U7: Ecology Review

scavenger

A carnivore that feeds on the bodies of dead organisms usually killed by a predator

genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection

food web

A community of organisms where there are several interrelated food chains

Carnivore

A consumer that eats only animals.

Herbivore

A consumer that eats only plants.

Biome

A group of ecosystems that share similar climates and typical organisms

Population

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

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

Mutualism

A relationship between two species in which both species benefit

food chain

A series of steps in which organisms transfer energy by eating and being eaten

climax community

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

Community

All the different populations that live together in an area

Omnivore

An animal that eats both plants and animals

predator

An animal that hunts other animals for food

primary succession

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

population growth

An increase in population over a period of time.

Predation

An interaction in which one organism kills another for food.

secondary consumer

An organism that eats primary consumers

primary consumer

An organism that eats producers

tertiary consumer

An organism that eats secondary consumers

prey

An organism that is killed and eaten by another organism

Autotroph

An organism that makes its own food

Niche

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

limiting factor

Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.

quaternary consumer

Carnivore that eats tertiary consumers.

trophic level

Each step in a food chain or food web

pioneer species

First species to populate an area during primary succession

exponential population growth

Growth of a population in an ideal, unlimited environment, represented by a J-shaped curve

predator-prey relationship

Interaction between two organisms of different species in which one organism, called the predator, captures and feeds on parts or all of another organism, called the prey.

carrying capacity

Largest number of individuals of a population that a environment can support

habitat

Place where an organism lives

photic zone

Portion of the marine biome that is shallow enough for sunlight to penetrate.

native species

Species that normally live and thrive in a particular ecosystem

secondary succession

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

water cycle

The continuous process by which water moves from Earth's surface to the atmosphere and back

Ecology

The study of how living things interact with each other and their environment

nitrogen cycle

The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere

Desert Biome

a biome that has little or no plant life, long periods without rain, and extreme temperatures; usually found in hot climates

tropical rain forest biome

a forest or jungle that is characterized by large amounts of rain and little variation in temperature and that contains the greatest known diversity of organisms

individual

a single organism

age structure diagram

a visual representation of the number of individuals within specific age groups that can be used to predict population growth rates

Energy loss in food chain

about 90% of the energy taken is lost through respiration and waste

marine biome

aquatic biome in the salt water of the ocean

Symbiosis

close and permanent association between two species

Hardy-Weinberg equilibrium

condition in which a population's allele frequencies for a given trait do not change from generation to generation; rarely found in real life

taiga biome

coniferous forests that have long, cold winters. the trees have needles instead of broad leaves.

phosphurus cycle

cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere

aphotic zone

dark layer of the oceans below the photic zone where sunlight does not penetrate

tundra biome

extremely cold and dry biome; known for its permafrost, mosses, lichens, caribou, and snowy owl

density dependent factors

factor that limits a population more as population density increases

linear population growth

growth that proceeds at the same rate over time

competition for resources

increasing population density intensifies competition for resources and results in lower birth rate

freshwater biomes

lakes, ponds, rivers, streams and wetlands

Grassland Biome

land biome characterized by moderate rainfall, fields of grasses, and few trees

density-independent factors

limiting factor that affects all populations in similar ways, regardless of population size; usually abiotic factors such as storms and human impact)

temperate forest biome

made of a mix of deciduous and evergreen trees. fertile soils with rich humus layers. 4 seasons with warm summers and cold winters

gene flow

movement of alleles from one population to another

nonnative/invasive species

non-native species that are intentionally or accidentally introduced to an ecosystem

Heterotroph

organism that obtains energy from the foods it consumes; also called a consumer

Biosphere

part of Earth in which life exists including land, water, and air or atmosphere

logistic population growth

population growth that levels off as population size approaches carrying capacity

detritivores/decomposers

recycle nutrients within the ecosystem by breaking down nonliving organic matter

food web vs food chain

the food web is more accurate than the food chain because with the food web, you can see multiple animals/plants that eat or are eaten by another, while the food chain just shows one organism eats one more, which eats another, which eats another, and so on

carbon cycle

the movement of carbon from the nonliving environment into living things and back

ecological succession

the predictable replacement of one group of species by another group of species over time

overcrowding

too many individuals, not enough space