The portion of the ocean floor where light does not penetrate and where temperatures are cold and pressures intense.
Age Structure Graph
proportion of people in different age groups in a population
A small, very toxic molecule (NH3) produced by nitrogen fixation or as a metabolic waste product of protein and nucleic acid metabolism.
Layers of air surrounding the earth.
Organisms that are able to make their own food
Normal extinction of various species as a result of changes in local environmental conditions.
the steep descent of the seabed from the continental shelf to the abyssal zone
bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms
organisms (plants and animals) that live at or near the bottom of a sea
carbon, nitrogen, sulfur, water cycles, process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
Plant materials and animal waste used especially as a source of fuel.
a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.
Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.
Maximum rate at which the population of a given species can increase when there are no limits on its rate of growth.
the number of births in a population in a certain amount of time
Plants that keep most of their broad leaves year-round. Examples are the trees found in the canopies of tropical rain forests.
Consumers that eat only animals
Largest number of individuals of a population that a environment can support
Overall weather in an area over a long period of time
A relationship between two organisms of different species where one benefits and the other is neither harmed nor benefited
Competitive Exclusion Principal
Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time
Cone-bearing plants (such as spruces, pines, and firs) that keep some of their narrow, pointed leaves (needles) all year.
A plate boundary where two plates move toward each other
Cultural Carrying Capacity
the maximum number of people who could live in reasonable freedom and comfort indefinitely, without decreasing the ability of the earth to sustain future generations.
an increase in biological productivity and ecosystem succession caused by human activities
Mass movements of surface water produced by prevailing winds blowing over the oceans.
The number of deaths in a population in a certain amount of time
Bacteria that break down nutrients in dead matter into simpler substances
Change in a population from high birth and death rates to low birth and death rates
Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.
organism that feeds on plant and animal remains and other dead matter
A sudden population decline; also called a population crash
A plate boundary where two plates move away from each other
percent of biomass in one trophic levelthat is converted into biomass in the next highest level
Scientific study of interactions among organisms and between organisms and their environment
A periodic change in the pattern of ocean currents and water temperature in the mid-pacific region
Migration from a location
A species whose numbers are so small that the species is at risk of extinction
species that are native to and found only within a limited area
All the limiting factors that tend to reduce population growth rates and set the maximum allowable population size or carrying capacity of an ecosystem
Upper layer of a body of water through which sunlight can penetrate and support photosynthesis.
Lake with a large or excessive supply of plant nutrients, mostly nitrates and phosphates.
A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria.
Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.
organisms that are not native to a particular area
Growth pattern in which the individuals in a population reproduce at a constant rate
a severe shortage of food (as through crop failure) resulting in violent hunger and starvation and death
First Law of Thermodynamics
Heat is a form of energy which can be neither created nor destroyed but can be changed in form
Species that plays a major role in shaping communities by creating and enhancing a habitat that benefits other species.
Species with a broad ecological niche. They can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions. Examples are flies, cockroaches, mice, rats, and human beings. Compare specialist species.
A change in the allele frequency of a population as a result of chance events rather than natural selection.
Process of making changes in the DNA code of living organisms
form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water
An increase in the average temperature of the earth’s atmosphere (especially a sustained increase that causes climatic changes)
Natural situation in which heat is retained in Earth’s atmosphere by carbon dioxide, methane, water vapor, and other gases
Place where an organism lives
An organism that eats only plants.
An organism that obtains organic food molecules by eating other organisms or their by-products.
All the water at and near the surface of the earth, 97% of which is in oceans
intrusive or extrusive rock that is produced when melted rock from inside Earth cools and hardens
Migration to a new location
Species that serve as early warnings that a community or ecosystem is being degraded.
Infant Mortality Rate
the death rate during the first year of life
water on the ground surface enters the soil
Competition between members of different species
Competition among members of the same species
A species that influences the survival of many other species in an ecosystem
reproduce late in life; few offspring; care for offspring
A cooling of the ocean surface off the western coast of South America, occurring periodically every 4 to 12 years and affecting Pacific and other weather patterns.
Law of Conservation of Matter
Matter is neither created nor destroyed
Small raised areas in the bark of stems and roots that enable gas exchange between living cells and the outside air.
A figure indicating how long, on average, a person may be expected to live. Normally expressed in the context of a particular state.
area in a freshwater habitat away from the shore but still close to the surface
Expansion that increases by the same amount during each time interval.
A rigid layer made up of the uppermost part of the mantle and the crust.
a shallow zone in a freshwater habitat where light reaches the bottom and nurtures plants
Growth pattern in which a population’s growth rate slows or stops following a period of exponential growth
when many species become extinct in one period of time
Lakes with moderate amounts of nutrients and phytoplankton productivity intermediate to oligotrophic and eutrophic systems.
A type of rock that forms from an existing rock that is changed by heat, pressure, or chemical reactions.
Ability of an animal to look like another more harmful animal
(genetics) any event that changes genetic structure
A relationship between two species in which both species benefit
Species that normally live and thrive in a particular ecosystem
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
Negative Feedback Loop
A feedback loop that causes a system to change in the opposite direction from which it is moving
All organisms that swim actively in open water, independent of currents
Net Primary Producer
the amount of energy (per unit of time) that producers fix by photosynthesisor other means, minus the amount they use in cellular respiration
Full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
Special compounds containing nitrogen and oxygen
Form in which nitrogen may be found in the soil. Chemical formula NO2
Process of converting nitrogen gas into ammonia
a resource that cannot be reused or replaced easily (ex. gems, iron, copper, fossil fuels)
a condition of a lake or other body of water characterized by low nutrients, low productivity, and high oxygen levels in the water column.
An organism that eats both plants and animals.
A relationship between two organisms of different species where one benefits and the other is harmed
Ability of rock or soil to allow water to flow through it
A process by which plants make their own food
Microscopic, free-floating, autotrophic organisms that function as producers in aquatic ecosystems
The theory that pieces of Earth’s lithosphere are in constant motion, driven by convection currents in the mantle.
Addition of more waste than a resource can accommodate.
Population Growth Rate
rate of natural increase
The percentage of the total volume of a rock or sediment that consists of open spaces.
Positve Feedback Loop
only a few examples in human body, the stimulus doesn’t produce an opposite and counteracting effect
succesion that begins at a place where there had been no life before
Make their own food from compounds obtained from their environment
zone in a freshwater habitat that is below the limits of effective light penetration
Rain Shadow Effect
Precipitation falls on the windward side of a mountain range, resulting in lush vegetation & a warm, moist climate on one side, but a desert area on the leeward side.
Any natural resource (as wood or solar energy) that can be replenished naturally with the passage of time
the number of children a couple must have to replace themselves (2.1 developed, 2.7 developing)
Separation of species or populations so that they cannot interbreed and produce fertile offspring
strength; ability to withstand
A substance in the environment that is useful to people, is economically and technologically feasible to access, and is socially acceptable to use.
The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species
A symbiotic bacterium that lives in the nodules on roots of specific legumes and that incorporates nitrogen gas from the air into a form of nitrogen the plant requires
Species characterized by rapid growth, high fertility, short lifespan, and exponential population growth
A process in which mineral salts accumulate in the soil, killing plants; occurs when soils in dry climates are irrigated profusely
Second law of Thermodynamics
thermal energy that flows from a warmer material to a cooler material
A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together
Movement of soil components, especially topsoil, from one place to another, usually by wind, flowing water, or both. This natural process can be greatly accelerated by human activities that remove vegetation from soil.
The layer of soil that differs in color and texture from the layers above or below it.
All the vertical layers or horizons that make up a soil in a particular place
Species with a narrow ecological niche. They may be able to live in only one type of habitat, tolerate only a narrow range of climatic and other environmental conditions, or use only one type or a few types of food.
Formation of new species
the relative abundance of each species
The number of different species in a community
The region where oceanic plates sink down into the asthenosphere.
full of juice or sap. thick, fleshy, waterstoring leaves. highly interesting or enjoyable. (In the desert, most of the leaves are very succulent because water is scarce.)
Survival of the Fittest
Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called natural selection
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
Interaction of two or more factors or processes so that the combined effect is greater than the sum of their separate effects
the time at which a change or an effect cannot be stopped
Total Fertility Rate
The number of children born to an average woman in a population during her entire reproductive life
Tragedy of the Commons
A parable that illustrates why common resources are used more than is desirable from the standpoint of society as a whole- Garrett Hardin
A plate boundary where two plates move past each other in opposite directions
The hierarchical levels of the food chain through which energy flows from primary producers to primary consumers, secondary consumers and so on.
much smaller plankton, photosynthetic bacteria may be responsible for 70% of the primary productivity near the ocean surface.
The movement of deep, cold, and nutrient-rich water to the surface
Conditions in the atmosphere closest to Earth
Zero Population Growth
A decline of the total fertility rate to the point where the natural increase rate equals zero.
microscopic animals that swim or drift near the surface of aquatic environments