Ecology Flashcards
what is a community
many different populations interacting in the same habitat
what is an ecosystem
the interaction of a community of living organisms (biotic) with the non living (abiotic) parts of the environment
what do organisms require to survive and reproduce
a supply of materials from their surroundings and from other living organisms there
what is interdependence
organisms in a community depend on other organisms for vital services
what do plants compete for
light
space
water
mineral ions
what do animals compete for
space
food
water
mating partners
examples of needs from interdependence
food
shelter - birds take shelter in trees
reproduction (pollination) - flowers pollinated with help of bees
what is the result of adding or removing a species from a community
affects the population of others as it changes prey or predator numbers
what is a stable community
a community where all the species and environmental factors are in balance so the population sizes remain fairly constant
what is an abiotic factor
a non living factor
which abiotic factors can affect a community
light intensity
temperature
moisture levels
soil ph and mineral content
wind intensity and direction
carbon dioxide levels
oxygen levels for aquatic animals
how does light intensity affect a community
light is required for photosynthesis
the rate of photosynthesis affects the rate the plant grows
plants can be food sources or shelter for many organisms
how does temperature affect a community
temperature affects the rate of photosynthesis
how do moisture levels affect a community
both plants and animals need water to survive
how does soil ph and mineral content affect communities
soil ph affects the rate of decay therefore how fast mineral ions return to the soil (which are then taken up by other plants)
different species of plants thrive in different nutrient concnetration levels
how does wind intensity and direction affect communities
wind affects the rate of transpiration in plants
transpiration affects the temperature of the plant and the rate of photosynthesis because it transports water and mineral ones to the leaves
how do oxygen levels affect communities of aquatic animals
levels in water vary greatly unlike oxygen levels in air
most fish need a high concentration of oxygen to survive
what is a biotic factor
a living factor
which biotic factors can affect a community
food availability
new predators
new pathogens
competition
how does food availability affect a community
more food means organisms can breed more successfully and therefore the population can increase
how do new pathogens affect a community
when a new pathogens arises the population has no resistance to it so they can be wiped out quickly
how does competition affect a community
if one species is better adapted to the environment than another then it will outcompete it until the numbers of the lesser adapted species are insufficient to breed
what kind of adaptations can organisms have
structural
behavioural
functional
why do organisms have adaptations
to allow them to survive in the conditions where they live
what are structural adaptations
the shape or colour of a part of an organim
examples of structural adaptations
sharp teeth of a carnivore to tear meat apart
camouflage such as tan/brown colour of a lionesses coat to avoid prey spotting her
species in cold envionrments have a thick layer of fat for insulation
what is a behavioural adaptation
the way an organism behaves
examples of behavioural adaptations
individuals play dead to avoid predators
basking in the sun to absorb heat
courting behaviour to attract a mate
what is a functional adaptation
involved in processes such as reproduction or metabolism
examples of functional adaptations
late implantation of embryos
conservation of water through producing little sweat
what are extremophiles
organisms that live in environments with extreme conditions
examples of extreme conditions
high temperatures
high pressures
high salt concentrations
example of an extremophiles
bacteria which live deep in sea vents where the pressure is very high
adaptations for cold climates
smaller surface area to volume area ratio to reduce heat loss
lots of insulation from blubber or fur coat
adaptation for dry climates
adaptations to kidneys to retain lots of water producing very concentrated urine
active in the early morning and evenings when it is cooler
resting in shady areas
larger surface area to volume ratio to reduce heat loss
plant adaptation examples
curled leaves to reduce water loss
extensive root systems to take in as much water as possible
waxy cuticle to stop water evaporating
water storing tissue in stem
how are feeding relationships shown
food chains
process of food chains
begin with a producer
producers are eaten by primary consumers
primary consumers are eaten by secondary consumers
secondary consumers are eaten by tertiary consumers
what are producers
photosynthetic organisms (usually a green plant or algae)
how do producers work in the food chain
through photosynthesis they make glucose
glucose is used to make other biological molecules in the plant which make up the biomass
what happens when producers are eaten by primary consumers
energy is transferred through organisms in an ecosystem when one is eaten by another
what happens when primary consumers are eaten by secondary consumers
the animals eaten are called the prey and the consumers that kill and eat them are predators
what are transects and quadrants used for
to work out the distribution and abundance of species in an ecosystem
how is information from transects and quadrants processed
by calculating the mean, mode and median and drawing a graph
what will a stable community show
population cycles between predators and prey
what is the population cycle of predators and prey
if the population of the prey increases the population of predators will also increase
this results in the number of prey decreasing after some time as more would be consumed by the increased number of predators
what happens when there isn’t enough prey to feed the predators
the population of predators will decrease which will allow the population of prey to increase again
how are materials cycled
through an ecosystem
how does the carbon cycle work
- co2 is removed from the air in photosynthesis by green plants and algae - they use the carbon to make carbohydrates, proteins and fats. they are eaten and the carbon moves up the food chain
- co2 is returned to the air when plants, algae and animals respire. decomposes respire while they return mineral ions to the soil
-co2 is returned to the air when wood ad fossil fuels are burnt as they contain carbon rom photosynthesis
how does the water cycle work
- the suns energy causes water to evaporate from the sea and lakes forming water vapour
-water vapour is also formed as a result of transpiration in plants
-water vapour rises and then condenses to form clouds
-water is returned to the land by precipitation (rain snow or hail) and this runs into lakes to provide water for plants and animals - this then runs into seas and the cycle begins again
which factors effect rate of decomposition
temperature
water
availability of oxygen