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199 Cards in this Set

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  • Back
earthquake a movement or trembling of the ground that is caused by a sudden release of energy when rocks along a fault move
Earth science the scientific study of Earth and the universe around it
Earth science
earthshine sunlight illuminating the moon after having been reflected off the Earth
eccentricity the degree of elongation of an elliptical orbit (symbol, e)
echinoderm a radially symmetrical marine invertebrate that has an endoskeleton, such as a starfish, a sea urchin, or a sea cucumber
echo a reflected sound wave
echolocation the process of using reflected sound waves to find objects; used by animals such as bats
eclipse an event in which the shadow of one celestial body falls on another
ecliptic the apparent path that the sun takes through the stars during the year
ecological footprint a calculation that shows the productive area of Earth needed to support one person in a particular country
ecological footprint
ecological succession a gradual process of change and replacement in a community
ecological succession
ecology the study of the interactions of living organisms with one another and with their environment
economics the study of how individuals and groups make decisions about the production, distribution, and consumption of limited resources as the individuals or groups attempt to fulfill their needs and wants
ecosystem a community of organisms and their a biotic environment
ecosystem services the role that organisms play in creating a healthful environment for humans
ecosystem services
ecotourism a form of tourism that supports the conservation and sustainable development of ecologically unique areas
ectoderm the outermost of the three germ layers of an embryo that develops into the epidermis and epidermal tissues, the nervous system, external sense organs, and the mucous membranes lining the mouth and anus
ectoparasite a parasite that lives on a host but does not enter the host's body
ectoplasm in ciliates, the region in the cytoplasm that is located directly inside the cell membrane and that does not usually have organelles
ectotherm an organism that needs sources of heat outside of itself
ectodermic describes the ability of an organism to maintain its body temperature by gaining heat from the environment
effective dose the amount of a drug needed to achieve the desired clinical improvement
effective dose
efferent neuron a neuron that conducts impulses away from the central nervous system
efferent neuron
effervescence a bubbling of a liquid caused by the rapid escape of a gas rather than by boiling
efficiency a quantity, usually expressed as a percentage, that measures the ratio of work output to work input
effusion the passage of a gas under pressure through a tiny opening
egg a sex cell produced by a female
ejaculation the expulsion of seminal fluids from the urethra of the penis during sexual intercourse
elapid a venomous snake that has two small, fixed fangs in the front of the mouth
elastic collision a collision between ideally elastic bodies in which the final and initial kinetic energies are the same
elastic collision
the energy available for use when an elastic body returns to its original configuration
elastic potential energy
elastic rebound the sudden return of elastically deformed rock to its undeformed shape
elastic rebound
elastic rebound theory the theory that states that earthquakes are caused by the energy released when rocks that are deformed by stress suddenly break along a fault and return to their original shape
elastic rebound theory
electrical conduction a method of charging an object that occurs when electrons are free to move from one atom to another
electrical conduction
electrical conductor a material in which charges can move freely
electrical conductor
electrical energy the energy that is associated with charged particles because of their positions
electrical energy
electrical insulator a material in which charges cannot move freely
electrical insulator
electrical potential energy the ability to move an electric charge from one point to another
electrical potential energy
electric charge an electrical property of matter that creates electric and magnetic forces and interactions
electric charge
electric circuit a set of electrical components connected such that they provide one or more complete paths for the movement of charges
electric circuit
electric current the rate at which charges pass through a given point; measured in amperes
electric current
electric discharge the release of electricity stored in a source
electric discharge
electric field the space around a charged object in which another charged object experiences an electric force
electric field
electric force the force of attraction or repulsion on a charged particle that is due to an electric field
electric force
electric generator a device that converts mechanical energy into electrical energy
electric generator
electric motor a device that converts electrical energy into mechanical energy
electric motor
electric potential the electrical potential energy of a charged particle relative to that of the surface of the Earth, which has zero potential
electric potential
electric power the rate at which electrical energy is converted into other forms of energy
electric power
electrochemical cell a system that contains two electrodes separated by an electrolyte phase
electrochemical cell
electrochemistry the branch of chemistry that is the study of the relationship between electric forces and chemical reactions
electrode a conductor used to establish electrical contact with a nonmetallic part of a circuit, such as an electrolyte
electrode potential the difference in potential between an electrode and its solution
electrode potential
electrolysis the process in which an electric current is used to produce a chemical reaction, such as the decomposition of water
electrolyte a substance that dissolves in water to give a solution that conducts an electric current
electrolytic cell an electrochemical device in which electrolysis takes place when an electric current is in the device
electrolytic cell
electromagnet a coil that has a soft iron core and that acts as a magnet when an electric current is in the coil
electromagneticinduction -the process of creating a current in a circuit by changing a magnetic field
the radiation associated with an electric and magnetic field; it varies periodically and travels at the speed of light
electromagnetic radiation
all of the frequencies or wavelengths of electromagnetic radiation
electromagnetic wave a wave that consists of oscillating electric and magnetic fields, which radiate outward at the speed of light
electromagnetic wave
electromagnetism the interaction between electricity and magnetism
electron a subatomic particle that has a negative charge
electron affinity the energy needed to remove an electron from a negative ion to form a neutral atom or molecule
electron affinity
electron capture the process in which an inner orbital electron is captured by the nucleus of the atom that contains the electron
electron capture
electron cloud a region around the nucleus of an atom where electrons are likely to be found
electron cloud
electron configuration the arrangement of electrons in an atom
electron configuration
electronegativity a measure of the ability of an atom in a chemical compound to attract electrons
electron microscope a microscope that focuses a beam of electrons to magnify objects
electron microscope
electron transportchain a a series of molecules, found in the inner membranes of mitochondria and chloroplasts, through which electrons pass in a process that causes protons to build up on one side of the membrane
electron transport chain
electrophoresis the process by which electrically charged particles suspended in a liquid move through the liquid because of the influence of an electric field
electroplating the electrolytic process of plating or coating an object with a metal
element a substance that cannot be separated or broken down into simpler substances by chemical means; all atoms of an element have the same atomic number
elevation the height of an object above sea level
elimination reaction a reaction in which a simple molecule, such as water or ammonia, is removed and a new compound is produced
elimination reaction
ellipse a closed curve in which the sum of the distances from any point on the curve to two fixed points inside the curve, called foci, equals the sum of the distances from any other point on the curve to the same two fixed points
elliptical galaxy a type of galaxy that has an elliptical appearance
elliptical galaxy
El Niño the warm-water phase of the El Niño–Southern Oscillation; a periodic occurrence in the eastern Pacific Ocean in which the surface-water temperature becomes unusually warm
El Niño
embryoan organism in an early stage of development of plants and animals
embryo in humans, a developing individual is referred to as an embryo from the second through the eighth week of pregnancy
embryo sac in plants, the female gametophyte that develops from a megaspore; contains the ovum that fuses with a sperm nucleus during fertilization to form an embryo and seven other cells, including the polar bodies that fuse with another sperm nucleus to form endosperm
embryo sac
emergent coastline the coast along which the sea level falls or the land rises
emergent coastline
emergent layer the top foliage layer in a forest where the trees extend above surrounding trees
emergent layer
emf electromotive force, the energy supplied by an electric current in a given source
emigration the movement of an individual or group out of its native area
emission spectrum a diagram or graph that shows how much radiant energy a substance emits with respect to wavelength
emission spectrum
emphysema a degenerative disease, especially of the lungs, in which air accumulates in the tissues and destroys the alveoli
empirical formula a chemical formula that shows the composition of a compound in terms of the relative numbers and kinds of atoms in the simplest ratio
empirical formula
emulsion any mixture of two or more immiscible liquids in which one liquid is dispersed in the other
endangered species a species that has been identified to be in danger of extinction throughout all or a significant part of its range and that is thus under protection by regulations or conservation measures
endangered species
Endangered Species Act a act that the U.S. Congress passed in 1973 to protect any plant or animal species in danger of extinction
Endangered Species Act
endemic species a species that is native to a particular place and that is found only there
endemic species
endergonic reaction a chemical reaction that absorbs energy
endergonic reaction
endocrine gland a ductless gland that secretes hormones into the blood
endocrine gland
endocrine system a collection of glands and groups of cells that secrete hormones that regulate growth, development, and homeostasis; includes the pituitary, thyroid, parathyroid, and adrenal glands, the hypothalamus, the pineal body, and the gonads
endocrine system
endocytosis the process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell
endoderm the innermost germ layer of the animal embryo; develops into the epithelium of the pharynx, respiratory tract, digestive tract, bladder, and urethra
Endodermis the single layer of cells that surrounds the vascular tissue in the roots and in some stems of plants; the innermost layer of cortex in seed plants
endoparasite a parasite that lives inside a host's body
endoplasmic reticulum a system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids
endoplasmic reticulum
endoskeleton an internal skeleton made of bone and cartilage
endosperm a triploid (3n) tissue that develops in the seeds of angiosperms and that provides food for a developing embryo
endospore a thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions
endosymbiosis a mutually beneficial relationship in which one organism lives within another
endotherm an animal that can generate body heat through metabolism and can maintain a constant body temperature despite temperature changes in the animal's environment
endothermic describes a process in which heat is absorbed from the environment
endothermic reaction a chemical reaction that requires heat
endothermic reaction
endotoxin a bacterial toxin that forms within the bacterial cell and that is released when the bacterial cell breaks apart
end point the point in a titration at which a marked color change takes place
end point
energy the capacity to do work
energy conservation the process of saving energy by reducing energy use and waste
energy conservation
energy conversion a change from one form of energy to another
energy conversion
energy efficiency the percentage of energy put into a system that does useful work
energy efficiency
energy level the energy state of an atom
energy level
energy pyramid a triangular diagram that shows an ecosystem's loss of energy, which results as energy passes through the ecosystem's food chain; each row in the pyramid represents a trophic (feeding) level in an ecosystem, and the area of a row represents the energy stored in that trophic level
energy pyramid
enkephalin a compound that is present in the brain and spinal cord that blocks pain
enthalpy the sum of the internal energy of a system plus the product of the system's volume multiplied by the pressure that the system exerts on its surroundings
entomology the study of insects
entropy a measure of the randomness or disorder of a system
Environment a membrane like layer that covers the capsids of some viruses
environment in ecology, the surrounding natural conditions that affect the life and development of organisms
environment in ecology
environment in physics, the combination of conditions and influences that determine the behavior of a system
environment in physics,
environmental impact a statement an assessment of the effect of a proposed project or law on the environment
environmental impact statement
the combined effect of the factors in an environment that prevent an organism from achieving its full biological potential
environmental resistance
the study of the air, water, and land surrounding an organism or a community, which ranges from a small area to Earth's entire biosphere; it includes the study of the impact of humans on the environment
environmental science
enzyme a type of protein that speeds up metabolic reactions in plant and animals without being permanently changed or destroyed
eon a unit of time equal to 1 billion years
epicenter the point on Earth’s surface directly above an earthquake’s starting point, or focus
epicotyls the portion of the stem of a plant embryo that is between the cotyledons and the first true leaves
epidemiology the study of the distribution of diseases in populations and the study of factors that influence the occurrence and spread of disease
epidermis the outer surface layer of cells of a plant or animal
epididymis the long, coiled tube that is on the surface of a testis and in which sperm mature
epiglottis a structure that hangs at the entrance of the larynx and prevents food from entering the larynx and the trachea while swallowing
epinephrine a hormone that is released by the adrenal medulla and that rapidly stimulates the metabolism in emergencies, decreases insulin secretion, and stimulates pulse and blood pressure; also called adrenaline
epiphyte a plant that uses another plant for support, but not for nourishment
epithelial tissue a tissue composed of cells that form a barrier between an organism and its external environment
epithelial tissue
epoch a subdivision of geologic time that is longer than an age but shorter than a period
equator the imaginary circle halfway between the poles that divides the Earth into the Northern and Southern Hemispheres
equilibrium in biology, a state that exists when the concentration of a substance is the same throughout a space
equilibrium in physics, the state in which opposing forces balance each other
equilibrium in physics,
equilibrium in chemistry, the state in which a chemical process and the reverse chemical process occur at the same rate such that the concentrations of reactants and products do not change
equilibrium in chemistry,
equilibrium constant a number that relates the concentrations of starting materials and products of a reversible chemical reaction to one another at a given temperature
equilibrium constant
equilibrium vapor pressure the vapor pressure of a system at equilibrium
equilibrium vapor pressure
equinox the moment when the sun appears to cross the celestial equator
equivalence point the point at which the two solutions used in a titration are present in chemically equivalent amounts
equivalence point
era a unit of geologic time that includes two or more periods
erosion a process in which the materials of Earth's surface are loosened, dissolved, or worn away and transported from one place to another by a natural agent, such as wind, water, ice, or gravity
erratic a large rock transported from a distant source by a glacier
erythrocyte a red blood cell
escape velocity the speed at which and direction in which a rocket must travel to completely break away from a planet's or moon's gravitational pull
escape velocity
esker a long, winding ridge of gravel and coarse sand deposited by glacial melt water streams
esophagus a long, straight tube that connects the pharynx to the stomach
ester an organic compound formed by combining an organic acid with an alcohol such that water is eliminated
esterificationan organic reaction in which an acid reacts with an alcohol to form an ester and water
estivation a period of inactivity and lowered body temperature that some animals undergo in summer as a protection against hot weather and lack of food
estrogen a hormone that regulates the sexual development and reproductive function of females
estuary an area where fresh water from rivers mixes with salt water from the ocean; the part of a river where the tides meet the river current
ethephon a chemical used as a growth regulator for fruit
ether an organic compound in which two carbon atoms bond to the same oxygen atom
Eubacteria in a traditional taxonomic system, a kingdom made up of all prokaryotes except members of the kingdom Archaebacteria; currently, biologists prefer to classify members of this kingdom into the domain Bacteria
Eukaryain a modern taxonomic system, a domain made up of all eukaryotes; this domain aligns with the traditional kingdoms Protista, Fungi, Planate, and Animal
eukaryote an organism made up of cells that have a nucleus enclosed by a membrane, multiple chromosomes, and a mitotic cycle; eukaryotes include protists, animals, plants, and fungi but not archaea or bacteria
eukaryotic cell a cell that has a nucleus enclosed by a membrane, multiple chromosomes, and a mitotic cycle
eukaryotic cell
Eustachian tube a channel that connects the middle ear to the mouth cavity
Eustachian tube
eutrophic describes a lake or other body of water that contains a rich supply of plant nutrients
eutrophication an increase in the amount of nutrients, such as nitrates, in a marine or aquatic ecosystem
evaporation the change of state from a liquid to a gas
evaporites sedimentary rocks formed from minerals left after water evaporates
evaporites sedimentary
evapotranspiration the total loss of water from an area, which equals the sum of the water lost by evaporation from the soil and other surfaces and the water lost by transpiration from organisms
evergreen describes woody plants that keep their leaves year-round
evolution a heritable change in the characteristics within a population from one generation to the next; the development of new types of organisms from preexisting types of organisms over time
excess reactant the substance that is not used up completely in a reaction
excess reactant
excited state a state in which an atom has more energy than it does at its ground state
excited state
excretion the process of eliminating metabolic wastes
excurrent siphon a tube through which water exits the mantle cavity of a bivalve
excurrent siphon
exergonic reaction a reaction in which the end product has less energy than the original material did; normally associated with catabolism
exergonic reaction
exfoliation the separation of thin layers from surfaces of massive rock due to rain
exocrine gland a gland that discharges its secretions through a duct
exocrine gland
exocytosis the process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out
exon the portion of the DNA sequence in a gene that contains the sequence of amino acids in a chain and the beginning and the end of a coding sequence
exoskeleton a hard, external, supporting structure that develops from the ectoderm
exosphere the outermost region of a planet's atmosphere in which the density is low enough that the lighter atmospheric atoms can escape into space
exothermic describes a process in which a system releases heat into the environment
exothermic reaction a chemical reaction in which heat is released to the surroundings
exothermic reaction
exotic species a species that is not native to a particular region
exotic species
exotoxin a potent, extra cellular toxin secreted by some bacteria
experiment a procedure that is carried out under controlled conditions to discover, demonstrate, or test a fact, theory, or general truth
experimental group in an experiment, a group that is identical to a control group except for one factor and that is compared with the control group
experimental group
experimentation the process of conducting an experiment
exponential group with a logarithmic growth, or growth in which numbers increase by a certain factor in each successive time period
experimental group
extensive property a property that depends on the extent or size of a system
extensive property
extensor a muscle that extends a joint
external fertilization the union of gametes outside the bodies of the parents, as in many fishes and amphibians
external fertilization
external respiration the exchange of gases between the atmosphere and the lungs
external respiration
external stimulus a stimulus that comes from outside the body
external stimulus
extinct describes a species that has died out completely
extinction the death of every member of a species
extreme halophile a member of the group of archaebacteria that live in extremely salty environments
extreme halophile
rock that forms from the cooling and solidification of lava at Earth's surface
extrusive igneous rock
eyespot an organ that is covered by pigment in some invertebrates and protozoa and that detects changes in the quantity and quality of light