Ecology - Unit 5 Honors 23

Abiotic Factor

any nonliving factor in an organism's environment, such as soil, water, temperature, and light ability

Autotroph/Producer

Organism that captures energy from sunlight to produce its own food; provides the foundation of the food supply for other organisms.

Community

Group of interacting populations that live in the same geographic area at the same time.

Biomass

total mass of living matter at each trophic level

Biome

large group of ecosystems that share the same climate and have similar types of communities

Biosphere

The living parts of our planet

Biotic Factor

Any living factor in an organism's environment.

Carnivore

heterotroph that preys on other heterotrophs

Cell Theory

states that all organisms are made of cells, cells are the basic unit of life, and cells come from other cells.

Cellular Respiration

process through which the carbons in organic molecules (sugar) are broken down and released to the atmosphere in the form of carbon dioxide

Competition

Interaction among organisms that vie for the same resource in an ecosystem

Constants

a factor that remains the same during the experiment while the IV and DV change

Dependent Variable

factor that is measured in a controlled experiment. Also known as the effect.

Decomposer

heterotroph that breaks and absorbs organic material and returns nutrients to the soil, air, and water. Nutrients are recycled and can be used by the organisms at the producer level.

Ecology

scientific study of all the relationships between organisms and their environment

Ecosystem

a biological community and all the nonliving factors that affect it

Energy Flow

from the sun, to autotrophs, to heterotrophs, to decomposers

Food Chain

simplified model that shows a single path for energy flow through an ecosystem

Food Web

model that shows many interconnected food chains and pathways through which energy and matter flow through an ecosystem

Habitat

Physical area in which an organism lives

Herbivore

A heterotroph that eats only autotrophs

Heterotroph/Consumer

organism that CANNOT make its own food. must rely on feeding to obtain energy from other organisms.

Hypothesis

testable explanation of a situation. Must be an if/then statement that makes a prediction

Independent Variable

factor that is changed/tested by the scientist in a controlled experiment. The cause

Multicellular

describes an organism that is made of two or more cells

Nitrogen Fixation

process in which nitrogen gas is captured and converted into a form plants can use.

Nutrient Cycle

Continuous flow of nutrients into and out of stores in the ecosystem; balanced, unless disturbed by human activity

Omnivore

heterotroph that consumes both plants and animals

Organism

anything that has or once had all the characteristics of life

Photosynthesis

process in which carbon dioxide molecules from the atmosphere are transformed into biomass (carbohydrates) for a plant

Population

A group of individuals that belong to the same species and live in the same area

Scavenger

A carnivore that feeds on the bodies of dead organisms

Species

group of organisms that can interbreed and produce fertile offspring

Trophic Level

each step in a food chain or food web

Predation

Process by which one organism hunts and kills another organism for food.

Detritivore

An organism that eats dead plant and animal material

Geosphere

the rocks, sand, silt, soil of the planet Earth

Hydrocarbon

Fossil Fuel Compounds composed of only carbon and hydrogen

atmosphere

the mixture of gases that surround Earth

Biogeochemical Cycle

the circulation of nutrients through the atmosphere, biosphere, geosphere, and hydrosphere, also called nutrient cycle

control group

in an experiment, the group not receiving the independent variable

Experimental groups

in an experiments, the groups receiving varying degrees of the independent variable (e.g. the baggies with compost, the baggie with potting soil)

Hydrosphere

all of Earth's water

removal

Photosynthesis is responsible for \_______ of CO2 from the atmosphere

Emissions

combustion of fossil fuels and cellular respiration are both processes that contribute to carbon \_______ into the atmosphere

Conservation

The protection of natural resources

Keystone species

A species that influences the survival of many other species in an ecosystem

Mutualism

A relationship between two species in which both species benefit

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Ecological Succession

the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established

primary succession

An ecological succession that begins in an area where no biotic community previously existed

secondary succession

Succession following a disturbance that destroys a community without destroying the soil

climax community

A stable, mature community that undergoes little or no change in species over time

pioneer species

First species to populate an area during primary succession

sapling

a young tree

pyramid of energy

A pyramid that shows the total amount of energy available at each trophic level.

pyramid of numbers

shows the number of organisms at each trophic level

pyramid of biomass

Shows the total amount of living material available at each trophic level/ The area at the bottom corresponds to the producer level. It represents the greatest amount of living material.

resource partitioning

When species divide a niche to avoid competition for resources

fundamental niche

The full potential range of the physical, chemical, and biological factors a species can use if there is no competition from other species.

realized niche

Part of a species fundamental niche that it actually uses, limited by competition.

fundamental vs realized niche

The fundamental niche is where a species CAN live, negating the effects of predation, resource limitation, etc. The realized niche is where the species DOES live, because the factors mentioned above have forced it to retreat from parts of the fundamental niche.

competitive exclusion principle

Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time

Herbivory

interaction in which one animal (the herbivore) feeds on producers (such as plants)

Niche

An organism's particular role in an ecosystem, or how it makes its living.

Symbiosis

A close relationship between two species that benefits at least one of the species.

intraspecific competition

competition between members of the same species

interspecific competition

competition between members of different species

primary productivity

rate at which organic matter is created by producers in an ecosystem

exploitation competition

An interaction in which species compete indirectly through their mutual effects on the availability of a shared resource.