Ecology (Paper 2) Flashcards
Community meaning
Populations of all different species that live in same habitat
Interdependence meaning
Species depends on another species in a community for survival
Habitat meaning
Place (environment) where an organism lives
Population meaning
Total number of organisms of same species living in same geographical area
Niche meaning
Role of an organism in an ecosystem
Stable community meaning
All species and environmental factors are in balance so that population size remain fairly constant
Distribution meaning
Where an organism is found in its environment
Abundance meaning
Measure of how common/ rare a species is in a particular environment
2 types of competition
Intraspecific (same species)
Interspecific (different species)
3 types of adaptation
Behavioural
Structural
Functional
Behavioural vs structural vs functional adaptation
Structural= physical features e.g Sharp claws
Behavioural= certain behaviours e.g hunting in packs
Functional = processes e.g snakes producing venom
3 conditions needed for decay
Temperature (warm)
Oxygen
Moisture
2 main air pollutants
Noxious gases
Particulates
Eutrophication is the effect of what on water
Fertilisers and sewage
Explain process of eutrophication (effect of sewage and fertiliser on water)
Fertiliser/ sewage ends up in water
Algae grow rapidly to form layer on top of water (algal bloom)
Sunlight blocked so plants die as they can’t respire
Bacteria decompose plants and use up oxygen in water making it anoxic
Aerobic animals like fish can’t respire so die
Ecosystem meaning
Interaction of community of living organisms with the abiotic factors of their environment
Factors that effect distribution of plants
Light intensity
Soil ph
Minerals
Space
Competition
Water
O2 availability
Intraspecific vs Interspecific competition
Inter= between different species
Intra= between same species
What are extremophiles
Animals adapted to live in extreme environments e.g extreme temperature, ph, pressure and salt concentration
What are tropic levels
Different levels within a food chain
Is the producer or apex predator trophic level 1
Producer= trophic level 1
Why are producers called producers
Able to use photosynthesis to produce their own food using energy from the sun
Why do most food chains consist of no more than trophic levels
As you go up the food chain more energy is lost so there isn’t enough energy to sustain the organisms at the higher trophic levels (only 10% energy is passed on each time)
2 key examples of de composers
Bacteria
Fungi
1 key example of detritivores
Worms
What arrows in food chain show
Transfer of energy and biomass
Decomposer meaning
Organism that breaks down dead organisms
Detritivore meaning
Organisms that feed on the remains of dead plants and animals
Decomposer vs detritivore
Decomposer breaks down dead organic matter
Detritivore then feeds on this dead organic matter (dead plants and animals)
What do pyramids of biomass show
Biomass of each trophic stage in a food chain
Why not all biomass passed onto the next stage of the food chain (only around 10% is passed on)
Not all part of organism is eaten e.g carcass of animal
Not all material is absorbed so gets egested as faeces
Most nutrients absorbed are used to produce energy from respiration so biomass is released as waste products like urea and carbon dioxide
What % of biomass is passed from one trophic level to the next
10%
5 examples of condition of area where extremophiles live
Very high/ low temperature
Very high/ low ph
High salt
High pressure
Low level of oxygen
Decomposition meaning
Break down of dead organic matter
(Into water/ minerals/ CO2…)
Examples of what dead organic matter is broken down into when decomposed
CO2, minerals, water
True or false, decay and decomposition are the same thing
True
True or false, the whole decomposition process is carried out by both de composers and detritivores
True
It includes both the breaking down of dead, organic matter and then detritivores feeding on it
Why oxygen is needed for decomposition
De composers e.g bacteria and fungi need it to aerobically respire. More oxygen means increased rate of respiration means more energy released means de composers can work faster in breaking down the dead organic matter
Why moisture is needed for decay/ decomposition
De composers need water to survive (and therefore moisture)
Moisture is needed for decomposition because de composers need …. to survive
Water
Why does a higher temperature increase rate of decomposition
Particles have more kinetic energy so move faster and rate of reaction is higher
Enzymes closer to optimum temperature so break down dead organic matter at faster rate
So increases rate of decomposition
High temperatures increase rate of decomposition but what happens if they’re too high
Enzymes denature
Rate of reaction decreases
So Rate of decomposition decreases
Moisture is needed for a higher rate of decomposition but why can’t it be too moist (too much water) e.g waterlogged soils
Oxygen levels drop (as water fills the air gaps in the soil)
Rate of decomposition decreases as rate of respiration lower so less energy produced for de composers to break down the dead organic matter
What is compost
A mixture of broken down (decomposed) dead organic material used to fertilise and improve the soil
What is compost made from
A mixture of broken down (decomposed) dead organic material
When does anaerobic decay occur
When decomposers anaerobically respire
What does anaerobic decay produce
Biogas containing methane
What can the methane from anaerobic decay be used for
Fuel as when burnt it releases lots of energy
How does biogas generator work in decay
Dead/ organic matter put in tank left to decay anaerobically
Process produces methane
Methane removed (used as fuel)
Sludgy material left behind which can be used as a fertiliser as it contains high density of useful minerals
Stages of water cycle
1) energy from sun causes some water to evaporate (e.g from lakes/ oceans/ rivers/ puddles /soil and leaves of plant (transpiration))
(Water on earth’s surface evaporated into water vapour forming warm, moist rising air)
2) water vapour rises, cools then condenses to form clouds
3) precipitation
Water droplets in clouds fall as rain/ snow/ hail
4) Percolation/surface run off
Some water trickles through gaps in soil and rocks, some taken in by plants (photosynthesis) some goes back into ocean/river etc
In the first stage of the water cycle what sources is the water in on the earth’s surface
Lakes/ rivers/ oceans/ puddles/ soil/ plants and animals
(Forms water through evaporation/ transpiration in plants/ respiration in plants and animals)
3 ways water on earth’s surface ends up as water vapour
Evaporation (river/ puddle/ oceans etc)
Respiration (in plants and animals)
Transpiration (in plants)
In the water cycle what makes the water vapour form clouds
First warm moist air rises
As it reaches higher up it cools and condenses to form clouds
5 stores of carbon in carbon cycle
Air (carbon dioxide)
Plants
Animals
Soil (in the microorganisms like bacteria)
Fossil fuels
3 Processes that lead to carbon being transferred from/ to plants in carbon cycle
Photosynthesis- plants take in CO2 from air
Respiration- CO2 released back into air
Organism feed on plants- carbon passed on to these animals
What 2 things can happen to carbon in carbon cycle when plants/ animals die
Dead organic plant/ animal matter is decayed (decomposed)
During decomposition microorganisms like bacteria aerobically respire so release CO2 in aerobic respiration
Anaerobic conditions- dead organic matter converted into methane (fossil fuel) which can be burnt to release CO2 (burning dead plants like logs on a fire also releases CO2)
What is biodiversity
The variety of all different species of organisms on Earth/ in an ecosystem
Biodiversity makes ecosystems what
Stable
Why does biodiversity make ecosystems stable
If there are lots of different species in an ecosystem, if one goes extinct the other organisms will still be able to survive as they can rely on other species for food etc
2 reasons why biodiversity is important for humans
For medical drugs (medicine) and pollinating crops (provides food)
Increased population means what 2 things that are reducing biodiversity
More resources being used (e.g deforestation to build new homes)
More waste produced (e.g toxic chemicals which can pollute the river and kill fish)
5 key ways to maintain biodiversity
Breeding programmes
Recycling resources
Protection and regeneration of rare habitats
Reintroduction of hedgerows
Reducing deforestation and carbon emissions
How breeding programmes help maintain biodiversity
Set up for endangered species in zoo to reduce chance of them becoming extinct
E.g pandas bred in zoos where it’s safe to increase their numbers before they can be gradually released into the wild
Not always effective if the endangered species doesn’t have a safe habitat in the wild to go back into or else their numbers will just decline again
How protection and regeneration of rare habitats helps maintain biodiversity
Ensures habitat for endangered animals is safe to help reduce chance of them going extinct (often endangered species will be let back out into their natural habitat after breeding programme in zoo)
How reintroduction of hedgerows and field margins (green space where plants can grow) helps maintain biodiversity
Provides habitat so wide variety of organisms like plants/ birds etc can live there and more species can survive
How reducing deforestation and CO2 emissions helps maintain biodiversity
Government setting quotas (restrictions) on these things
(Less deforestation means less habitats lost, less CO2 means less contribution to global warming so less ice caps melting etc)
How recycling resources helps maintain biodiversity
Reduces how much stuff ends up in landfill which can then kill marine animals if plastic ends up in sea/ means more new resources need to be obtained which involves burning fossil fuels in factories/ mining which takes away habitats etc
3 key sources of land pollution
Sewage (bodily waste/waste water from homes that can pollute soil)
Household waste/ industrial waste (goes into landfill and takes up lots of space destroying habitats and industrial waste can contain harmful chemicals that seep into soil and poison it)
Pesticides in farming- (kill insects and if in soil can be washed into streams and rivers and ingested by fish, killing then/ contaminate plant material that’s then eaten by animals, killing them)
What is eutrophication
The process where sewage and fertiliser has an effect on the water
Nutrients added to water
Causes algal bloom (algae grow rapidly)
Blocks out sunlight for plants
Plants die
No more photosynthesis so no oxygen (water becomes anoxic) as bacteria decompose plants and use up oxygen in water
Animals can’t aerobically respire so die
What is bio accumulation (process that reduces biodiversity)
Toxic chemicals wash into water and enter food chain
Chemicals build up through each stage of food chain (concentration of pesticide builds up as more and more plants/ animals with it in them are eaten)
Top predators unable to breed/ die (e.g in Birds of Prey toxic chemicals can cause the egg shell to break so they can’t successfully produce any offspring)
Biodiversity reduced
What is smog
Mixture of small particles and acidic gases trapped in atmosphere
(Distinctive brownish haze)
What 2 health problems can smog cause (trapped acidic gases and small particles in atmosphere)
Eye and lung irritation
What 2 things is smog made up of that get trapped in atmosphere
Small particles
Acidic gases
3 Problems with smoke
Global dimming (more particulates in air to reflect sunlight, less light hits earth’s surface)
Lung damage
Reduced photosynthesis
What are peat bogs
Areas of partially decayed vegetation
Why do humans destroy peat bogs
To be used for garden compost
2 reasons destruction of peat bogs (areas of partially decayed vegetation) is bad
Reduces habitat for different organisms
When peat is burnt for energy it releases CO2
Why is only 1% of energy from sunlight used for photosynthesis
Most light doesn’t hit plant
Some light reflected off waxy cuticle
Not all wavelengths of light absorbed (green reflected)
Some light passes straight through leaf without hitting chloroplast
What is food security
Having enough food to feed the population (everyone can access the food they need)
6 factors affecting food security
Conflict- trade routes disrupted so can’t export/ import food
Droughts
Pests/ pathogens
Increasing population
Changing diets (scarce food resources transported to developed countries)
GM crops (increases food production but is expensive)
2 sustainable fishing methods
Fishing quotas- especially on species with reduced numbers
Net size- big holes to stop smaller/ younger fish being caught
Its important to maintain fish stocks where what can continue
Breeding
5 advantages of mycoprotein (meat alternative)
High fibre
Low fat
High protein
Suitable for vegetarians
Cheap
Population is the total number of….living in the same…
organisms of the same species
Geographical area
Population is the total number of….living in the same…
organisms of the same species
Geographical area
Population is the total number of organisms of the same… living in the same geographical area
Species
Community is the populations of all different…that live in the same…
Species
Habitat
Community is the…of all different species that live in the same habitat
Populations
Examples of Abiotic factors
Light intensity
Carbon dioxide levels (for plants)
Water levels in soil
Mineral content in soil
Soil PH
Wind intensity and direction
Temperature
An ecosystem is the…. of a community of living organisms with the….of their environment
Interaction
Abiotic factors
Interdependence means that species depend on… for survival
Another species in a community
4 key things Plants compete for
Light
Space
Water
Mineral ions in soil
4 key things Animals compete for
Food
Water
Mates
Territory
A stable community is one where all the..and….factors are in….so that population size remains…
Species
Environmental
Balance
Fairly constant
Biotic factors are living factors in the….that can effect the…
Ecosystem
Community
Abiotic factors are non living factors in the ….that can affect the..
Ecosystem
Community
4 biotic factors that would negatively affect the populations in a community
Decreased availability of food
New predators arriving
New pathogens
Competition between species
4 biotic factors that would negatively affect the populations in a community are decreased availability of…., new…arriving, new….and competition between….
Food
Predators
Pathogens
Species
4 biotic factors that would negatively affect the populations in a community are decreased availability of…., new…arriving, new….and competition between….
Food
Predators
Pathogens
Species
What are extremophiles
Organisms which live in extreme environments e.g highly acidic/ alkali, low levels of oxygen or water, very high or low temperatures, extreme pressures, high salt conditions
Extremophiles are organisms which live in very extreme environments
Give 5 examples of these extreme environments
Very high or low temperature
Low water or oxygen levels
High salt concentration
Extremely acidic or alkali
Extreme pressures
1 key examples of extremophiles are bacteria which live in…
Deep sea vents
Decomposition is the break down of dead…
Organic matter
3 key sources of land pollution are…
Sewage
Industrial/ household waste
Pesticides
3 key sources of land pollution are…
Sewage
Industrial/ household waste
Pesticides
Smog is a mixture of small… and acidic…trapped in the
Particles
Gases
Atmosphere
Smog is a mixture of small… and acidic…trapped in the
Particles
Gases
Atmosphere
