Unit 6

Vocabulary Review

Ecosystem

• A community and the abiotic factors that affect them.

Stable Ecosystem

• The fluctuations in populations and resources at a predictable rate.

Predation

• An interaction between species in which one species eats the other.

Predator

• A species that eats another.

Prey

• The species that is eaten by another.

Competition

• A relationship that occurs when two or more organisms need the same resource at the same time.

Niche

• The area in which organisms live and reproduce, and the role they play.

Symbiotic Relationships

• A relationship that exists between organisms of two different species that live together in direct contact.

Parasitism

• A relationship in which one organism benefits at the expense of the other organism.

Mutualism

• A relationship in which both organisms benefit.

Commensalism

• A relationship in which one organism benefits and the other organism is not affected

Population

• A group of organisms belonging to the same species that live in a particular area.

Population Density

• Measures the number of individual organisms living in a defined space

Limiting Factors

• Regulations that affect a population.

Density-dependent

• Factors that operate more strongly on large populations than on small ones, which include competition, predation, parasitism, and disease; and are triggered by increases such things as crowding.

Density-independent

• Factors that occur regardless of how large the population is and reduce the size of all populations in the area in which they occur by the same proportion, such as pollution and fires.

Abiotic

• Nonliving factors in a population such as chemicals, water, soil, etc.

Biotic

• The living components of an ecosystem such as bacteria, fungi, plants, and animals.

Ecological Succession

• The series of changes in an ecosystem when one community is replaced by another community as a result of changes in abiotic and biotic factors.

Primary Succession

• Succession that occurs in an area that has not previously been inhabited.

Pioneer Species

• The first organisms in an ecosystem.

Climax Community

• A mature community that results where there is little change in the composition of species and maintains itself as long as no disturbances occur.

Secondary Succession

• An area where there was a preexisting community and well-formed soil.

Geochemical Cycles

• The movement of a particular form of matter through the living and nonliving parts of an ecosystem.

Carbon Cycle

• The movement of carbon through the living and nonliving parts of an ecosystem

Nitrogen Cycle

• The movement of nitrogen through the living and nonliving parts of an ecosystem.

Elemental Nitrogen

• The form that nitrogen is found in the atmosphere.

Nitrogen Fixation

• The process of converting nitrogen found in the air or dissolved in water into the forms that are available for use by plants.

Denitrifying Bacteria

• Organisms that break down the nitrogen compounds in the soil and release elemental nitrogen into the atmosphere.

Water Cycle (hydrologic cycle)

• The movement of water through the ecosystem so that it may be reused over and over.

Atmosphere

• The result of the life processes of the organisms which inhabit Earth, and consists of gases.

Ozone Layer

• Oxygen gases in the atmosphere and prevents much of the Sun’s ultraviolet radiation from reaching Earth’s surface and protects the biosphere from the harmful radiation.

Greenhouse Effect

• The normal warming effect when gases trap heat in the atmosphere.

Sink

• The process of absorbing what plants do not use and converting it to various salts such as calcium carbonate.

Geosphere

• The densest part of the Earth that contains rock and soil.

Soil Erosion

• Natural processes that move soil from one location to another due to water, wind, ice and other agents.

Deposition

• A process where soil erosion stops when the transported particles finally fall out of the transporting medium and settle on a surface due to the laying down of sediment, which are transported by wind, water, or ice.

Carrying Capacity

• The maximum population size that can be supported by the available resources.

Sustainability

• The process of the ecosystem to meet the needs of humans to survive indefinitely.

Population Growth

• An increase in the number of organisms in an ecosystem.

Technology

• Applied scientific knowledge in order to either find solutions to problems or develop products to help meet the needs of humans.

Consumption of Resources

• When organisms use resources.

Agricultural

• The process of farming to cultivate life forms for food, fiber, and other products used to sustain life

Industrial

• The production of an economic good or service within an economy, such as automobile or steel.

Alternative Energy

• Another form to produce usable energy other than the methods that are already available.

Renewable Resources

• Resources that can be produced at roughly the same rate that they are consumed, such as food, clean water, and timber.

Nonrenewable Resources

• Resources that cannot be produced at the same rate that they are consumed, such as fossil fuels.