Ecosystems and environment Flashcards
what is an ecosystem
An ecosystem is made up of a community interacting with the abiotic elements of their environment
what do ecosystems have (3)
producers,consumers and decomposers
what are producers
Ecosystems always have the following:
Producers = plants - produce their own food using photosynthesis
whata are consumers
Consumers = organisms that eat other living organisms (this could be plants or animals)
what are decomposers
Decomposers = organisms that break down dead organisms and help recycle their materials –> commonly bacteria and fungi
what are biotic components
Biotic components = components to do with living organisms
what are abiotic components
Abiotic components = physical things in the environment
what are biotic componets
Biotic Factors: components to do with living things
what is a habitat
Habitat = place where an organism lives
Population = at one point of time, in one place, all the individuals of a particular species
what are abiotic factors (6)
Abiotic factors:
Light Intensity
Temperature
Moisture levels
Soil pH and mineral levels
Wind intensity and direction
Availability of O2
what are biotic factors (5)
Biotic Factors:
Availability of food
New pathogen + parasites
New predators arriving
Interspecific competition (competition between species)
how does availability of food affect the environment
availability of food - animals may move to a new food source, or die of starvation if there is less food
how does new pathogens/parasites affect the environment
new pathogens can wipe out species. However, species can develop mutations which make them immune to the pathogen/parasites, parasites and pathogens can do the same also
how does new predators affect the environment
new predators can disrupt the food chain and if there are too many predators, a species can die out. Alternatively, organisms with no defence against the new predator can die out. As a consequence, the predators acn die since there is nothing to eat.
how does competition between species affect the environment
competition between species - A new species may outcompete another to the point where numbers are too low for breeding
how does light intensity effect the environment
Light Intensity - light limits photosynthesis so it will affect the distribution of plants and animals
how does light intensity effect the environment
Temperature - limits photosynthesis –> affects plants, so affect herbivores, so it affects carnivores
how does moisture levels effect the environment
Moisture levels - no water means little or no life
how does soil ph and mineral levels effect the environment
Soil pH and mineral levels - plants can die leading to herbivores dying. In low mineral soil, carnivorous plants can survive due to animal protein
how does wind intensity and direction effect the environment
Wind intensity and direction - plants may wilt due to the wind intesnity, maintaining a steep concentration gradient for diffusion of water vapour, so plants have a high rate of transpiration. affects the shape of trees and the whole landscape
how does availability of 02 effect the environment
Availability of O2 - plants and animals may die. O2 levels in the air don’t vary as much, so this is a bigger concern for water-living organisms.
what is quadrat
A quadrat is a square frame that is laid on the ground
why must you make sure when deciding a quadrat size
Although there are different sized quadrats, you must keep the size you use consistent for the species you measure.
why are quadrats used
Quadrats are used to investigate the size of the population of plants, and animals that move very slowly, like snails
to ensure quadrats results are reliable, what must be done (3)
To ensure that the results are reliable, random sampling is used
Random sampling: choosing the area in which to place the quadrat
Choose your sample area, and make coordinates in this sample grid
Use a random number generator/ a random coordinate generator to choose where to place the quadrat
why are other methods of results being reliable wrong in other exam boards (2)
Other boards also mention a method of spinning in a circle with eyes closed and throwing the quadrat however this is WRONG - never mention this as a correct method
Problems with this method:
It is not a random method, as before throwing, you choose where to stand to throw it
2. How far it is thrown, is dependent person to person
what is quantative sampling
Quantitative sampling = finding the mean number of organisms per m^2
how do plants interact for the enviornment
Feeding cycle: the plants, animals and decomposers recycle the same nutrients
Interactions between organisms and the environment:
Plants TO the environment: plants release oxygen to help the animals respire in th environment. They also release water vapour
how does the environment help the plants
Plants FROM the environment:plants feed of the minerals from the ground, and photosynthesise from the sun. Plants also absorb CO2 and water
what do animals do for the environment
Animals TO the environment: release feaces to fertilise the soil and die also to fertilise the soil and feed other animals. Some heat which MAY affect the temperature
what do animals do for the environment
Animals FROM the environment: use materials from the environment to build shelters, and respire - take in oxygen
what do animals compete for
Animals compete for:
1. Food
2. Territory
Nesting sites
3. Mates
what do plants compete for
Plants compete for:
Space to grow - allowing roots to absorb water, and leaves to catch light
Light for photosynthesis
Water for photosynthesis and to keep their tissues turgid and supported
Nutrients (Minerals) from the soil to make necessary chemicals in cells
To attract insects for insect-pollination, or access to wind for wind-pollination
abiotic factors for antarcic (6)
temperature
water availability
temperature of water
rough terrain
avalanches
duration of sunlight
abiotic factors for river (10)
temperature of water
current- Flow rate
terrain of river path
nature of the river bed, hard rock, big rocks, sediment etc
water pollution
salt/freshwater
pH
concentration of minerals/nutrients
concentration of oxygen in the water
Depth of river
Cloudiness of water
what are the levels in a foodchain called
These levels in the food chain (producer, primary/secondary consumer etc) are called Trophic Levels
what are the trophic levels called in a food chain
label a to e : A–>B–>C–>D–>E
A–>B–>C–>D–>E
–> = eaten by
A=Producer
B= Primary Consumer = Herbivores
C= Secondary Consumer = Carnivores
D=Tertiary Consumer
E=Quaternary Consumer
E, at the end of the food chain is called a Top Carnivore
what do food chains show
Food chains show how energy is moving through an ecosystem - the arrows show the direction of energy flow
are food chains 100% correct
Even though energy moves from one living organism to the next, not all of the energy is absorbed
Food chains show one possibility, but in reality, an organism can eat, or be eaten by multiple species
This more complex idea is shown in food webs
what is intraspecific competition
Intraspecific competition: Intra = within a species (specific is the adjective for species) –> this means competition WITHIN a species, so competition between individuals of the SAME species
what is interspecific competition
interspecific competition = Inter = between a species (specific is the adjective for species) –> this means competition BETWEEN species, so competition between individuals of DIFFERENT species
competition = fighting for the same resources
what are ecological pyramids
Ecological pyramids - pyramids that show the amount of organisms at a certain trophic level
what are pyramid numbers
Pyramid of numbers - the actual number of individuals in a trophic level (their mass doesn’t matter)
what is a pyramid of biomass
Pyramid of biomass - MASS matters - combined mass of individuals of a trophic level
Why some biomass is lost between each trophic level: (3)
- Some parts of the organism isn’t eaten
- Some parts of the organism are not digested (so they don’t become a part of the next organism’s biomass because it’s not absorbed, the mass is egested as faeces)
- Some of the mass absorbed is respired back out to release energy
Rules for drawing pyramids of biomass:
The first bar, at the bottom, needs to be the bar for the producer, and you follow the food chain up
Bars need to be touching - no spaces between them
Bars are equally spaced around the midpoint
The length of the bar is matched to the amount of biomass
A flowchart of energy in organisms: (6)
Photosynthesis - fixes energy from sunlight into chemicals like glucose and starch
Living organisms release this energy via respiration, using compounds like glucose
This energy released from respiration is used in: muscle contraction, growth, reproduction, active transport
In growth, when energy is used to form new cells, this energy stays fixed in these cells and compounds - so when the next organism in the food chain eats this one, the energy is passed on
Again in the next organism, there are uses of energy, so the amount of energy is lost from food chains and webs at each trophic level
Decomposition:
Microorganisms play their role in decomposition by breaking down complex organic molecules in dead living organisms, into simpler substances. These micoorganisms then release these into the environment
describe the carbon cycle (8)
INTO ORGANISMS:
1. photosynthesis
INTO GROUND
2, decompostition
3, fossilisatioN
OUT OF GROUND
4. burning of fossil fuels
5. extraction by decompostition
INTO AIR
6. decompostition of animals
7. respiration
OUT OF AIR
8. photosynthesis
what is nitrogen fixation
Nitrogen Fixation - this is when nitrogen from the air is FIXED into ammonia (NH3)
where is nitrogen bacteria found (2)
Nitrogen-fixing bacteria is found freely living in the soil
Nitrogen-fixing bacteria can ALSO be found in root nodules of legumes
how does nitrogen fixating bacteria in the soil work
The nitrogen fixed by the bacteria in the soil is used by the bacteria to form amino acids and proteins. When the bacteria dies, the protein is then decomposed into ammonia, which enters the soil.
how does nitrification by bacteria in nodules work
The nitrogen that is fixed in the root nodules is used by the plant to make amino acids and other organic nitrogen compounds. When the plant dies, the plant decomposes, and returns the nitrogen to the soil as ammonia.
what is mutualism
This example, where the two organisms are benefitting from each other is called mutualism/a symbiotic relationship
how does lightning affect the nitrogen cycle
Lightning - Lightning converts nitrogen into oxides of nitrogen, which dissolve in rainwater, and enter the soil, where they are converted into nitrates by nitrifying bacteria.
what are nitrates used for by humans
Humans make nitrates to be used in fertilisers as nitrates increase the rate of growth.
what is denitrifying bacteria
Denitrifying bacteria = it uses nitrates as an energy source, and converts them into nitrogen gas
DEnitrifying –> REDUCES the amount of nitrogen in the soil
what is feeding and assimilation
Feeding and assimilation - feeding = absorbing the nitrogen from the environment (from food, or the soil, depending on animal or plant), and then ASSIMILATION is making amino acids and other organic nitrogen compounds USING that nitrogen
With feeding and assimilation, nitrogen in organic compounds can then be passed along the food chain
how does decomposition play a role in the nitrogen cycle
Decomposition - bacteria and fungi produce ammonia from the nitrogen in compounds like protein, DNA, vitamins
what do nitrigying bacteria do
Nitrifying bacteria –> nitrification - ammonia is first converted to nitrite and THEN nitrate
Nitrates in the soil are taken up by plants.
draw the nitrogen cycle
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draw a diagram for carbon cycle
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