Scientific data
facts collected by making observations and measurements
Scientific hypotheses
a variety of possible or tentative explanations of what is observed in nature
Model
an approximate representation or simulation of a system being studied
Scientific theory
a verified, highly reliable, and widely accepted scientific hypothesis or a related group of scientific hypotheses
Scientific/natural law
a description of what we find happening in nature over and over in the same way
Scientific method
ways scientists gather data and formulate and test scientific hypotheses, models, theories, and laws
Inductive reasoning
involves using specific observations and measurements to arrive at a general conclusion or hypothesis
Deductive reasoning
involves using logic to arrive at a specific conclusion based on a generalization or premise
Frontier science
preliminary results that have not been widely tested and accepted
Consensus science
consists of data, theories, and laws that scientists who are considered experts in the field involved widely accept
System
a set of components that function and interact in some regular and theoretically predictable manner and can be isolated for the purpose of observation and study
Inputs
matter, energy, or information put into the system
Flows/throughputs
matter, energy, or information within the system at certain rates
Stores/storage areas
within a system where matter, energy, or information can accumulate for various lengths of time before being released
Outputs
certain forms of matter, energy, or information that flow out of the system into sinks in the environment
Feedback loop
occurs when an output of matter, energy, or information is fed back into the system as a input that changes the system
Positive feedback
a change in a certain direction provides information that causes a system to change further in the same direction
Negative feedback
one change leads to a lessening of that change
Time delays
the time between the input of a stimulus and the response to it
Synergistic interaction
occurs when two or more processes interact so that the combined effect is greater than the sum of their separate effects
Synergy
can result when two people work together to accomplish a task
Matter
anything that has mass (the amount of material in an object) and takes up space
Elements
the distinctive building blocks of matter that make up every material substance
Compounds
two or more different elements held together in fixed proportions by attractive forces called chemical bonds
Mixtures
various elements, compounds, or both
Atoms
the smallest units of matter that are unique to a particular element
Ions
electrically charged atoms or combinations of atoms
Molecules
combinations of two or more atoms of the same or different elements held together by chemical bonds
Proton
positively charged
Neutron
uncharged
Electron
negatively charged
Nucleus
extremely small center of an atom
Atomic number
the number of protons
Mass number
the total number of neutrons and protons
Isotopes
various forms of an element having the same atomic number but a different mass number
Concentration
the amount of substance in a unit volume or air, water, or other medium
Chemical formula
contains the symbols for each of the elements present and use subscripts to represent the number of atoms or ions of each element in the compound's basic structural unit
Organic compounds
contain carbon atoms combined with each other and with atoms of one or more other elements
Genes
consist of specific sequences of nucleotides in a DNA molecule
Chromosomes
combinations of genes that make up a single DNA molecule, together with a number of proteins
Inorganic compounds
do not have carbon-carbon or carbon-hydrogen covalent bonds
Plasma
a high energy mixture of roughly equal numbers of positively charged ions and negatively charged electrons
High-quality matter
concentrated, usually is found near the earth's surface, and has great potential for use as a matter resource
Low-quality matter
diluted, often is deep underground, and usually has little potential for use as a matter resource
Material efficiency/resource productivity
the total amount of material needed to produce each unit of goods or services
Radiation
the transmission of energy through space as particles or waves
Kinetic energy
matter has because of its mass and its speed or velocity
Potential energy
is stored and potentially available for use
Electromagnetic radiation
energy radiated in the form of a wave as a result of the changing electric and magnetic fields
Ionizing radiation
has enough energy to knock electrons from atoms and change them to positively charged ions
Non-ionizing radiation
do not contain enough energy to form ions
Temperature
the average speed of motion of the atoms, ions, and molecules in a sample of matter at a given moment
Convection
the transfer of heat by the movement of heated material
Conduction
the transfer of heat by collisions of atoms or molecules
Radiation
the transfer of heat by wave motion
Energy quality
a measure of an energy source's ability to do useful work
High-quality energy
concentrated and can perform much useful work
Low-quality energy
dispersed and has little ability to do useful work
Physical change
involves no change in chemical composition
Chemical change/chemical reaction
the chemical compositions of the elements or compounds are altered
Law of conservation of matter
matter cannot be created or destroyed and there's no "away
Persistence
how long something stays in the air, water, soil, or body
Degradable/nonpersistent pollutants
pollutants broken down completely or reduced to acceptable levels by natural, physical, chemical, and biological processes
Biodegradable pollutants
complex chemical pollutants that living organisms (usually specialized bacteria) break down (metabolize) into simpler chemicals
Slowly degradable/persistent pollutants
pollutants that take decades or longer to degrade
Nondegradable pollutants
pollutants that cannot be broken down by natural processes
Nuclear change
occurs when nuclei of certain isotopes spontaneously change or are made to change into one or more different isotopes
Natural radioactive decay
a nuclear change in which unstable isotopes spontaneously emit fast-moving chunks of matter (called particles), high-energy radiation, or both at a fixed rate
Radioactive isotopes/radioisotopes
unstable isotopes
Gamma rays
a form of high-energy electromagnetic radiation
Alpha particles
fast-moving, positively charged chunks of matter that consist of two protons and two neutrons
Beta particles
high-speed electrons
Half-life
the time needed for one-half of the nuclei in a radioisotope to decay and emit their radiation to form a different isotope
Nuclear fission
a nuclear change in which nuclei of certain isotopes with large mass numbers are split apart into lighter nuclei when struck by neutrons
Critical mass
amount of fissionable nuclei needed to sustain a nuclear fission reaction
Chain reaction
formed by multiple fissions within a critical mass
Nuclear fusion
a nuclear change in which two isotopes of light elements are forced together at extremely high temperatures until they fuse to form a heavier nucleus, releasing energy in the process
Law of conservation of energy/ first law of thermodynamics
in all physical and chemical change, energy is neither created nor destroyed, but it may be converted from one form to another
Second law of thermodynamics
when energy is changed from one form to another, some of the useful energy is always degraded to lower quality, more dispersed, less useful energy
Energy efficiency/energy productivity
a measure of how much useful work is accomplished by a particular input of energy into a system
High-throughput (high-waste) economy
situation in most advanced, industrialized countries where resource use is high
Matter-recycling economy
allows economic growth to continue without depleting matter resources or producing excessive pollution and environmental degradation
Low-throughput (low-waste) economy
economy based on working with nature
Organism
any form of life
Cell
basic unit of life in organisms
Eukaryotic
has cells surrounded by a membrane, has a distinct nucleus, and several other internal parts called organelles (all organisms except bacteria)
Prokaryotic
has cells surrounded by a membrane, but no distinct nucleus or other internal parts (bacteria)
Asexual reproduction
common in species such as bacteria, which divides to produce two identical cells that are clones or replicas of the original cell
Sexual reproduction
occurs in organisms that produce offspring by combining sex cells or gametes (such as ovum and sperm) from both parents
Population
consists of a group of interacting individuals of the same species that occupy a specific area at the same time
Genetic diversity
the variation of individuals in their genetic makeup
Habitat
the place where a population (or an individual organism) normally lives
Biological community
a complex interacting network of plants, animals, and microorganisms
Ecosystem
a community of different species interacting with one another and with their nonliving environment of matter and energy
Atmosphere
a thin envelope or membrane of air around the planet
Troposphere
inner layer of the atmosphere; extends about 17 kilometers above sea level and contains most of the planet's air
Stratosphere
layer above the troposphere, stretching 17-48 kilometers above the earth's surface
Hydrosphere
consists of the earth's liquid water, ice, and water vapor in the atmosphere
Lithosphere
the earth's crust and upper mantle
Biosphere
the portion of the earth in which living (biotic) organisms exist and interact with one another and their nonliving (abiotic) environment
Natural greenhouse effect
the atmosphere helping to warm the earth, which allow a buildup of heat
Biomes
regions characterized by a distinct climate and specific life-forms adapted to it
Climate
long-term patterns of weather
Aquatic life zones
aquatic equivalent of biomes
Ecotone
a region containing a mixture of species from adjacent ecosystems and often species not found in either of the bordering ecosystems
Abiotic
nonliving
Biotic
living
Range of tolerance
how much variation in its physical and chemical environment each population in an ecosystem can endure
Law of tolerance
the existence, abundance, and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species
Limiting factor
important in regulating population growth
Limiting factor principle
too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimum range of tolerance
Dissolved oxygen (DO) content
the amount of oxygen gas dissolved in a given volume of water at a particular temperature and pressure
Salinity
the amounts of various inorganic minerals or salts dissolved in a given volume of water
Producers/ autotrophs
make their own food from compounds obtained from their environment
Photosynthesis
carob dioxide + water + solar energy = glucose + oxygen
Chemosynthesis
conversion of simple compounds from the producers' environment into more complex nutrient compounds without sunlight
Consumers/ heterotrophs
get their energy and nutrients by feeding on other organisms or their remains
Herbivores/ primary consumers
feed directly on producers
Carnivores/ secondary consumers
feed on other consumers
Tertiary (high-level) consumers
those feeding on other carnivores
Omnivores
eat plants and animals
Scavengers
feed on dead organisms
Detritivores
feed on detritus
Detritus
parts of dead organisms and cast-off fragments and wastes of living organisms
Detritus feeders
extract nutrients from partly decomposed organic matter in leaf litter, plant debris, and animal dung
Decomposers
recycle organic matter in ecosystems by breaking down dead organic material to get nutrients and releasing the resulting simpler inorganic compounds into the soil and water
Aerobic respiration
uses oxygen to convert organic nutrients back into carbon dioxide and water
Anaerobic respiration/ fermentation
instead of carbon dioxide and water, the end products of this process are compounds such as methane gas, ethyl alcohol, acetic acid, and hydrogen sulfide
Biological diversity/ biodiversity
the different life-forms and life-sustaining processes that can best survive the variety of conditions currently found on the earth
Genetic diversity
variety in the genetic makeup among individuals within a species
Species diversity
variety among the species or distinct types of living organisms found in different habitats of the planet
Ecological diversity
variety of forests, deserts, grasslands, streams, lakes, oceans, coral reefs, wetlands, and other biological communities
Functional diversity
biological and chemical processes or functions such as energy flow and matter cycling needed for the survival of species and biological communities
Food chain
determines how energy and nutrients move from one organisms to another though an ecosystem
Trophic level
feeding level
Food web
complex network of interconnected food chains
Biomass
the dry weight of all organic matter contained in a trophic level's organisms
Ecological efficiency
the percentage of usable energy transferred as biomass from one trophic level to the next
Pyramid of energy flow
diagram representing the flow of energy through each trophic level in a food chain or food web
Pyramid of numbers
diagram representing the number of organisms of a particular type that can be supported at each trophic level
GPP
(Gross Primary Productivity) the rate at which an ecosystems's producers convert solar energy into chemical energy as biomass
NPP
(Net Primary Productivity) the rate at which producers store chemical energy as biomass (through photosynthesis) minus the rate at which producers use chemical energy stored as biomass (through aerobic respiration)
Nutrient cycles/ biogeochemical cycles
natural process that recycle nutrients in various chemical forms from the nonliving environment to living organisms and then back to the nonliving environment
Hydrologic cycle/ water cycle
collects, purifies, and distributes the earth's fixed supply of water
Absolute humidity
the amount of water vapor found in certain mass of air adn is usually expressed in grams of water per kilogram of air
Relative humidity
the amount of water vapor in a certain mass of air, expressed as a percentage of the maximum amount it could hold at that temperature
Condensation nuclei
tiny particles on which droplets of water vapor can collect
Dew point
the temperature at which condensation occurs
Carbon cycle
cyclic movement of carbon in different chemical forms from the environment to organisms and then back to the environment
Ecosystem services
natural services or natural capital that support life on the earth and are essential to the quality of human life and the functioning of the world's economies