763 terms

Middle School Science Vocabulary


Terms in this set (...)

the application of science through the use of special procedures or devices
dependent variable
a variable that is not under the expirementer's control
not changing or varying
a standard of measurement equal to a little over a yard
a standard of measurement
a standard of measurement equal to one thousandth of a meter
a standard of measurement equal to one hundredth of a meter
a standard of measurement equal to one tenth of a meter
a standard of measurement equal to one thousand meters
metric temperature scale on which water freezes at 0 degrees and boils at 100 degrees
tempurature scale on which water freezes at 32 degrees and boils at 212 degrees
a statement of scientific fact
an idea based on speculation
a theory which needs further investigation
the space inside of an object
the amount of matter an object contains
a trait or attribute
the standard against which experimental test results are compared
a measure of a quantity of mass per unit of volume
any group of organic compunds consisting of fats, oils, and related substances; a part of the structural components of a living cell
a single organic molecule that can join in long chains with other molecules
amino acid
nitrogen-containing organic molecules that from the basic buliding units of proteins
nucleic acid
a complex acid found in living cells
a class of organic chemical compounds that contains one or more rings of carbon atoms
a compound with repeating small molecules such as starch and nylon
crude oil found in sedimentary rocks and consisting mainly of hydrocarbons
a substance made by a chemical process
an organic chemical containing only hydrogen and carbon
organic compound
elements that exist together naturally without synthetic chemicals
containing the maximum amount of absorbed solvent
having double or triple carbon atoms
DNA (deoxyribonucleic acid)
substance carrying an organism's genetic information
a measure of quantity such as mass or electric charge per unit volume
a substance in which other substances are dissoloved
freezing point
the temperature at which a liquid becomes a solid
any mixture of two or more materials
a liquid that lowers the freezing point
the capacity for one substance to dissolve another
a chemical solution that contains a greater amount of solute than normally possible, often as a result of cooling
a chemical compound which separates into ions in a solution
a process in which an atom or molecule loses or gains electrons
the process by which an ionic solid will separate into its ions in a solution
an electrically charged atom or atom group
positive ion
an atom missing one or more of its electrons
a chemical bond between two atoms created by sharing a pair of electrons
with zero electric charge
a set of symbols representing chemical composition
oxidation number
the number of associated electrons in a compound
polar molecule
chemical compund with an unequally distributed electric charge
chemical compunds with an equally distributed electric charge
a compound containing water molecules
an attractive force that binds atoms and ions in a molecule
moldable, as in the characteristic of metals
the emission of energy in the form of streaming particles by substances such and uranium or plutonium
transition element
an element in groups of three through twelve of the periodic table
a partially conductive solid
having an atomic number over 92
one of several different forms in which a chemical element occurs, each with different physical properties but the same atomic compostion
a chemical process in which a solid is directly converted to a gas
having two atoms per molecule
relating to matter in the form of charged atoms or groups of atoms
containing or made of metal
a chemical substance that is water soluble, neutralizes acid, and forms salts with them
noble gas
a chemically non-reactive gas
the process of separating a mixture by evaporation and condensation
a suspension of small particles dispersed in another substance
the state of one substance being dissolved in another substance
a substance containing several ingredients which have been blended together
Tyndall effect
the scattering of light by minute particles in its path, such as dust in the air
a substance made by combining two or more different elements
a dispersion of fine solid particles in a liquid
a chemical substance consisting of different and distinguishable materials
a substance that can not be broken down into a simpler one by a chemical reaction
a specific metallic chemical element with a very high melting point
a stable, elementary particle that is a component of all atomic nuclei; carries a positve charge equal to that of the electron's negative charge
atomic number
the number of protons in the nucleus of an atom of an element
a form of an element with the same atomic number
periodic table
a table of chemical elemetns arranged according to their atomic numbers
an elementary particle without an electric charge
a stable, negatively charged elementary particle with a small mass that is a basic ingredient of matter and orbits the nucleus of an atom
a basic component of particles
a nonmetallic element that had properties between those of a metal and a nonmetal
a basic unit of matter; a molecule, atom, or electron
an element common in the Earth's atmosphere
a chemical element that is usually a shiny solid and conducts heat or electricity
a device that makes work easier to preform
simple machine
any device that only requires the application of a single force to work
Ideal Mechanical Advantage (IMA)
the factor by which a machine multiplies the force put into it
a tool or machine which perfroms a particular task or function
a toothed wheel that enagages another toothed mechanism in order to transmit motioin from one rotating body to another
the measure of a machine's energy effectiveness
wheel and axel
a simple machine consisting of a large wheel rigidly secured to a smaller wheel or shaft, called an axel
a sloped surface used to move from one level to another
a simple machine of the inclined-plane mtype consisting of a spirally threaded, cylindrical rod that engages into a similarily threaded hole
James Watt
engineer and inventor whose improvements of the steam engine led to its wide use in industry
a rigid bar that pivots around a fulcrum and is used to move or lift a heavy load at one end by applying force to the other
a block that is thick at one end and thinner at the other, used to secure or separate two objects
a wheel with a grooved rim over which a belt or chain or chain can move to change the direction of a pulling force
th point about which a lever turns
inclined plane
slanted surface used to raise or lower an object
an object on which a larger object turns
output force
energy or power produced by a system
input force
power or energy that enters a device and is recovered in the form of work or some other output effect
applied force
a force which is applied to an object by a person or another object
to cause something to increase in size or volume as a result of a rise in temperature or a decrease in pressure
buoyant force
a force that causes objects in a liquid to float or rise to the surface or upward in gas
Greek mathemetician, physicist, and inventor, best known for the lever and the pulley
the property orf a fluid that resists flowind
the random movement of atoms, molecules, or ions, from one site in a medium to another, resulting in complete mixing
the change of ice to vapor or vapor to ice without a liquid stage
a unit of energy equal to a nutritional calorie
boiling point
the degree of temperature at which a liquid turns to gas
heat of fusion
the heat released when liquid water freezes to solid ice
a hot ionized gas made up of ions and electronsfound in the sun, stars, and fusion reactors
a unit of pressure equal to one newton per square meter
SI unit
a unit of measure in the International System of Units
redused in volume by pressure
a substance that retains its shape
a substance whose shape can change but whose volume cannot
a substance that is neither a solid nor a liquid and that has the ability to expand
an abbreviation for oxidation-reduction, a process in which there is an electron transfer
a suspension of small solid particles formed in a solution as the result of a chemical reaction
a substance undergoing a chemical reaction
Antoine Lavoisier
French chemist know as the "father" of modern chemistry
a reaction that produces heat
a reation that abosorbs heat
chamical change in which a substance is broken down into two or more simpler substances
process in which a substance reacts forcefully with oxygen to produce heat and light
a chemical that increases the rate of a chemical reaction
process in which a substance, such as metal, is destroyed gradually by a chemical action
a chemical reaction which brings about a grain in hydrogen, a loss in oxygen, or an increase in electrons
the process of forming a complex compound from a chemical reaction involving two or more simpler elements
a chemical reaction in which energy is abosorbed
a corrosive substance with a pH less than seven; turns blue litmus paper red
a colorless, pungent, water soluble gas made up of nitrogen and hydrogen
an organic compund that changes color in acid or base
a way of determining the concentration of a solution
a chemical compound having pH between eight and fourteen; reacts with acids to form salts
a measure of acidity or alkalinity
buffer system
a substance that minimizes a change in the pH of a soluton by neutralizing added acids and bases
a synthetic polymer used in making textile fibers
a cleansing substance, especially a synthetic liquid that dissolves dirt and oil
the positive ion containing three hydrogen and one oxygen formed when an acid dissolves in water
the reaction of an ester with metallic base and water which produces soap
the addition of substances to neutralize water so that it is neither acidic nor alkaline
compressional wave
a wave that moves in the same direction as the periodic motion of the medium
the number of wavelengths that passes a fixed pont every second
the measurement of the height of a transverse wave
transverse wave
a wave that cause the crosswise disturbance of a medium
process in which two or more waves overlap and combine to form a new wave
the less dense region of a compressional wave
the change in direction that occurs when a light wave passes from medium to another of a different density
standing wave
a stationary wave which occurs when two waves of equal frequency and intensity traveling in oppostite directions combine
the scientific study of sound
a unit of relative loudness
a hollow chamber filled with air that amplifies sound
a way of locating an object using an emitted sound and the reflection back from it
frequencies which are multiples of the lowest or main frequency
a device that uses a cathode ray tube to show waveforms
diffuse reflection
1light that scatters in all directions when it strikes a rough surface
colored material used to change the colors of other substances
reflecting telescope
a telescope in which light from the object is initially focused by a concave mirror
not allowing light to pass into or through something
a glass object that can separate white light into a spectrum
optical axis
an imaginary line passing horizontally through the center of a compound lens system
cone cells
the cells in the retina which only function in relatively bright light
to cause light to vibrate within certain planes
an optical lens defect in which light rays are prevented from meeting at a single pont, producing an imperfect image
a light emitted as a result of being heated to a high temperature
focal point
the point where rays from a lens converge
a light-sensitive membrane in the back of the eye that receives an image from the lens and sends it to the brain
coherent light
light waves that vibrate with constant phase relationships that are produces by a laser or a combination of two prisms
a device which emits a focused beam of light
parallel circut
a closed circut in which the current divides into two or more paths before recombining to complete the circut
the tendancy for a material to oppose the flow of electrons
a device used to detect and measure an electric charge
the SI unit of electric charge
the SI unit of electrical current
the SI unit of power
the unit of electromotive force and electric potential
a thin wire conductor in a light bulb
series circut
a circut through which the electrical current flows in a single continuous path.
a unit of electricity equal to 1,000 watts
static electricity
a stationary electric charge that builds up on an insulated object
a substance or medium that allows heat, electricity, light, or sound to pass along it or through it
kinetic energy
energy that a body possesses becasue of its motion
a device that changes electrical energy from one alternating circut to another
a soft metal core made into a magnet by the passage of electricity through a coil surrounding it
a type of electromagnetic constructed so that the core moves, usually linearly, when electricity is passed through it
magnetic field
a space surrounding a magnetized body or current-carrying circut
a phenomenon occuring in the night sky around the polar regions, caused by gases in the atmosphere which interact with solar particles
a device for finding direction which uses a magnetized needle that automatically swings to the magnetic north
magnetic domain
a small, magnetized region of a magnetic surface
an instrument used to measure electric current by means of a coil in a magnetic field that moves a pointer or light
the quality or having two oppositely charges poles, one positive and one negative
a piece of metal that has the power to draw iron or steel objects toward it and to hold or move them
the process that changes one element into another through nuclear delay
srong force
the force that holds particles together in a nucleus
alpha particle
a positive particle consisting of 2 protons and 2 neutrons; the nucleus of a helium atom
alpha radiation
the least-penetrating type of radiation; can be stopped by a sheet of paper
cloud chamber
a device used to detect the movement of high energy particles as they pass through a chamber of supersaturated vapor
Geiger counter
a device used to detect and measure radiation
beta particle
an electron created by radioactive emission
a radioactive isotope that can be detected by the radiation it emits
bubble chamber
a chamber in which the trail of a particle can be observed as a line of bubbles created by a particle
chain reaction
a series of nuclear reactions in which neutrons produced by a fission cause more friction
the amount of movement in a particular direction
a physical influence that tends to change the postion of an object with mass
the tendancy for a body at rest to stay at rest, or a body in motion to stay at motion, unless acted upon by a force
resistance encountered by a moving object
static friction
resistance between two objects that are in contact but are not moving
sliding friction
the frictional resistance an object in motion experiences
the speed at which something moves or happens
the rate at which something increases in velocity
moving or pulling toward a center or axis
the force that tends to pull all bodies in Earth's sphere toward the center of the Earth
a branch of mathematics that studies continuously changing quantities
air resistance
the force of air pushing against a moving object
the gravitational force exerted on a mass
the motion of a body and its resistance to slowing down
a substance or material of a particular kind
a photoelectric cell that detects and measure light intensity
solar thermal
the use of radiation from the sun to produce heat energy
an unlimited supply or resource
fractional distillation
the separation of components from a volatile liquid that have different boiling points
a machine which uses steam or another fluid in motion to move rotation blades; the rotay motion is then turned into electrical or mechanical power
a device that converts mechanical energy into electricity
the mass or organisms in the ecosystem, measured in terms of weight per unit of area
used to describe ricks formed from eroded material
geothermal energy
the heat energy found below the earth's surface
fossil fuel
fuel made from decomposed remains of prehistoric plants and animals
gamma radiation
high-energy electromagnetic raditation
mechanical advantage
the ratio output force to input force for a machine
law of conservation of mass
the scientific law which states that mass can be neither created nor destoyed during a chemical reaction, only changed from one form to another
to undergo spontaneous disintergration
a reddish brown metallic chemical element that bends easily and is a good conductor of electricty and heat
a light metallic element that is ductile, malleable, and resistant to corrosion
focal length
the distance from the center of a lens to the focal point
specific heat
the amount of heat needed to raise the temperature of one gram of substance by one degree
process by which plants use sunlight, carbon dioxide, and water to make food; also produces a large part of the oxygen in the atmosphere
system of naming plants and animals
the part of a cell which contains genetic material
carbon dioxide
a nonpoisonous gas created by respiration and by the decomposition of living organisms
structures in the cells of leaves contain chlorophyll
endoplasmic reticulum (ER)
a net-like system within the cytoplasm involved in the synthesis, modification, and transportation of cellular materials
an organism that causes an infectious disease
a group of related organisms sharing common characteristics
the scientific classifications into which organisms are grouped
compartments within cells that perform specific functions; the nucleus, for example
the process by which a cell divides
meiosis cell
division that produces reproductive cells
stage of mitosis when the chromosomes line up along the center of the cell
stage of mitiosis in which the chromosomes begin to separate
Punnett square
tool used to show the potential offspring of two parents
a structure in the nucleus of a cell composed of DNA and protein
the observable characteristics of a cell or organism
gene that determines the characteristics in the organism
having two identical versions of a specific gene
possessing two different forms of a specific gene
a person who specializes in animal life
a whip-like structure of a cell responsible for cell movement
a naturally occuring substance in a plant thta gives the plant its color
a rod-shaped bacterium
process used to clean up contaminated land using bacteria and organisms to neutralize soil contaminants
a kind of bacterium with a spherical shape
the division of a single-celled organism into two equal parts
a microorganism that does not require oxygen for growth
structure that allows bacteria to stick to surfaces
a spiral-shaped bacterium
an organelle that produces protein in cells
cellular substance which surrounds the nucleus and holds genetic material
a single-celled organism found in fresh and marine waters with characteristics of both plants and animals
a plant-like organism which does not make chlorophyll
a single-celled organism that can move and feed on organic compounds
the specialty of studying fungi
a plant spore formed by meiosis
a plant that is a combination of a fungus and an agla; commonly grows on trees or rocks
single-celled organism which has an eukarotic cell but is not a member of the plant, fungal, or animal kingdoms
an asexual reproductive structure which can produce a new organism; fungi, algae, and many other organisms produce spores rather than seeds
simple. rootless plants tha grow in water in proportion of availible nutrients
green pigment found in plants, algae, and some bacteria; needed to aid in the process of photosynthesis
African sleeping sickness
disease transmitted by the bite of the tsetse fly
relating to plants with tissues that have the ability to carry fluid
flowering plant whose seedlings have two seed leaves; for example, a bean
a plant with bare seeds, as with the pines, where the seeds are attached at the base of the scales in the cone
a type of plant tissue that carries water and dissolved minerals from the roots through the stem and leaves
a flowering plant whose seeds have a covering of some kind, such as a pod or a fruit
food-transporting tissue of a plant; also know as the inner bark
the seed-bearing part of pines and firs
a flowering plant whose seedling has only one seed leaf; for example, grass
the waxy, protective layer which covers the stem, leaves, and flowers of many plants and helps provent water loss
small, leafy flowerless plant that grows in moist, shaded areas
the process of reproduction by pollination
small structure in a seed plant that contains the eggs and, when fertilised by pollen , develpoes into seeds
the part of the flower's female reproductive system taht receives the male pollen grains
the beginning growth of a seed or spore
a close association between two different species in which both species benefit
the part of the flower which produces pollen
refers to the leaf structure of ferns or palms
the tissue of a seed containing the nutrients
the spore-producing stage in the life cycle of a plant
the lower part of the pistil that contains immature seeds
tiny pore in the outer layer of a plant leaf that regulates the movement of gases(water vapor and others) between the plant and the atmosphere
process by which energy is released by food
an organism which makes its own food
the outside layer of cells on a plant which helps prevent injury
energy-producing cellular organelles found outside the nucleus that convert food to energy
plant growth toward or away from an environmental stimulus such as heat or light
the cause of physical response in an organism
a regulating chemical in plants
a space in the cytoplasm of a cell which stores food and fluid
cell wall
a tough, rigid structure outside of the cell membrance in plant cells
invertebrate water animal which has tentacles
an animal whose food source consists of both plants and animals
an animal which feeds only on grass and other plants
an animal with a backbone
an animal that eats other animals
a cnidarian with a cylindrical body
a cnidarian with a transparent, umbrella-shaped body
plants and animals which closely resemble another species as a form of protection
an organism that lives and feeds on another living organism for competion of its life cycle, and which is typically detrimental to the host
the characteristic of being the same on both sides of a central dividing line
sea anemone
colorful sea animal of the cnidarian family which attaches to rock or other nonliving material
a sessile marine organism with a porous, fiberous skeleton
invertebrate animals that have jointed bodies and jointed limbs
the change which takes place as an animal developes into an adult (tadpole to frog, caterpillar to butterfly)
a band of tissue containing rows of small teeth in the mouths of some mollusks
a marine invertebrate animal with tube feet and five-part radially symmetrical bodies
an athropod's process of shedding an old exoskeleton
rigid, bristle-like structures in worms that assist in movement
an invertebrate with a soft, unsegmented body; usually has a shell
small opening in an insect along the side of the thorax or abdomen controlling the flow of air into and out of the body
a body part that sticks out from the main part of the body
a mollusk with a hinged shell; oysters, mussels, and clams are examples
structure in invertebrates and fish where digestion occurs
a pouch in athe digestive tract of an insect or earthworm
gard, protective outer covering of an organism
a cold-blooded animal which breathes air and lays eggs
a cold-blooded animal that spends time on land but breeds in water
the internal skeleton of an animal
the tough, elastic tissue in the body
warm-blooded animals who are equipped to nurse their young
warm-blooded animal which can maintain its body temperature regardless of temperature changes in its environment
cold-blooded animal which maintains its body temperature by taking in heat from its environment
a poisonous fluid produced and injected by an animal to protect itself or to subdue its prey
a dormant, sleeplike state accompanied by a very low body temperature and metabolic rate; certain animals fall into this during winter
a rod of cells that supports the body of a chordate
bony plates on fish, some reptiles, and mammals
immature or early form of an insect, amphibian, or fish
a covering of soft hair or fluffy feathers
a very large, plant-eating mammal that lives in warm coastal waters
an egg-laying mammal
a mammal with a pouch used to carry their immature young
the period of time when the embryo develops in the uterus
fibrous protein found in hair, nails, feathers, and hooves
vascular organ that supplies food and oxygen to the fetus inside the uterus of a pregnant mammal
the process birds go through to clean and to rub oil over their feathers
the body's blood-pumping system
contour feathers are the tail and wing feathers, the strong and stiff ones adapted for aerodynamics and speed
occuring repeatedly during specific intervals of time
behavior of a species living together in a group
the early social attachment of animals that results in strong behavioral patterns specific to its own species
a cyclical behavior in which a group of animals move together from one region to another
a scent which is secreted by an animal, influencing behavior and development of other members of the same species
behavior in which an animal reacts out of a strong natural impulse
qualities which are present at birth
a learned behavior which allows animals to use past experiences to solve new problems
a territorial behavior exhibited by the threatening actions of one animal to another
the light given off by some organisms such as fireflies
animal tendency to protect an area from intruders of the same species, especially other males
a connective tissue that attaches a muscle to a bone or other body part
the layer of skin under the epidermis which contains blood, lymph vessels, sweat glands, and nerve endings
skeletal system
the system of bones supporting the soft tissue and protecting the internal organs of the body
an elastic tissue that functions to produce movement of body parts and body fluids
the connective tissue surrounding all bones of the body except those at the joints
the bands of tough tissue that connect bones or cartilage at a joint or that support an organ or muscle
a dark brown or black pigment found in skin, hair, eyes, fur, or feathers of people, animals, and plants
the point at which two or more bones in the body come together
a discoloration of the skin caused by injury to blood vessels
a controlled response
an uncontrolled response
a substance that provides nourishment for the body
the breaking down of food in the body so that it can be used or excreted
salivary glands
glands that producce and release digestive juices (saliva) in the mouth
food energy source for humans and animals such as sugar and starch
part of the small intestine
the pathway in the throat through which food moves between the throat and the stomach
a protein controlling biochemical reactions
a mass of partially digested food and gastric secretions passed from the stomach to the small intestine
a food source rich in amino acids
involuntary muscle contractions that transport food and waste through a tube-shaped organ such as the intestine
a unit of energy equal to the heat needed to raise the temperature of one kg of pure water by one degree Calcius
one of the upper chambers of the heart
the lower chambers of the heart
fluid containing the white blood cells
pulmonary circulation
the flow of blood from the heart to the lungs and back to the heart
the clear, yellow fluid part of blood
a heart valve with three flaps; prevents blood from flowing back into the right atrium when the right ventricle contracts
a heart valve that lies between the left atrium and left ventricle; prevents blood from flowing back into the left atrium when the left ventricle contracts
a vessel that transports or contains lymph
colorless cells whose main function is to control bleeding
cardiovascular system
the system made up of heart, blood vessels, and blood
unable to be seen without the aid of a microscope
the thin blood vessels that connect small arteries with small veins
systemic circulation
the circulation of the blood throughout the body
elevated blood pressure
the arteries and veins that supply blood to and from the muscle tissue of the heart
the process of distributing nutrients to the cells
the main artery leaving the heart
vena cava
main veins leading into the heart
blood vessels
tubes that carry blood throughout the body
the two main air passages leading from the trachea which allow air to move in and out of the lungs
the liquid waste product of vertebrates
cellular respiration
the process by which glucose is converted into energy
air sacs in the lung
respiratory system
the system of organs that process air in the body, including the nose, throat and lungs
respiratory disease characterized by wheezing and shortness of breath
the pair of organs responsible for filtering waste liquid in the body
the airway that leads from the larynx to the lungs
muscular wall below the rib cage which expands the chest for breathing
lung disease in which the air sacs are dilated resulting in breathing impairment
excretory system
the organs that elimate waste from the body
small tubes in the kidneys
the tube that carries urine from the bladder to the outside of the body
a simple sugar which is the main source of energy for the body
a rounded part of an organ, as in the lungs, brain, or liver
the mechanical filtering of waste products from the blood of a patient whose kidneys are not working properly
nervous system
the body system that receives stimuli, decides on their importance, and sends nerve impulses to the organs of action; consists of the central nervous system ( brain and spinal cord) and the peripheral nervous system (all nerves outside of the brain and spinal cord)
cells that transmit nerve impulses and are the basic units of the nervous system
the extensions of a nerve cell that transmit impulses outward or away from the cell body
extensions of a nerve cell that receive electrical signals
central nervous system
the control network for the human body; is composed of the brain and spinal cord; one of the two major divisions of the nervous system
part of the brain which controls and coordinates muscular activity and balance
a light-sensitive membrane in the back of the eye which receives an image from the lens and sends it to the brain
tiny bone located in the inner ear
brain stem
the part of the brain closest to the spinal cord that controls involuntary functions like breathing and heart rate
liquid secreted into the mouth by the salivary glands which moistens food and begins the breakdown of starches
peripheral nervous system
the nerves in the body that lie outside of the brain and spinal cord
curved inward
curved outward
relating to the skull
somatic system
system that controls all voluntary systems within the body with the exception of reflex arcs
autonomic system
the part of the nervous system that controls involuntary activity such as the action of the heart, lungs, and intestines
olfactory cells
relating to the sense of smell
cells in the retina used to detect shape and movement
the natural regulatory mechanism of the body
taste buds
receptors primarily on the tongue that enable us to detect sweet, salty, sour and bitter
endocrine system
the system of glands in the human body which is responsible for producing hormones
relating to twins that developed from two seperate ova, rather than a single ovum
relating to twins that developed from a single ovum in a single placental sac; these twins closely resemble one another
amniotic sac
the sac which holds the baby in the uterus; contains the baby, placenta and amniotic fluid
the production of offspring
produced by the endocrine glands, these substances act as messengers to cells and organs in the body
the state of physical development when sexual reproduction first becomes possible
in mammals, a stage of development in which all organs have formed, from the eighth week after conception until the moment of birth
in mammals, the stage of development from conception to eight weeks
thyroid gland
the gland which helps regulate growth and metabolism
thymus gland
a gland involved in the development of cells of the immune system
pituitary gland
the main gland of the endocrine system
pineal gland
small gland responsible for production of melatonin
the organ which holds and nourishes the embryo during development
immune system
system that works to seek and kill invaders of the body
menstrual cycle
monthly cycle of female hormonal changes from the beginning of one menstrual period to the beginning of the next
the ripening and release of an egg or eggs from the ovary for possible fertilization
the pouch of skin and muscle containing the testicles
umbilical cord
the cord that carries blood, oxygen, and nutrients from the plancenta to the baby during pregnancy
an organ that produces and releases one or more substances for use in the body
organs at the back of the throat that help the body figh toff viral and bacterial infections
a protein that combines with an antigen and counteracts in its effects
any substance that triggers an allergic reaction
a body's ability to resist a specific disease
easily transmitted from one person to another
carrier of an infectious agent; capable of transmitting infection from one host to another
a substance that simulates the production of antibodies
chronic illness
a recurring ilness
a mineral fiber used in the past for fireproofing and insulation; banned by EPA because it was found to cause caner when inhaled
the molecules
the smallest parts of matter
a disease-producing organism
the use of chemical agents to treat cancer and other diseases
the process by which some bacteria use chemicals to provide the energy they need for life
the process in which a liquid is changed to a vapor without its temperature reaching the boiling point
water droplets that form on cold surface when warmer air comes in contact with it
the loss of water vapor from a plant's surface
the formation of rain, snow, or hail from moisture in the air
a community of different species interacting with one another and their environment
an ecological community of organisms and environments
sub-arctic forests located south of a tundra
treeless plain between the ice cap and the timber line that had permanently frozen subsoil
an area of land, marsh or swamp, where the soil near the surface is covered with water
acid rain
rain that has becom acidic from mixing with industrial pollutants in the atmosphere (like oxidated sulphur and nitrogen)
the processing of waste for reuse
solar energy
using the sun as an energy source
nuclear energy
energy released by nuclear fission or fusion
nitrogen cycle
nitrogen circulation between air and plants
a mixture of fog and smoke which creates a type of pollution
energy pyramid
a pyramid diagram showing the loss of useful energy at each steop in a food chain
covalent bonds
chemical bonding where some atoms share electrons to hold a molecule together
term used to describe a group of atoms connected by covalent bonds
substance made up of more than one element
states of matter
solids, gases, liquids, and plasmas
substance composed of only one type of atom
solids in which the atoms are arranged in a repeating, orderly pattern
property revealed by rubbing a mineral on an unglazed seramic tile to determine the color of the mineral in powdered form
term used to describe how a mineral reflects light
salt or sodium cholride; colorless or white mineral occuring as cubic crystals
mineral properties
luster, streak, hardness, and fracture
strength of the structure of the mineral compared to the strength of its chemical bonds, tested through scratching
one way that a mineral can break; smoothly curved, irregular, jagged, or splintery
nonmetallic element found only as a compound with other elements in nature
another way that a mineral can break; found mainly in crystalline minerals like diamonds which can break in straight planes when struck
particles of eroded rock or other plant or animal matter that are transported and deposited by water, wind, ice, or gravity
foliated rock
rock that has a layered appearance, formed or composed of separable layers
igneous rock
type of rock formed by intense heat or from solidification of molten magma
type of rock formed from eroded material or sediment
type of rock characterized by a change in physical form, appearance, or character
type of molten rock that comes from a volcano; magma that has reached the surface of earth
intrusive rock
type of rock that is formed by being forced into the holes, cracks, or layers of preexisting rocks while in a molten state
volcanic glass that is formed by rapid cooling of lava and usually black in color; used by early civilizations to make tools and special objects
molten rock that is in a liquid state under the earth's crust; forms igneous rock when cooled at earth's surface
black or dark brown sedimentary rock used as a fuel; formed by the decompostition of plant material
how far north or south of the equarot a point id on earth's surface
prime meridian
imaginary line that runs from north to south though Greenwich, England; at 0 degrees longitude, all other longitudes are figured from this one
the east or west distance between a point on the earth and the prime meridian
map projection
a flat map that shows our three-dimensional eath
the study and creation of maps
height of an area, object, or land form on the earth's surface above sea level
topographic map
map showing the physical features and elevation of an area
coastal plain
flat. low-lying land next to a sea coast
an elevated, mostly level or flat area of land
vent or opening in earth's surface through which molten magma (lava), ash, and gases are released
mountain formed by the uplift of land between faults or the lowering of land outside of the faults
imaginary circle around the surface of earth halfway between the North and South Poles
layers of soil visible in a vertical cross section
chemical reaction where oxygen is combined with another element or compound to yield a different compund (example: iron + oxygen + rust)
process where dissolved carbon dioxide in rainwater creates carbonic acid and reacts with minerals in a rock to break it down
process where hydrogen in rainwater reacts with minerals in a rock to break it down
form of weathering that occurs when sand or other small particles transported by air collide with surfaces and break them down
chemical weathering
process in which rocks decompose or disintergrate by chemical processes such as oxidation, carbonation, or hydrolysis
mechanical weathering
process where rocks are broken down into smaller pieces and their edges are rounded by abrasion, gravity, and freezing water
the wearing away of land surface (soil) or rocks by wind, water, or ice
process by which soil nutrients are carried away by water or washed deeper into the soil
sedimentary rock formed mostly from the calcium carbonate remains of marine animals such as shells; used to make cement and lime
terrace farming
transformation of a cary steep slope into usable farmland by creating a series of level steps or terraces; these terraces or steps retain water and keep plants and seeds from washing downhill
very large mass of ice and snow that moves slowly downhill because of its own weight; is an agent of erosion; formed in areas where sonw falls faster than it melts
mass movement
downhill movement of earth materials due to gravity
form of erosion caused by gravity where uphill particles fall downhill very slowly; form of mass movement
rapid downward movement of wet soil; form of mass movement
mass movement or lanslide where moving earth moves downward in a block or multiple blocks and can create a small upslope in the process
downward movement of earth
beach erosion
the wearing away of a beach by tides, currents, and waves
wind erosion
wind action primarily known for smoothing and rounding landscapes as sand and dust carried by wind wear away rocks and land surface
windblown, dusty, chalky soil or silt; usually yellowish-brown
scratch or groove on a rock formed by a glacier or stream
opposite of erosion; also known as sedimentation; sediment which eroded from another location, was transported by wind,water, or ice, and deposited
wind erosion where sand, clay, and silt particles are removed from the land's surface
long, winding ridges of sand and gravel deposited by streams that flows in or under glaciers
glacial till
rocks and material left behind by a glacier
new landform crated by the accumulation of rocks, soil, and other debris carried and deposited by a glacier (glacial till)
bowl-shaped valley with steep walls on a mountain eroded by a glacier
very thin outer layer of the earth (25 miles under the continents, two to three miles under the oceans); broken into pieces called plates
thickest layer of the earth (about 1800 miles thick); made of hot, dense rock that flows and moves due to temperature differences in the mantle
outer core
1800 miles beneath the crust; composed of nickel and iron in a liquid state due to high temperatures
inner core
very hot (4,000 to 9,000 degrees F) solid center of the earth composed mainly of nickel and iron; solid due to extremely high pressure; about 3200 miles below the earth's surface and about 800 miles thick.
point on the earth's surface directly above the source of an earthquake
device that detects, measures, and records earthquake vibrations
scientist who measures and studies earthquakes
Richter Scale
collection of mathematical formulas that measure the strength of an earthquake; developed by Charles Richter in 1935
huge ocean waves generated after an earthquake at sea where there is a sudden drop or rise of a large section of the ocean floor
surface wave
vibration from an earthquake that travels along the surface of the earth and can topple buildings during an earthquake
body waves
vibration from an earthquake that travels deep within the earth; two types are primary and secondary waves
primary wave
type of body wave that compresses and expands rock as it travels through the earth
secondary wave
type of body wave that shakes and twists the earth sideways as it travels; moves at about half the speed of the primary wave
measure of the size or energy of an earthquake
property that alllows a material to bend and change shape
seismic wave
vibration that travels through the earth, usually due to an earthquake
process of changing a solid or gas into a liquid
normal fault
break in the earth's crust where a block of rocks shifts downwards
strike-flip fault
break in the earth's crust where rocks on either side of the fault split and slide past each other
plate boundaries
edges of the plates that make up the broken surface of the earth
volcanic eruption
violent discharge of steam, lava, and ash from a volcano; usually occurs on or near the continental plate boundaries; produces ash, granite and basalt
flat mass of igneous rock between two layers of older, existing sedimentary rock; mass is usually horizontal
volcanic neck
massive, crudely cylindrical pillar of rock that was the inside (neck) of a volcano which filled with magma and hardened many years ago; is now exposed due to surface area erosion around the projection
huge mass of igneous rock (greater than 40 square miles) with no known bottom; believed to have solidified deep within the earth
large bowl-shaped volcanic depression formed at the top of a volcano when the vent collapsed; sometimes filled with water
volcano on the Indonesian island of Rakata; has erupted many times throughout history with disastrous consequences
Hawaiian Islands
islands in the Pacific Ocean; formed in a nearly straight line because the Pacific plate moved very slowly over a hot spot in the Earth's mantle layer
La Soufriere
volcano on the Caribbean island of Montserrat known for its high levels of silica, a substance potentially hazardous to humans
youngest volcano on the Big Island of Hawaii; possibly the world's most active volcano with continuous eruptive activity since 1983
bits of solidified lava that fall from the air and can be as small as ash or as large as rocks
Mt. St. Helens
active volcano in Washington state that had a massive eruption in 1980 which produced tremendous amounts of ash
composite volcanos
tall, symmetrical, steep-sided volcanoes, also known as stratovolcanoes
shield volcano
flat, broad volcano such as Mauna Loa in Hawaii
Paricutin Volcano
Mexican volcano that appeared first as a crack in a cornfield then eventually produced 10 square miles of lava and buried most of Paracutin and nearby San Juan
cinder cone
volcanic cone that forms above ground around a vent; is made of cinders (loose volcanic fragments) and bombs (ashes and blobs of congealed lava)
name given to ancient super-continent consisting of all of earth's masses; theory was proposed by German meteorologist Alfred Wegener in 1915
continental drift
the gradual movement and formation of continents; idea supported by fossil evidence of same unique plants/animals on multiple continents
plate tectonics
theory that the earth's surface is broken into plates the size and position of which change over time; this theory supports the continental drift theory
subduction zone
an area on earth where two tectonic plates meet; one plate slides underneath the other, moves down into the mantle and melts
traces or remains of animals or plants from long ago
crust and the uppermost part of the earth's mantle
lower layer of the mantle that flows and moves the plates of the earth
ropy lava
long trails of lava that form spirals
magnetic reversals
changes in earth's magnetism (evidenced in rods) due to slow movements in earth's liquid outer core; this phenomenon supports the idea that the sea floor is changing and spreading
material movement in gases and liquids due to density or concentration differences which are often a result of heat
fossil formation
accomplished by permineralization, carbon film, or molds
the process in which minerals are deposited into a bony fossil
carbon film
a type of fossil formation normally involving plants where a plant's oils leach out and only a black carbon film remains
a type of fossil formation where an organism is buried in mud, clay, or another material which hardens, the organism decays, and an imprint of the organism is left in the hardened material
rock record
ancient history recorded in rock layers
a boundary seperating two or more rocks of markedly different ages, marking a gap in the geologic period
index fossils
fossils that existed during limited periods of time; used to determine the age of the rocks in which they are preserved
carbon dating
dating method that uses carbon-14 to determine the age of the materials
principle which states that sediments formed in ancient sedimentary rocks were deposited in the same way sediments are deposited today
principle stating that in undisturbed situations, the oldest layers of rock are on the bottom
fossilized footprints
evidence of early human ancestors found by Mary Leakey in Africa
extinct marine organism that lived in earth's oceans for more than 200 million years; thought to be ancestor of today's joint-footed organisms; crabs, centipedes, spiders, etc.
longest block of time in geology
period of time that is a sundivisioin of an eon
divisioin of an era into smaller time frames
division of a period into smaller time blocks
Precambrian Eon
time period from the formation of earth up until about 600 million years ago
Phanerozoic Eon
time period from 600 million years ago until now
Paleozoic Era
time period from about 600 million years ago to 245 million years ago when the super continent pangaea is thought to have been formed and the first fish, land plants, amphibians, and reptiles firs appeared; first era of the Phanerozoic Eon
Mesozoic Era
time period from between 245 million years ago to 5 million years ago when dinosaurs, the first birds, and mammals appeared; period ended by mass extinction; second era of the Phanerozoic Eon
Cenozoic Era
time period that spans from 65 million years ago until now; the Age of Mammals; the third era of the Phanerozoic Eon
organism from the Precambrian Eon that contained chlorophyll and contributed oxygen to earth's atmosphere through photosynthesis; created our oldest fossils
Charles Darwin
English scientist who wrote the book The Origin of Species (1859) and achieved lastingn fame for his theory of evolution
process of change over time
mobile, meat-eating dinosaur from the Jurassic period
group of organisms that normally breed only among themselves
lowest layer of earth's atmosphere; extends from earth's surface up to about 8 miles high
atmospheric layer above the troposphere; 9 to 31 miles above the earth
layer above the stratosphere; about 31 to 50 miles above the earth
outermost layer of earth's atmosphere where gas molecules split apart into ions
lower part of the thermosphere; reflects radio waves
sea breeze
a breeze that forms when warmer air over the land rises and cooler costal air rushes in to replace it
atmospheric pressure
force exerted by the weight of the air; as altitude (height above earth's surface) increases, atmospheric pressure decreases because air is less dense, and vice versa (altitude decreases, pressure increases)
water cycle
continuous process of moving water from the earth to the atmosphere and back again; evaporation, condesation, precipitation
ozone layer
exists in the stratosphere; atmospheric layer of oxygen that exists as ozone and absorbs harmful ultraviolet radiation
jet stream
fast moving river of air that flows from east to west over North America and directs our weather systems
trade winds
strong tropical winds blowing toward low pressure regioins at the equator; the blow from east to west in the Northern Hemisphere
prevailing westerlies
winds in the middle latitudes that generally blow opposite the trade winds; primarily responsible for blowing weather patterns across the United States
areas near the equator where the is little or no wind
transfer of heat through materials
heat transfer by circulation through a gas or liquid
energy or heat carried in waves or rays
coriolis effect
curving motion of wind or water caused by the earth's rotation
also know as CFC's; chemical substances once used in refridgeratiors and air conditioners that destroy the ozone layer when they break down
state of the atmosphere at a specific time and place
water vapor in the air
severe storm with a violent, rotating column of air that can have wind speeds greater than 150 miles per hour
tropical storm
organized thunderstorm over tropical waters with winds from 39 to 74 miles per hour; storm winds spin due to earth's rotation
severe tropical storm with sustained winds of 75 miles per hour or more; starts over the ocean and is the most powerful type of storm on earth
cirrus clouds
high, thin, featherlike clouds of ice crystals
altocumulus clouds
white or gray medium altitude clouds that usually occur in layers or patches of wavy rounded masses or rolls
stratus clouds
low, gray, uniform cloud layer that usually covers the sky
cumulonimbus clouds
thunderstorm cloud that is extremely dense and tall, associated with lightning, thunder, hail and sometimes tornadoes
dew point
specific temperature when water vapor in the air condenses
water that falls to earth as rain, snow, hail or sleet
average weather pattern of a region that occurs over many years and is influenced by latitude, ocean currents, mountains, and large bodies of water
destruction of forests
greenhouse effect
warming of the earth's atmosphere due primarily to heat trapped by gases such as carbon dioxide, methane and water vapor; deforestation adds to this problem because it removes trees that would have removed carbon dioxide from the air and reduced the greenhouse effect
El Nino
weather pattern usually occurring every 3 to 5 years when abnormally warm surface waters occur in the Pacific Ocean near Peru
Gulf Stream
warm ocean current that flows from the Gulf of Mexico along the east coast of the U.S. and northeast across the Atlantic Ocean
process of removing salt from water
upward motion of cold, dense, nutrient-rich water toward the surface
continental shelf
shallow bottom just offshore of most continents between the beach (edge of the water) and a sharp underwater drop-off where the bottom plunges steeply
distance from crest to crest of a wave
stream of water that moves horizontally in the ocean
ocean pollution
major causes include: 1) toxic (poisonous) trash and chemicals that get into our food chain, 2) oil, primarily occurring as runoff from the land, and 3) dangerous debris like plastics that can entangle animals and harm marine life when eaten
the daily, regular rise and fall of the ocean waters due to the moon's gravitational pull on the earth
benthic organisms
bottom-dwellers in a body of water
minute animals and plants that are free-floating and unable to swim against currents
water animals that are active swimmers and capable of swimming against a current; not plankton
wide part of a river where it joins the sea; fresh and salt water mix here
food chain
a hierarchy of living things (animals and plants) where each level is dependent on the next for its nourishment
ocean waves
as water molecules in a wave move up and down in a circular pattern, the energy of the wave moves toward the shore; friction with the bottom slows the wave as it nears the shore
sting ray
fish with a flattened body and a long, narrow whip-like tail with a venomous stinger; can inflict severe wounds
free-swimming sea animal with a bell-shaped, jelly-like body and stinging tenticles
a measure of acidity or alkalinity
acidity of a water sample is determined by titrating it with a strong base (eg, NaOH) to a defined pH; pH less than 7
a pH of more than 7; the solution is considered base or alkali
a pH of about 7
a man-made chemical cleanser
filthy waste from household or industrial sources that is carried away in drains
a filter or purifier that removes impurities (particles and contaminants) from the air
something that contaminates our environment; can even be clean water that is too warm if it is drained into cool water and changes the habitat of animals there
acid rain
rain drops that have a pH of less than 5.6 because they have mixed with pollutants such as sulfur or nitrogen; can affect animals such as snails and birds by removing calcium from their habitat (calcium is needed to make snail shells and bird eggs)
tiny, solid particles such as dust, ash, soot, or pollen that are released into and move around in the air
polluted or dirty fog caused mainly by cars
photochemical smog
brown haze that contains ozone and blankets a city when car and truck exhaust react with sunlight
natural or man-made plant nutrient added to enhance plant growth; can cause problems (such as excessive algae growth) in streams or ponds if too much fertilizer runs off of yards or farms
Clean Water Act of 1977
Federal government regulation to restore and maintain the health and integrity of our nation's waters; requires communities to treat sewage before releasing it into a river
sulfur dioxide
air pollutant formed when fuel containing sulfur is burned; a colorless, irritating gas that contributes to formation of acid rain
thermal inversion: when a layer of warm air lies over cooler air near the ground, trapping pollutants
electrostatic separator
a machine used to separate substances by using electrical charges
Cuyahoga River
river located in northeast Ohio; when a layer of oil and debris (pollution) on its surface caught fire in 1969, our nation pain attention; concern over pollution causing the fire led to the Clean Water Act of 1977
carrying capacity
maximum population that the environment can support without negative effects
sanitary landfill
environmentally safe method of waste disposal where a landfill has a waterproof liner and is covered daily to keep harmful materials from entering the air and soil
to use a resource again
20th century
1900 through 1999
world population
total number of humans alive on the planet earth at a given time; the last 70 years of the 20th century saw the biggest increase in the world's population in human history
hazardous waste
solid, liquid, or gaseous material that is discarded and can harm people, animals or the environment; requires special disposal
use of plants to clean up polluted sites, usually by absorbing contaminants through their roots
way to recycle organic matter; by using natural processes, organic matter decomposes and becomes nutrient-rich soil builder
any substance that harms the environment when it mixes with soil, water or air
per capita
per person
an astronomical tool used to see distant objects such as those in space; first invented by Galileo in 1610
first artificial satellite; put into Earth's orbit in 1957 by the Soviets; led to creation of NASA and the race to the moon
Hubble Space Telescope
a telescope orbiting the Earth; its position outside the earth's atmosphere allows it to take sharp optical images of very faint objects
object that revolves around a planet
natural satellite of Earth
the path that an object makes around another object
U.S. space program that included 6 piloted moon landings between 1969 and 1972
Saturn rocket
rockets developed for the Apollo program to launch heavy payloads to Earth's orbit and beyond
Voyager space probes
two unmanned space probes: Voyager I and Voyager 2; launched in 1977; sent to study Jupiter and Saturn, went on to Uranus and Neptune, and then into the outer solar system
Spirit & Opportunity
twin robotic exploration rovers developed by NASA and sent to Mars in January 2003; these computers on wheels make observations and report them to NASA
Yuri Gagarin
Soviet cosmonaut (astronaut) who was the first human in space (1961)
John Glenn
first U.S. man to orbit Earth (1962)
Neil Armstrong
first man to walk on the moon (1969); an American
electromagnetic spectrum
entire range of electromagnetic radiation including: radio, microwave, infrared, visible light, ultraviolet, x-ray, and gamma ray radiation
space shuttle
reusable spacecraft that can carry a payload into orbit then return to Earth with its crew
space station
permanent laboratory and exploration platform in space
solar eclipse
the name of the event when the moon comes directly in between Earth and the sun and interrupts the light from the sun
having an oval shape, rounded like an egg
a piece of rock or metal that enters Earth's atmosphere but usually burns up before reaching Earth's surface
Gibbous moon
descriptive name for the moon when it is between a full moon and a half moon (more than half of the moon's surface is visible)
either of two days, usually March 21st or September 23rd, when daylight and darkness are about equal because the sun is directly over the Earth's equator
an imaginary straight line about which Earth rotates
one of two times during the year when the sun reaches its greatest distance from the equator during Earth's orbit, yielding the longest and shortest days of the year
SOHO mission
joint project between the European Space Agency (ESA) and NASA (US space agency) to investigate the sun
term used to describe the partial shadow that occurs during a lunar eclipse
North Pole
region of Earth that is a magnetic field because of Earth's rotation; magnetism causes a compass to point north
chunks of rock, pieces of planets, or small planets that primarily orbit the sun in an "asteroid belt" between Mars and Jupiter
Johannes Kepler
German astronomer best known for his laws of planetary motion
planet nearest the sun; smallest of the inner planets with no atmosphere and no moons
2nd planet from the sun; its atmosphere of mostly carbon dioxide traps heat from the surface, producing very high temperatures that lead to the Greenhouse effect on that planet
3rd planet from the sun; the planet we live on
4th planet from the sun, appears red due to iron oxide (rust) on its soil
5th planet from the sun, largest in our solar system with a Great Red Spot; has faint dust rings (that Voyager found) and many moons that include Europa, Ganymede, Callisto and Lo; Lo has active volcanoes
6th planet from the sun with large rings made mainly of ice and rock
7th planet from the sun, unusual because its axis is parallel to the plane of its orbit, not perpendicular like other planets
8th planet from the sun; methane gives Neptune its blue cloud color
9th planet from the sun; recently reclassified as a dwarf planet; Pluto is unusual in its orbit, some parts of Pluto's orbit are inside of Neptune's
a body in orbit around the sun
inner planets
the small, rocky planets that orbit closest to the sun including Mercury, Venus, Earth, and Mars
outer planets
planets that orbit far from the sun including Jupiter, Saturn, Uranus, Neptune and Pluto
light year
the distance traveled by a ray of light in one year
a cloud of gas and/or dust in space
medium size star that is at the center of our solar system; innermost layer is the core, then the photosphere, the chromosphere, and the corona
cooler dark spots on the photosphere of the sun; created when magnetic fields stop the circulation of gases
solar prominence
a large bright feature in the solar corona also influenced by magnetic fields
term used to describe the measure of a star's brightness
absolute magnitude
measurement of the brightness of a star as if it were a set distance away; allows overall brightness of objects to be compared without regard to distance from the earth
Milky Way
the spiral galaxy to which our sun and solar system belong
explosion caused when a massive star dies and collapses; rare, short-lived phenomenon that throws out vast amounts of energy into space; some so bright that they could be seen even in the middle of the day
star's energy source (in its core) where fusion of hydrogen to helium occurs
black hole
a completely collapsed dead star with a massive gravitational field so powerful that not even light can escape it
white dwarf
a "tiny" collapsed star about the size of a planet near the end of its nuclear fusion period; white and very hot
neutron star
a dense ball made up almost entirely of neutrons that remains after a supernova has exploded the rest of the star; extremely dense and more massive than our sun
Big Bang Theory
a theory of universe creation that assumes our universe began about 20 billion years ago with a super-powerful explosion