask the expression of their corresponding (recessive) alleles
- Ecosystem- an ecological community, together with its environment, functioning as a unit
- Efficiency- the relative effectiveness of a system or device determined by comparing input and output
- Electromagnetic radiation- the emission and propagation of the entire range of electromagnetic spectrum including: gamma rays, x-rays, ultraviolet radiation, visible light, microwaves, and radio waves
- Electron- a stable elementary particle that is negatively charged and orbits the nucleus of an atom
- Entropy- a measure of randomness or disorder of a closed system
- Erosion- a combination of natural processes in which materials from Earth's surface are loosened, dissolved, or worn away and transported from one place to another
- Fossil fuels- the remains of animal or plant life from past geologic ages that are now in a form suitable for use as a fuel (e.g., oil, coal, or natural gas)
- Frequency- the number of cycles or waves per unit time
- Gene- a specific part of a chromosome or sequence of DNA that determines a particular feature or characteristic in an organism
- Heterozygous- cell or organism that has two different alleles for a particular trait.
- Homozygous- cell or organism that has identical rather than different alleles for a particular trait
- Independent variable-the factor that is changed in an experiment in order to study changes in the dependent variable.
- Inertia - the property of an object, due to its mass, by which it resists any change in its position unless overcome by force
- Magnetic field- the region where magnetic force exists around magnets or electric currents
- Mass - the amount of matter an object contains
- Meiosis- the process of nuclear division in cells during which the number of chromosomes is reduced by half
- Mitosis - a process of nuclear division in eukaryotic cells during which the nucleus of a cell divides into two nuclei, each with the same number of chromosomes
- Neap tide- a twice-monthly tide of minimal range that occurs when the Sun, Moon, and Earth are at right angles to each other, thus decreasing the total tidal force exerted on Earth
- Neutral- a particle, object, or system that lacks a net charge
- Neutron- a subatomic particle having zero charge, found in the nucleus of an atom
- Nucleus- the center region of an atom where protons and neutrons are located; also a cell structure that contains the cell's genetic material
- Ocean basin- a depression on the surface of Earth occupied by water
- Plate tectonics- theory of global dynamics in which Earth's crust is divided into a smaller number of large, rigid plates whose movements cause seismic activity along their borders
- Potential energy- energy stored in an object due to the object's configuration and position
- Pressure- the force exerted per unit area
- Prism- a piece of glass with polished plane surfaces that disperses a beam of white light into its component colors
- Proton- a subatomic particle having a positive charge and which is found in the nucleus of an atom
- Punnett square- a graphic checkboard used to determine results from a particular genetic cross
- Radiation - emission of energy in the form of rays or waves
- Recessive- an allele for a trait that will be masked unless the organism is homozygous for this trait
- Screw- a type of simple machine that consists of an inclined plane wrapped around a cylinder
- Sexual reproduction- reproduction involving the union of gametes producing an offspring with traits from both parents
- Spectroscope- an instrument that uses a prism to separate and catalog light wavelengths
- Speed- amount of distance traveled divided by time taken; the time-rate at which any physical process takes place
- Spring tide- the tide of increased range that occurs twice monthly at the new and full phases of the Moon
- Thermal energy- internal energy found by adding the kinetic energy of particles making up a substance
- Tropism- the motion of an organism or part of an organism toward or away from an external stimulus
- Trough - the lowest point on a wave
- Variable- an event, condition, or factor that can be changed or controlled in order to study or test a hypothesis in a scientific experiment
- Velocity- the time-rate at which a body changes its position; defined as displacement divided by the time of travel.
- Vibration- a repetitive movement around an equilibrium point
- Virus-a noncellular, disease-causing particle that uses the genetic material from its host to reproduce
- Wavelength- the distance between crests of a wave
- Wedge-a type of simple machine that consists of an inclined plane used to separate two objects
- Wheel and axle-a type of simple machine that consists of a rod driven through the center of a cylinder that is allowed to rotate freely, yielding a mechanical advantage equal to the cylinder's diameter.
- Accuracy - the extent to which a measurement is in proximity to the standard or expected value
- Acid- a substance that increases the H* concentration when added to a water solution
- Activation energy - the least amount of energy required to start a particular chemical reaction
- Adaptation- a particular development, behavior, or physiological change in a population of organisms, in response to changes in the populations
- Amino acids- an organic molecule containing an amino (-NH2) and a carboxyl (-COOH) group from which proteins are synthesized
- Aqueous- a solution containing water
- Astronomical unit- the average distance from Earth to the Sun, approximately 150 million kilometers
- Atomic number- the number of protons in an atom's nucleus; the atomic number determines an element's placement on the periodic table
- Base - a substance that increases the "OH" concentration of a solution; a proton acceptor
- Biome- a complex biotic community characterized by the interaction of living organisms and climatic factors
- Catalyst- a substance that speeds up or slows down the rate of a reaction without being consumed or altered
- Centrifugal-the motion away from center or axis
- Centripetal force- the force on an object required to keep this object on a circular path, pulling toward the center of the circle
- Compound - a substance made up of at least two different elements held together by chemical bonds that can only be broken down into elements by chemical processes
- Concentration- the relative amount of a particular substance, a solute, or mixture
- Conservation of mass- the principle that mass cannot be created or destroyed; also conservation of matter
- Convergent boundary- area where two tectonic plates collide
- covalent bond- a chemical bond between two atoms of the same or different elements in which each atom shares an electron
- Diffraction - the bending of a wave around an obstruction
- DNA- a nucleic acid that carries genetic material; present in all cellular organisms
- Electromagnet- a magnet consisting of a coil of wire wrapped around a core that becomes strongly magnetized when current flows through the coil producing a magnetic field
- Electromagnetic waves- waves generated by the oscillation of a charged particle and characterized by periodic variations of electric and magnetic fields
- Fault- a rock fracture along which movement or displacement of Earth's crust has taken place
- First law of thermodynamics- a law that states the internal energy in a system remains constant and the change in thermal energy of a system is equal to the work done on the system
- Genotype- the sum total of the genetic information contained in an organism
- Half-life- the amount of time required for half of an original sample of radioactive material to decay or undergo radioactive transformation
- Heat of fusion- the amount of heat energy required to convert a unit mass of substance from a solid to a liquid through melting at a constant temperature and pressure
- Heat of vaporization- the amount of heat energy needed to change a unit mass of substance from a liquid to a gas at its boiling point
- Indicator- a chemical compound that changes color depending on the pH of the solution or other chemical change.
- Isotope- the form of an element with the same number of protons but a different number of neutrons
- Kelvin-fundamental SI unit of temperature where zero degrees Kelvin is equal to absolute zero (One degree Kelvin equals one degree Celsius.)
- Mass number -the total number of protons and neutrons in a nucleus
- Membrane-a thin layer of tissue that surrounds or lines a cell, a group of cells, or a cavity; any barrier separating two fluids
- Mid-ocean ridge-a continuous, seismic mountain range extending across the floor of the world's major oceans; area where two oceanic plates are moving away from each other; area where new crustal material may be released
- Molecule- the smallest unit of matter of a substance that retains all the physical and chemical properties of that substance; consists of a single atom or a group of atoms bonded together
- Momentum- a vector quantity that is the product of an object's mass and velocity; the general effect of ongoing motion
- Mutation- the process by which a gene undergoes a change in DNA sequence or a structural change
- Natural selection- the theory stating every organism displays slight variations from other organisms of its kind, and the struggle for limited natural resources results in individuals with certain natural variations adapted to their specific environments
- Niche- the unique position occupied by a particular species in terms of the area it inhabits and the function it performs within the community
- Nuclear fission- the process by which an atomic nucleus splits into two or more large fragments of comparable mass, simultaneously producing additional neutrons and vast amounts of energy
- Nuclear fusion- the process by which two lighter atomic nuclei combine at extremely high temperatures to form a heavier nucleus and release vast amounts of energy.
- Permeability- the capability of a porous substance or membrane to allow a fluid or gas to enter it; the measure or degree to which a substance can be penetrated by a liquid or gas
- PH - a symbol for the measure of the acidity or alkalinity of a solution
- Phenotype- the appearance or other observable characteristic of an organism resulting from the interaction of its genetic makeup and its environment
- Precision- the degree of accuracy or exactness of a measurement or tool
- Product- a substance or compound resulting from a chemical reaction
- Protein- a biological macromolecule composed of one or more chains of amino acids
- Rate of reaction - the speed at which reactants are consumed and products are produced in a given reaction
- Reactant- any substance or molecule that participates in a chemical reaction
- Rift valley - a long, narrow valley in Earth's crust where two continental plates are separating or between two faults
- RNA- a single-stranded nucleic acid consisting of a phosphate group and one of four nitrogenous bases that encodes information needed to synthesize proteins
- Second law of thermodynamics- a law that states all natural processes proceed in a preferred direction (e.g., heat flows from high temperature regions to low temperature regions)
- Solar mass - the quantity equal to the mass of the Sun
- Solubility- the ability or tendency of one substance to dissolve in another at a given temperature and pressure
- Species- a group of organisms of common ancestry able to reproduce only among themselves and usually geographically distinct.
- Stimulus -a condition that produces a response
- Succession- the progressive replacement, on a single site, of one type of community by another
- Vector - a physical quantity with both a magnitude and direction
- Velocity- the time rate at which a body changes its position vector; quantity whose magnitude is expressed in units of distance over time