b16 - adaptations, interdependence and competition

anki exported for the eoy cram

species definition

organisms with similar characteristics that can reproduce to produce fertile offspring

population definition

the number of individuals of one particular species in an ecosystem

community definition

all of the living organisms of different species in a space at a given time

ecosystem definition

the community and abiotic factors

abiotic factors in an environment

• oxygen availability
  - soil pH
  - light intensity

general food chain pattern

producer -> primary consumer -> secondary consumer -> tertiary consumer

what is competition

the sruggle between organisms for limited resources

what do animals compete for

• food
  - mates
  - territory

what do plants compete for

• light 
  - space
  - water
  - mineral ions

competition types

interspecific and intraspecific

interspecific competition

competition between different species

intraspecific compeititon

competition between the same species

two ways of sampling biotic factors

transects and quadrats

how are arctic animals adapted to their surroundings?

they are round with short legs

how are desert animals adapted

large ear and long legs

plant adaptations to stop herbivores

• touch me nots
  - mimicry
  - thorns
  - sticky

what are extremophiles

organisms that have adaptations that enable to live in environments with extreme conditions of salt, temperature or pressure

what are adaptations categorised into

structural, behavioural or functional

how to stop heat transfer with SA:V ratio

low SA:V ratio

abiotic factors

• light intensity
  - temperature
  - moisture levels
  - soil pH
  - mineral content of soil
  - wind intensity
  - wind direction
  - availability of oxygen for aquatic animals
  - carbon dioxide levels

biotic factors

 - availability of food
- new predators arriving
- new pathogens
- new competitors

what categories of adaptations are there

• structural
  - behavioural
  - functional

what is interdependence?

the dependence of organisms on each other for resources such as food, shelter, pollination and seed dispersal

what is a stable community?

a community in which all the species and environmental factors are in balance so that population sizes remain fairly constant

why are stable communities important?

they maintain biodiversity and allow ecosystems to function properly

give an example of interdependence between species.

bees pollinate flowering plants and obtain nectar from them

what may happen if one species in a food web decreases?

the populations of other species in the food web may also change

what may happen if a new predator is introduced into an ecosystem?

the populations of its prey may decrease and the whole community may be affected

what is distribution?

where organisms are found within an area

what is abundance?

the number of organisms of a particular species in an area

why do ecologists study distribution and abundance?

to investigate how organisms interact with each other and with their environment

what is a quadrat?

a square frame used to sample organisms in a habitat

when are quadrats used?

to estimate the abundance of plants or slow-moving organisms

what is a transect?

a line along which samples are taken to investigate changes in distribution

why are random samples taken?

to avoid bias

what does competition occur because of?

resources being in limited supply

why is competition usually greater between members of the same species?

because they require exactly the same resources

what is an adaptation?

a feature that enables an organism to survive in its environment

what is a structural adaptation?

a physical feature that helps an organism survive

what is a behavioural adaptation?

the way an organism acts to survive

what is a functional adaptation?

an internal process that helps an organism survive

why do arctic animals have a small surface area to volume ratio?

to reduce heat loss

why do arctic animals have thick layers of fat or fur?

to provide insulation and reduce heat loss

why are many arctic animals white?

for camouflage in snow and ice

why do desert animals have a large surface area to volume ratio?

to increase heat loss

why do desert animals have large ears?

to increase the surface area for heat loss

how do desert animals conserve water?

they produce very concentrated urine and little sweat

why do many desert plants have reduced leaves or spines?

to reduce water loss by transpiration

why do many desert plants have a waxy cuticle?

to reduce evaporation of water

why do many desert plants have extensive root systems?

to absorb as much water as possible

why do some desert plants have fleshy stems?

to store water

why do woodland plants often have large leaves?

to absorb as much light as possible in shady conditions

what is mimicry?

when one organism resembles another organism or object to avoid being eaten

give an example of a plant adaptation against herbivores.

thorns or poisonous chemicals

where are extremophiles found?

in environments such as hot springs deep-sea vents and salt lakes

why are extremophiles important to scientists?

their enzymes can be used in industrial processes

what is biodiversity?

the variety of different species living in an ecosystem

how can a change in abiotic factors affect organisms?

it can change their distribution and abundance

how can a change in biotic factors affect organisms?

it can change population sizes and alter the stability of communities