biology (test)

define organism

an individual living thing that carries on the activity of life

define population

group of individuals of the same species that live in the same area and can reproduce with one another.

define species

group of organisms that can naturally mate with one another and produce fertile offspring.

define community

all the different populations of different species living and interacting in the same area.

define ecosystem

community of living organisms together with the nonliving parts of their environment interacting as a system.

define biome

a distinct geographical region that is characterised by specific environment conditions

define biosphere

the part of earth where life exists. It includes all living organisms and all the ecosystems on earth

define symbiotic relationship

the interatons between two or more specific that may or may not beneficial to each other

define commensalism

interaction between species in which only one species benefits. but the other is not harmed

define amensalism

interaction between two organsims of different species where one organism experiences harm while is other experiences neither a benefit or negative effect

define mutualism

two organisms that live closely together and both benefit, but organisms depend on eachother for survival

define parasitism

one species (parasite) benefits and the other species (host) is harness parasute obtains its food from the host but does not kill it

define competition

both organisms trying to obtain the same resource, that may be scarce, this could be between different species or of the same

define food chain

the series of organisms linked by their feeding relationships

define food web

a series of interacting food chains that link up

define autotroph

organisms that manufacture their own food via photosynthesis

define heterotrophs

organisms that obtain their energy by consuming other organisms

define keystone species

a keystone species is a species whose effects on the ecosystem are greater than expected relative to its population size

define tropic levels

the location of where an organism sits on the food chain

define ecological diversity

variations within an environment where organisms live

define species divisity

variations of species in a ecosystem

define genetic diversity

variations between individuals of a species

what are the types of adaptions

structural, physiological, behavioural

define structural

body structure that allows an animal to find and consume food, defend itself and to reproduce its species

define physiological

occur within the body organ tissue of an animal or plant. they are sometimes hard to see

define behavioural

actions or patterns of activity that organisms develop to survive and reproduce in their environment.

define biotic factors

all living organisms in an ecosystem

define abiotic factors

non-living physical and chemical components in an ecosystem

define natural selection

the process where better adapted organisms survive and reproduce

how can genetic variations can be affected by

chance events, selective breeding, isolating population

what does VISTA mean

variance, inheritance, selection pressures, time, adaptation

define evolution

this survival and spread of beneficial traits with entire populaton over time

define selecton pressures

external factors which affects on organisms ability to survive in an environment

examples of selection pressures

resource availability, environment condition, biological factors, sexual selections