7.1 Adaptations, interdependence and competition

define habitat

the place where an organism lives

define population

a group of organisms of the same species living in a habitat

define community

group of interdependent living organisms in an ecosystem

define ecosystem

the community of organisms interacting with the non-living and living factors of their environment

define interdependence

the network of relationships between different organisms within a community

what does an ecosystem include?

-the habitat

-the populations of plants and animals that live in the habitat

-the climate and other environmental conditions

-other conditions in the habitat e.g soil type

-how all of these things interact

how can animals and plants interact in an ecosystem?

-plants produce food by photosynthesis

-animals eat plants

-animals pollinate plants

-animals eat other animals

-animals use plant and animal materials to build nests and shelters

-plants need the nutrients from animal droppings and decay

what is meant by stable community?

communities where the environmental factors are relatively constant

species of living organisms in balance

if the environmental factors change it is in regular patterns

examples of stable communities

-tropical rainforests

-oak woodlands

-mature coral reefs

why are stable communities important?

-take a long time to evolve and cannot be easily replaced

-include high range of biodiversity

define biotic factors

factors caused by living organisms

define abiotic factors

non living factors

examples of biotic factors

-amount of predator/prey

-food availability

-diseases

-competition for resources

-hunting by humans

examples of abiotic factors

-soil mineral content + pH

-light intensity

-rainfall

-temperature

-oxygen levels

-carbon dioxide levels

how and why does food availability affect organisms?

when there is plenty of food, organisms breed successfully

when food is in short supply, animals struggle to survive and often don’t breed

how and why do pathogens and disease affect organisms?

when a new pathogen or parasite emerges, organisms have no resistance to the disease, a new pathogen can damage and even wipe out populations in a community

how and why do predators affect organisms?

organisms that have no defences against new predators may quickly be wiped out

how and why do interspecific competition affect organisms?

new species may outcompete another to the point where numbers become too low for successful breeding

how and why does temperature affect plants?

Temperature = limiting factor for photosynthesis

warmer temperatures mean plants photosynthesise faster so grow bigger and faster

how and why does temperature affect animals?

if more plants grow - more food for animals, so animals population increase

how and why does soil pH affect plants?

affects rate of decay and controls the release of mineral ions back into the soil

acidic pH inhibits decay and therefore reduces the number of plant species that can grow

how and why does soil pH affect animals?

if more plants grow - more food for animals, so animals population increase

how and why does soil minerals affect plants?

-If more nitrate ions - increased plant growth as can make more amino acids for proteins

-If more magnesium ions - increased plant growth as more chlorophyll for photosynthesis

-If low mineral content - then fewer plants, although some have adapted to growing in poor mineral areas by trapping and digesting animals

how and why does soil minerals affect animals?

if more plants grow - more food for animals, so animals population increase

how and why does light intensity affect plants?

limiting factor for photosynthesis

increased light intensity - plants photosynthesis faster to grow faster

how and why does light intensity affect animals?

if more plants grow - more food for animals, so animals population increase

how and why does availability of water affect plants?

if not enough water - no plants grow

if correct level - plants grow better

how and why does availability of water affect animals?

if no water animals will die

if correct level - more food as more plants

how and why does availability of oxygen affect plants?

oxygen levels not usually limiting but if more animals - more predation by herbivores

how and why does availability of oxygen affect animals?

in most cases, if higher oxygen levels, more animals can grow

more food as more plants

how and why does availability of carbon dioxide affect plants?

limiting factor for photosynthesis

increased carbon dioxide levels - plants photosynthesis faster so grow faster and bigger

how and why does availability of carbon dioxide affect animals?

some blood-sucking insects are attracted to carbon dioxide

more food as more plants

how can rainfall be measured?

-Rain gauge

-measured in mm

-measured daily at the same time

-rain gauge consists of a funnel that empties into bottles, the daily contents of the bottles poured into a measuring cylinder

how can temperature be measured?

-measured by thermometer in degrees Celsius

Maximum-minimum thermometers:

-each side contains pin which moves inside with the liquid: one pin records maximum and the other records minimum temp. after readings taken, pins reset using magnet

-measured when temp is needed, daily at the same time

Digital thermometer:

-connected to a data logger, no one needs to be there to take readings

-measured almost continuously

how can oxygen levels be measured?

-digital oxygen probe

-measured in percentage or parts per million (ppm)

-measured almost continuously

-measured by being connected to a data logger

define competition

an interaction between organisms or species in which both require a resource that is in limited supply

what can plants compete for?

light

space

mineral ions

water

what can animals compete for?

food

water

mates

shelter

territory

define predator

organism that hunts, kills and eats other organisms

define prey

the organism that is hunted, killed and eaten by predators

define adaptation

a body part, feature or behaviour that helps a living organism to become more suited to its environment and therefore increases chance of survival

these adaptations can be structural, behavioural or functional

what are behavioural adaptations?

the behaviours of an organism (e.g how they act) that help them survive in their environment

what are functional adaptations?

the processes that take place within an organism that help them survive in their environment

examples of structural adaptations

-colour of an organism

-shape of an organism

-protective body

examples of behavioural adaptations

-a squirrel running away from the sound or sight of a dog to avoid harm

-a lizard sitting on a hot rock to warm up

-a spider spinning a web to catch flies

examples of functional adaptations

-the ability of camels’ kidneys to produce concentrated urine to help conserve water

-a venomous snake’s ability to produce venom

-the ability of the wood frog to produce antifreeze chemicals so that its cells don’t freeze during winter

define extremophile

an organism that can survive and reproduce in very extreme conditions

what types of organisms are often extremophiles?

bacteria and archaea

define surface area to volume ratio

how many times bigger or smaller the surface area is compared to the volume

can be expressed as ratio or decimal

how does SA:V relate to bio?

-the bigger the total volume, the smaller the surface area to volume ratio

-shapes with smaller surface area to volume ratio will retain their heat longer

-shapes with a large volume can increase their heat loss by increasing the surface area