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
how does temperature affect the rate of decomposition
chemical reactions generally work faster in warmer conditions but if it is too hot the enzymes can denature and stop decomposition
how does water affect the rate of decomposition
microorganisms grow faster in conditions with water as it is needed for respiration. water also makes food easier to digest
how does availability of oxygen affect decomposition
most decomposers respire aerobically
what is compost
decayed biological material
what is compost used for
natural fertiliser for farmers and gardeners
what is methane gas made from
microorganism that decompose waste anaerobically
what is methane used as
burnt as a fuel
what are biogas generators used for
to produce methane
requirements for biogas generators
require a constant temp of 30 so the microorganisms keep respiring
it cannot be stored as a liquid so needs to be used immediately
examples of environmental changes
temperature
water availability
atmospheric gas composition
what do environmental changes effect
the distribution of species in an ecosystem
how does temperature impact species in ecosystems
climate change may lead to insects migrating to places in the world which are becoming hotter
how does water availability affect species in an ecosystem
populations will migrate to find water
how does atmospheric gas composition affect species distribution
certain pollutants which affect distribution of organisms eg lichen cannot grow in places where sulfiur dioxide is present
what can environmental changes be
seasonal
geographic
caused by human interaction
what is biodiversity
the variety of different species of organisms on earth or within an ecosystem
what does high biodiversity mean
the ecosystem will be stable
what does biodiversity result in
species being less dependent on each other for things such as food and shelter
what does the future of humans on earth depend on
maintaining biodiversity for food and medicines
why is the impact of human activities getting bigger
the population is increasing
so more resources are being used
meaning more waste is produced
which ways are humans destroying biodiversity
more land used for commercial and residential property which destroys habitats
pollution kills plants and animals
we are using up raw materials quicker than they are being produced
which chemicals pollute the water
sewage
fertiliser
toxic chemicals
what pollutes the air
smoke
acidic gases
what pollutes the land
landfill
toxic chemicals
what is the result of humans taking up land
reduces the number of habitats for animals and plants by building, quarrying , farming and dumping waste
what is peat
a material that forms when plant material has not fully decayed as there is not enough oxygen
where does peat accumulate
bogs that are acidic and waterlogged
what is the use of bogs that peat grows in
habitat for many species , in particular migrating birds
what is being done to peat bogs
they are being destroyed - drained to create space for farming
peat is used as compost
peat is dried to use as fuel as it contains carbon
why is peat being used up quicker than it is being formed
the formation process is slow
what is deforestation
the cutting down of a large number of trees in the same area to use the land for something else
why does deforestation happen in tropical areas
to provide land for cattle and rice fields
to grow crops eg sugarcane for biofuels which are used to produce energy
what are the problems caused by deforestation
as trees contain carbon , burning them results in co2 release contributing to global warming
trees take in co2 in photosynthesis so less is taken in
number of habitats are reduced decreasing biodiversity
what happens after deforestation that causes problems
microorganisms decompose the dead vegetation producing co2 as they respire
what is global warming
the temperature around the world increasing because we are producing more greenhouse gases
what does increased greenhouse gas production result in
more heat is absorbed and reflected back to earth , heating it up
what are the consequences of the global temperature increase
melting ice caps reducing habitats
rising sea levels reducing habitats as low lying areas are flooded with salty water
temperature and rainfall levels will affect migration and the distribution of different species as they may no longer survive
organisms become extinct as their habitats are lost reducing biodiversity
examples of positive human interactions with ecosystems
maintaining rainforests ensuring habitats are not destroyed
reducing water pollution and monitoring the changes over time
preserving areas of scientific interest by stopping humans going there
replanting hedgerows and woodlands to provide previously destroyed habitats
examples of negative human interactions with ecosystems
production of greenhouse gases leading to global warming
producing sulfur dioxide in factories which leads to acid rain affecting habitats
chemicals used in farming leak into the environment
clearing land in order to build on, reducing the number of habitats
what has been done to reduce our negative impact on ecosystems
programs have been put in place to maintain biodiversity
examples of programs put in place to maintain biodiversity
breeding programs to stop endangered species becoming extinct
protection of rare habitats to stop species here becoming extinct, if damaged they can be regenerated to encourage populations to live here
reintroduction of hedgerows and field margins where only one type of crop is grown
reduction of deforestation and carbon dioxide production reduces rate of global warming slowing down the rate of habitats destroyed
recycling rather than dumping waste in landfill reduces amount for land taken up for landfills
what are trophic levels
different stages in the food chain represented by numbers
what is level 1
organisms at the first level are called producers such as plants and algae
make their own food by photosynthesis
what is level 2
primary consumers
herbivores that only eat plants
what is level 3
secondary consumers
carnivores that eat herbivores
what is level 4
tertiary consumers
carnivores that eat other carnivores
no predators, top of food chain - called apex predators
what do decomposers do
break down dead plant and animal matter
how do decomposers work
secrete enzymes
so the matter is broken down into small soluble food molecules
so they move into the microorganism by diffusion
what do pyramids of biomass show
the relative biomass at each trophic level
how are pyramids of biomass organised
shows relative weights of material at each level
there is less biomass as you move up the trophic levels
biomass of the organism in the level above will always be higher
how much incident energy from light do producers transfer
1% because not all light lands on the green parts of the plant
how much biomass of each trophic level is transferred to the next
10%
why is a small amount of biomass of each trophic level transferred to the next
not all biomass can be eaten
not all of the biomass eaten is converted into biomass of the animal eating it
examples of how not all biomass can be eaten
carnivores cannot generally eat bone, hooves , claws and teeth
examples of how not all of the biomass eaten is converted into biomass of the animal eating it
lots of glucose is used in respiration which produces co2 as waste
urea is a waste substance released in urine
biomass consumed can be lost in faeces
herbivores do not have all the enzymes to digest the material they eat so it is egested
efficiency of biomass transfers equation
biomass transferred to the next level/ biomass available at the previous level x100
why is it common to find less animals in higher trophic levels
because less biomas is transferred each time
what is food security
having sufficient food to feed the population
which factors affect food security
increasing birth rate
changing diets in developed countries
new pests and pathogens can destroy crops
climate change affects food production
conflicts in some countries
how does changing diets affect food security
food resources which are already in low amounts become even more scarce as the demand for them increases
how do new pests and pathogens affect food security
they can destroy crops
how does an increasing birth rate affect food security
more food is required
how does climate change affect food secutirty
it affects food production eg no rain resulting in crops failing
how does conflict in countries affect food security
it can affect the availability of water and food
what is needed to feed everyone on earth
sustainable methods
how do farmers improve efficiency
increase the amount of energy from food converted to biomass in livestock
how do farmers increase energy converted to biomass
reduce the energy transfer from animals to the environment by
raising them in small cages so there is less movement so less energy wasted
areas where they are kept have high temperatures so less energy is wasted on controlling body temperature
why does the efficient farming have ethical objections
lots of animals are kept in a small place causing distress
increased risk of infection spreading
standard of living low for animals
why is the number of fish decreasing
humans are fishing at a faster rate than the populations can regenerate
how can we avoid fish species disappearing in some areas
the populations need to stay above a certain level so breeding can continue
what restrictions have been put in place to keep fish population stable
limits of net sizes making them bigger so smaller fish are not caught and can reach breeding age to produce more fish
fishing quotas mean only a certain number of species of fish can be caught in an area over a time period to prevent overfishing
what is biotechology used for
to help feed the population and potentially provide treatments for a number of diseases
which fungus can produce mycoprotein
fusarium
properties of mycoprotein
protein rich food source
suitable for vegetarians
grown on glucose syrup in aerobic conditions
fungus is harvested and purified so it can be consumed
protein without animals
what is the benefit of producing protein without animals
reduced land use as a lot of land is needed to rear animals and areas to grow crops to feed them
reduced methane contribution from cows
how can insulin be produced
genetically modified bacteria
process of genetically modified bacteria producing insulin
insulin taken and purified
used to treat people with diabetes
what are the advantages of genetically modifying crops
modifying them to be resistant to pests or extreme weather conditions can increase yields
modifying them to increase their nutritional value is beneficial where they lack access to certain vitamins such as golden rice
