concentrationof 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

the shaking of the ground caused by a sudden release of energy in Earth’s crust

an integrated unit of a biological community, its physical environment, and interactions

a substance that cannot be reduced to a simpler substance by chemical means

a quantity that describes the capacity to do work; a source of usable power

a pyramidal diagram that compares the amount of energy available at each position, or level, in the feeding order

a change of energy from one form to another (e.g., mechanical to electrical, solar to electrical)

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

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

the wearing away of Earth’s surface by the breakdown and transportation of rock and soil

the process by which a liquid is converted to its vapor phase by heating the liquid

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

transfer of energy through various stages as a result of feeding patterns of a series of organisms

the interconnected feeding relationships in a food chain found in a particular place and time

a quality that tends to produce movement or acceleration of a body in the direction of its application; a push or pull

a whole or part of a plant or animal that has been preserved in sedimentary rock

a force that opposes the relative motion of two material surfaces in contact with one another

the pivot point of a lever

a large collection of stars, gases, and dust that are part of the universe (e.g., the Milky Way galaxy) bound together by gravitational forces

one of the fundamental states of matter in which the molecules do not have a fixed volume or shape

a force of attraction between two masses

the observed effect of the force of gravitation

a place in an ecosystem where an organism normally lives

a form of energy resulting from the temperature difference between a system and its surroundings

an animal that feeds on plants

a type of rock that forms from molten or partly molten material that cools and hardens

a type of simple machine; a slanted surface that makes it easier to move a mass from a lower point to a higher point

the property of a body, due to its mass, that causes it to resist any change in its motion unless overcome by a force

aprocedure that is carried out in order to observe a response caused by a stimulus; not a complete experiment

the energy possessed by a body because of its motion

a type of simple machine; consists of a rigid bar that pivots about a fulcrum, used to transmit and enhance power or motion

the entire sequence of events in an organism’s growth and development

electromagnetic radiation that lies within the visible range

one of the fundamental states of matter with a definite volume but no definite shape

the amount of matter an object contains

a solid, liquid, or gas that possesses inertia and is capable of occupying space

a type of rock that forms from existing rock because of extreme changes caused by heat, pressure, or chemical environments

relating to an object too small to be visible without the use of a microscope

the product of a thorough blending of two or more substances, not chemically combined

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

a resource that can only be replenished over millions of years

a structure containing different tissues that are organized to carry out a specific function of the body (e.g., heart, lungs, brain, etc.)

a chemical process by which plants trap light energy to convert carbon dioxide and water into carbohydrates (sugars)

a reaction; a change in matter from one form to another, without forming new substances

a large body in space that orbits a star and does not produce light of its own

any alteration of the natural environment producing a condition harmful to living organisms; may occur naturally or as a result of human activities

a group of organisms of the same species living in a specific geographical area

the energy an object has because of its position or structure; stored energy

an organism that preys on and consumes animals; usually an animal

an organism caught or hunted for food by another organism

an organism that makes its own food from the environment; usually a green plant

unicellular organisms belonging to the kingdom Protista

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

the bouncing off or turning back of light, sound, or heat from a surface

a change in the direction of a wave that occurs as it passes from one medium to another of different density

a resource that is replaced or restored, as it is used, by natural processes in a reasonable amount of time

any material that can be used to satisfy a need

a plan of inquiry that uses science process skills as tools to gather, organize, analyze, and communicate information

rock formed from layers of sediment that overlay and squeeze together or are chemically combined

a star and all the planets and other bodies that orbit it; the region in space where these bodies move

having a definite shape and a definite volume; one of the fundamental states of matter

a mixture of two or more substances uniformly dispersed throughout a single phase

a large, gaseous, self-luminous body held together by gravity and powered by thermonuclear reactions

the closest star to Earth and the center of our solar system

a set of objects, organisms, or different parts acting to form a whole

similar cells acting to perform a specific function; four basic types of tissue are muscle, connective, nerve, and epidermal

the surface, shape, and composition of a land area

the total sum of all matter and energy that exists

a vent or fissure in Earth’s surface through which magma and its associated materials are expelled; generally a mountain-like structure

a measure of the amount of space an object takes up; also the loudness of a sound or signal

the path water takes as it is being cycled through the environment, including condensation, evaporation, and precipitation

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

a type of simple machine; a circular frame or disk revolving around a central axis