Chapter 6

LS Biology

Habitat

area where an organism lives including the biotic and abiotic factors that affect it

Tolerance

ability of an organism to survive and reproduce under circumstances that differ from their optimal conditions

niche

full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions

resource

refers to any necessity of life, such as water, nutrients, light, food, or space. Ex. key question

competitive exclusion principle

principle that states no two species can occupy the same niche in the same habitat at the same time

keystone species

single species that is not usually abundant in a community yet exerts strong control on the structure of a community

Symbiosis

any relationship in which two species live closely together

Commensalism

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

Mutualism

symbiotic relationship in which both species benefit from the relationship

Parasitism

symbiotic relationship in which on organism lives on or inside another organism and harms it

ecological succession

series of gradual changes that occur in a community following a disturbance

Primary succession

succession that occurs in an area in which no trace of a previous community is present

Pioneer species

first species to populate an area during succession

Secondary succession

type of succession that occurs in an area that was only partially destroyed by disturbance

biodiversity

the total of the variety of organisms in the biosphere; also called biological diversity

ecosystem diversity

variety of habitats, communities, and ecological processes in the biosphere

species diversity

number of different species that makes up a particular area

genetic diversity

sum total of all the different forms of genetic information carried by a particular species, or by all organisms on Earth

resilience

a natural or human system's ability to recover after a disturbance

ecosystem services

the benefits provided by ecosystems to humans