Life Sciences 11 - Ecology Test

Biosphere

The biosphere refers to the biological component of Earth’s systems.

Individual

A single organism.

Population

members of a species that all live in the same area.

Community

all of the population in a particular area.

Ecosystem

all living things and their physical environments within a particular area.

Biome

a large region characterized by a specific type of climate and certain types of plant and animal communities.

Species

A group of organisms capable of interbreeding and producing fertile offspring.

Biodiversity

 The variety of life in the world or in a particular habitat or ecosystem.

Abiotic Factors

Non-living physical and chemical elements in an ecosystem.

Biotic Factors

 Living or once-living components of an ecosystem.

Habitat

The natural home or environment of an animal, plant, or other organism.

Succession

The gradual process by which an ecosystem changes over time.

Primary succession

Succession that occurs in an area where no soil or life previously existed.

Secondary Succesion

Succession that occurs in an area where an existing community has been removed, but soil remains.

Biomass

The total mass of organisms in a given area or volume.

Producer

An organism that produces its own food (e.g., plants, algae).

Primary consumer

An organism that feeds on producers (herbivore).

Secondary consumer

An organism that feeds on primary consumers (carnivore or omnivore).

Tertiary consumer

An organism that feeds on secondary consumers (carnivore or omnivore).

Herbivoire

An animal that feeds on plants.

Carnivore

An animal that feeds on other animals.

Omnivore

An animal that feeds on both plants and animals.

Detrivore

An organism that feeds on dead organic matter.

Decomposer

An organism that breaks down dead organic material; a detritivore.

Trophic levels

The successive levels of organisms in a food chain, based on their feeding position.

Food chain

A linear sequence showing how energy is transferred from one organism to another.

Food web

A network of interconnected food chains in an ecosystem.

Ten Percent Rule

Only about 10% of the energy from one trophic level is transferred to the next.

Population size

The total number of individuals in a population.

Population density

The number of individuals per unit area or volume.

Exponential growth

Population growth that occurs when resources are unlimited, resulting in a J-shaped curve.

Logistic growth

Population growth that is limited by resources, resulting in an S-shaped curve as it approaches carrying capacity.

Pioneer species

The first species to colonize a barren or disturbed area.

Food pyramid

A graphical representation showing the distribution of biomass or energy at each trophic level.

Carrying capacity

The maximum population size that an environment can sustain indefinitely.

Density dependent

Factors that limit population growth more strongly as population density increases (e.g., disease, competition).

Density independent

Factors that limit population growth regardless of population density (e.g., natural disasters, climate change).

Bioaccumulation

The accumulation of substances, such as pesticides, or other chemicals in an organism.

Biomagnification

The increasing concentration of a substance, such as a toxic chemical, in the tissues of organisms at successively higher levels in a food chain.

Niche

The role and position a species has in its environment; how it meets its needs for food, shelter, and reproduction.

Predation

 An interaction where one organism (predator) kills and consumes another organism (prey).

Competition

: An interaction between organisms in which both are harmed, as both seek the same limited resource.

Parasitism

A relationship where one organism (parasite) benefits by living on or in another organism (host), harming it.

Mutalism

A symbiotic relationship in which both organisms benefit.

Commensalism

A symbiotic relationship in which one organism benefits and the other is neither harmed nor helped.