Bio unit B definitions

ecotone

 A transition area where two different ecosystems meet and mix.

Biodiversity

 The variety of living organisms in an area.

Niche

The role or job of a species in its ecosystem, including what it eats, where it lives, and how it interacts with others.

Exotic species

A species that is not native to an area; it was introduced by humans.

Biome

A large area with a specific climate, plants, and animals (e.g., desert, forest, tundra).

Aquatic ecosystem

An ecosystem found in water, like lakes, rivers, or oceans.

taiga

 A cold forest biome with mostly coniferous trees (also called boreal forest).

boreal forest

Another name for the taiga; found in northern regions with cold climates.

deciduous forest

 A forest where trees lose their leaves in the fall.

grassland

A biome with mostly grasses and few trees; often found in prairies or savannas.

muskeg

A type of wetland with spongy soil, moss, and slow-decaying plants; found in cold regions.

permafrost

 Soil that remains frozen all year round.

Freshwater ecosystem

 An ecosystem in water with little or no salt, like rivers, lakes, or ponds.

lake ecosystem

 A freshwater ecosystem found in a lake.

chemical environment

 The chemical conditions in a habitat, like pH, oxygen, and nutrient levels.

water pressure

The force of water exerted on organisms, which increases with depth.

littoral zone

 The shallow area near the shore of a lake where light reaches the bottom and plants can grow.

limnetic zone

The open water area of a lake where light penetrates but not to the bottom.

benthic zone

 The bottom of a lake or other body of water, where organisms live on or in the soil.

profundal zone

The deep part of a lake where no sunlight reaches and oxygen is low.

biotic potential

The maximum number of offspring a species can produce under ideal conditions.

capacity for survival

How many individuals can survive and grow to reproduce.

breeding frequency

 How often an organism reproduces in a given time.

length of reproductive life

How long an organism can reproduce in its lifetime.

birth potential

The number of offspring an organism can produce each time it reproduces.

limiting factors

Things that prevent a population from growing too large (e.g., food, space, predators).

density-independent factors

Limiting factors that affect a population regardless of its size (e.g., natural disasters, temperature).

density-dependent factors

Limiting factors that depend on the population size (e.g., competition, disease).

interspecies competition

When individuals of different species compete for the same resources.

intraspecies competition

When individuals of the same species compete for resources.

symbiosis

A close relationship between two different species.

commensalism

 A symbiotic relationship where one benefits and the other is not affected.

mutualism

A symbiotic relationship where both species benefit.

parasitism

 A symbiotic relationship where one species benefits and the other is harmed.

carrying capacity

The maximum number of individuals an environment can support long-term.

Terrestrial ecosystem

An ecosystem found on land, like forests or grasslands.

invasive species

 An exotic species that spreads quickly and harms the native ecosystem.