Unit 5- Lions Test

Organism

Individual living thing

Ecology

The study of how organisms interact with each other and with their environment

Population

all the individuals of the same species living in a defined area

Habitat

a defined area where a species lives

Community

All living organisms living close enough together for potential interactions

ecosystem

includes both the biotic and abiotic factors of the environment

biotic factors

living factors of an environment

abiotic factors

non-living factors of an environment

biosphere

every place on earth that is inhabited by life

autotrophs

“self-feeders”/ make their own organic nutrients using external energy sources/ also called producers

heterotroph

“Different feeder”/obtain organic nutrients from other organisms, also called consumers

Food chain

linear sequence of matter and energy flow through an ecosystem. Arrows point in the direction of flow

food web

a network of interconnected food chains

decomposers

feed on all trophic levels, convert organic matter into inorganic matter

10% rule

as you move from one tropic level to the next, only 10% of the energy at one level is available at the next. This means that 90% of energy is lost as heat or metabolic process

niche

role of an organism in its habitat

keystone species

plays an especially important role in its community/ if removed, has drastic effects

predators

help control prey populations, which in turn affects other trophic levels

ecosystem engineers

create, destroy, or change a habitat

mutualists

two or more species who interact with each other for each other’s benefits

population size

number of individuals in a population

population density

the average number of individuals in a population per unit of area or volume

population distribution

average number of individuals per unit of area or volume

limiting factors

density-dependent factors, density- independent factors

density-dependent factors

increase as population density increases

density-independent factors

do not vary with population density

Carrying capacity

the maximum population size that a particular environment can sustain

r-selected

species who live in unstable environments. There is a large number of offspring produced, but individuals often die young

k-selected

species who live in stable environments. their population is often at or near carrying capacity

population pyramid

a bar graph that measures age and sex data

survivorship curves

number of individuals still alive at each age

Survivorship Curve- Type 1

low death rate- most live until old age

Survivorship Curve- Type 2

moderate death rate- all ages die

Survivorship Curve- Type 3

high death rate- most die young

competition

a relationship between organisms that strive for the same resources in the same environment

intraspecific competition

two members of the same species fight for a resource

interspecific competition

members of different species fight for a resource

Symbiosis

A close relationship between two species in which at least one specifies benefits

symbiosis- mutualism

both species benefit

symbiosis- commensalism

one benefits, the other is unaffected

symbiosis- parasitism

one species benefits, the other species is harmed