Ecology Flashcards
Habitat
Environment in which an organism lives
Population
Total No of organisms of the same species living in the same geographical area
Community
Pops of all the diff species that live in the same habitat
Ecosystem
Biotic and abiotic parts of an environment and how they interact
What do plants compete for?
Light, space, water and mineral ions from soil
What do animals compete for?
Food, territory, mates, water
Biotic
Living factors of environment
Interdependence
Species depends on other species in a community for food, shelter, pollination and seed dispersal
Abiotic
Non-living factors
Stable communities
- Tropical rainforests and ancient oak woodlands
- all species and environmental factors are in balance, pop sizes are roughly constant
8 Abiotic Factors + explain
- Wind direction and intensity - strong winds blowing inland from sea cause plants to lose water
- Water - some are adapted to managing low levels
- Light intenisty - if its low, photosynthesis rate slows, animals have not enough food
- Moisture level
- Temperature - changes could cause distribution of species to change, migration, plants could disappear
- CO2 level - photosynthesis rate
- Soil pH and mineral content - cant grow if soil is too acidic/alkaline
- Oxygen level - level of dissolves O falls on hot days, harmful to aquatic organisms
4 biotic factors + explain
- New predators arriving - pop of prey species to fall + existing predators could be outcompeted = extinct
- Competition - outcompeted = extict
- New pathogens
- Availibility of food - if it falls, no of organisms in community will fall
Structural adaptations of camels
- Hump - store of fat (thermal insulator), storing fat in 1 place allowed heat loss from other parts of the body, reduces water loss via sweating
- Thick coat on upper surface of body - insulates top of camel from heat of sun, reduces water loss by sweating
- Leathery mouth - can chew desert plants , good source of water
- LONG Eyelashes - keeps dust out
- Can close their nostrils - keeps dust out
- Wide feet - prevents sinkingin sand
Functional adaptations of camels
- Concentrated urine and dry faeces - reduce water loss
- Tolerate large changes in temp - helps them cope with intense heat of desert
What are structural adaptations?
Features of an organisms body structure - shape and colour
What are behavioural adaptations?
Way organisms behave
What are functional adaptations?
Things that go on inside an organisms body eg reproduction, metabolism
Structural adaptations of Arctic fox
- White fur - camouflaged against snow, helps avoid predators + sneak up on prey
- Thick fur - insulation, prevents heat loss
- Small ears - reduces SA of fox, reduces heat loss
Adaptations of cacti
- V small leaves -reduces water loss
- Some dont have no leaves only spines - protect from animals
- Extensive, shallow roots - allow it to catch us much water as possible after rainfall before evaporation/sinking into ground
- Store water in stem - survive many months without rain
Extromophiles
- Microorganisms are adapted to live in extreme conditions
- High temos, high salt conc, high pressure
Structural adaptations of whales
- Thick layer of blubber (fat)
- Low SA:V ratio to help them retain heat
Behavourial adaptations examples
- Swallows migrate to warmer climate during winter to avoid probs of living in cold conditions
Producer
- Makes own food using energy from Sun
- Usually green plants/algae by photosynthesis
What is some glucose used for?
To make other biological molecules in the plant
These BM are the plant’s biomass - mass of living material
What is biomass in plant?
Energy stored in it
What happesn when organisms eat other organisms in an ecosystem?
Energy is transferred
3 facts about a stable community
- Pop of any species is limited by the amount of food availible
- If pop of prey increases, pop of predators will too
- When predators increase, prey decrease
Why are predator-prey cycles always out of phase with each other?
Because it takes a while for one pop to respond to changes in the other pop
What do environmental changes cause?
Changes the distribution of organisms
What enviromental changes can affect organisms?
- Change in the availibility of water
- Change in temp
- Change in the composition of atmospheric gases
What are environmental changes that affect the ecosystem caused by?
- Temperature
- Availability of water
- composition of atmopsheric gases
- seasonal,georgaphic or human ineraciton
Water cycle process
- Energy from sun causes water to evaporate into water vapour + transpiration from plants
- Warm water vapour is carried upwards, when it gets higher up it condenses to form clouds
- Precipitation onto land, provides water for plants + animals
- Some evaporates on land, som epasses through rocks and froms aquifers or rivers
- Drains into sea, process starts again
How are materials like carbon and oxygen returned to the environment by organisms?
In waste products or when organisms die and decay
Why do materials decay?
They’re broken down by microorganisms
What conditions are needed for decay to go faster?
Warm, moist, aerobic (oxygen rich) environments as they’re more active
What does decay do?
Puts the stuff that plants need to grow like mineral ions back in the soil
Process of the carbon cycle
- CO2 removed from atmosphere by green plants/algae during photosynthesis - Carbon used to make glucose which can be turned into carbs,fats,proteins that make up their bodies
- They respire - some carbon returned to atmosphere as CO2
- When plants are eaten by animals, some carbon becomes part of the fats/proteins in their bodies, carbon moves through the food chain
- Animals respire - carbon returned to atmosphrer as CO2
- When plants/animals die, detritus feeders and microorganisms feed and respire CO2
- Combustion of wood and FF releases CO2
- Carbon constantly being recycled
What is compost?
- Decomposed organic matter
- Used as a natural fertiliser for crops and garedn plants
What is the rate of decay affected by? How?
- Temperature - warmer temp = quicker decomposition due to increase rate in enzymes
- Oxygen availibility - Needs oxygen - compost bin has holes in the walls/ mixing compost regularly
- Water availibility - Decay faster in moist environments because ogranisms involved in decay need water to carry out biological processes
- No of decay organisms - more microorgnaims and detritus feeders, faster decomposition
What is biogas?
- Made up of methane, which can be burned as a fuel
- Diff microorganisms used to produce biogas
- They decay plant and animal waste anerobically - this type of decay produces methane gas
How is biogas made?
Why do generators need to be kept at a constant temp?
- In a simple fermentor called a digestor or generator
- Generators need to be kept at a constant temp to keep the microorganisms away
What can’t biogas be stored as? What does that mean?
- Cant be stored as a liquid (needs too high a pressure)
- Has to be used straight away for heating, cooking, lighting, power turbines
2 types of biogas generator
- Batch generators
- Continuous generators
What are batch generators?
- Makes biogas in smal batches
- Manually loaded up with waste which is left to digest
- By-products cleared away at end of each session
What are continous generators?
- Make biogas all the time
- Waste continously fed in
- Biogas made at a steady rate
- Suited to large-scale biogas projects
What do both continous and batch generators need?
- Inlet for waste material to be put in
- Outlet for digested maerial to be removed through
- Outlet so that biogas can be piped where its needed
Biodiversity
Variety of diff species of organisms on Earth, or within an ecosystem
Why is high biodiversity important?
Makes sure ecosystems are stable because diff species depend on each other for shelter/food.
Diff species also help maintain the right physical environment for each other
What is reducing biodiversity?
- Global warming
- Deforestation
- Waste production
Why is the pop of the world increasing v quickly?
- Modern medicine
- Farming methods
- Both reduces number of ppl dying from disease and hunger
Effects on environment due to increasing pop
- Pressure of environment - take resources to survive
- Raw materials cuz ppl demand a higher standard of living (luxury), more energy for manufacuring processes
- Raw materials might run out - more raw material taken than being replaced
How does waste in the water affect the environment?
- Sewage and toxic chemicals from industry pollute lankes, rivers, oceans, bad for plants and animals relying on them
- Chemicals used on land can be washed into water
How does waste on land affect the environment?
- Toxic chemicals for farming
- Bury nuclear waste underground
- We dump household waste in landfill sites
How does waste in the air affect the environment?
- Pollute air - smoke and acidic gases released to atmosphere
- Sulphur dioxide leads to acid rain
What is global warming?
- A type of climate change which can cause other types of climate change
What is increasing the temp of the Earth?
- GG gases absorb most of the energy from the sun that would normally be radiated out into space
What 2 gases in the atmos are rising?
CO2 and methane
Consequences of global warming
- Rising sea levels - ice to melt, seawater to expand, leads to flooding in low-lying reas -> loss of habitat
- Distribution of animals and plants change - due to temp increasing and anount of rainfall in diff areas, some species may become more/less widely distributed
- Changes in migration patterns
- Reduced biodiversity - unable to survive a change = extinct
Crops might not grow
Why is peer review good?
Detects flase claims, makes sure its valid instead of biased, oversimplified or biased
What do humans use land for?
- Building
- Quarrying
- Farming
- Dumping waste
Deforestation, why does it happen?
- Cutting down of forests/trees
- Done to clear land for farming to provide more food
- To grow crops from which biofuels based on ethanol can be produced
Probs of deforestation
- Less CO2 taken in - cutting trees means less CO2 absorbed during photosynthesis
- More CO2 in atmosphere - CO2 released when trees are burnt + microorgniams feed on dead wood and release CO2 as a waste product of respiration
- Less biodiversity - Extinction as forests have huge number of diff species of plant/animals
What are bogs?
- Areas of land that are acidic and waterlogged
- Plants here don’t fully decay cuz there is a lack of oxygen
- Partly-rotted plants gradually build up to form peat
Where does the carbon go in the plants when they die in bogs?
Stored in peat instead of being released to atmos.
What are ppl doing to peat bogs?
- Drained so area can be used as farmland
- Cut up and dried for fuel
- Sold to gardeners as compost
- Being used faster than it forms
What happens when peat is drained?
- Comes into more contact with air
- Some microorganisms start to decompose it
- Microogranisms respire and release CO2 - global warming
What happens when peat is burnt as fuel?
CO2 released
What happens when bogs are destroyed?
- Destroys habitats of animals.plants, microogrnaisms that live there
- Reduces biodiversity
What are peat bogs and lands made of?
Large amount of dead plant materials
What happens to peat when it has been extracted and used for compost?
- Begins to decay
- Release CO2
What would happen if farmers used peat-free compost?
Increase price of food
5 Ways how biodiversity is maintained
- Breeding programmes
- Programmes to protect and regenerated rare habitats
- Programmes to reintroduce hedgerows and field margins
- Gov regulations and programmes to reduce deforestation
- Ppl encouraged to recycle and reudce waste
What are breeding programmes?
- Prevent endangered species from becoming extinct
- Animals bred in captivity to make sure spcies survives if it dies out in the wild
- Sometimes released to wild to boost a pop
What are field margins
- Strip of land around fields where wild plants and animals live
- Cuz farms only have 1 type of crop growing
What are hedgerows?
- Planted between fields
- Species live here
- Preserve biodiversity on farms
4 Conflicting pressures that affect how biodiversity is maintained
- Protecting biodiversity costs money
- Protecting biodiversity may come at a cost to local ppls livelihood
- We have to preotect our food security too
- Development is important, but it can affect the environment
How does protecting biodiversity cost money?
- Gov pay farmers a subsidy to reintroduce hedgegrows and field marginsi ntheir land
- Costs money to keep a watch whether programmed are being followed
- They can be a conflict between protecting biodiveristy and saving money
How does protecting biodiversity affect ppl’s livelihoods?
- Unemployement if deforestation stops
- Affects local economy if ppl move away to find work
Why is there conflict between protecting biodiversity and protecting food security?
- Some organisms like foxes and locusts are seen as pests to farmers so are killed to protect crops so more food can be produced (+ livestock)
- Food chain and biodiversity affected
How does development affect the environment?
- Land is in such high demand that previously untouched land with high biodiversity has been used for development
What are trophic levels?
Diff stages of the food chain, consists 1+ organisms that perform a specific role in the food chain
Trophic Level 1
- Producers - start of chain
- Make own food by photosynthesis using energy from Sun
Trophic Level 2
- Primary consumers
- Herbivores that ONLY eat plants/algae
Trophic Level 3
- Secondary consumers
- Carnivores eat primary consumers
Trophic Level 4
- Tertiary consumers
- Carnivore eats carnivore
Who is at the top of the food chain
- Apex predators - carnivores with no predators
What do decomposers do (bacteria and fungi)
- Decompose any dead plant/animal material
- They do this by secreting enzymes that break the dead stuff down into small soluble food molecules. These diffuse into the organisms
1% of light energy that falls on producers is …
is acc absorbed and used fror photosynthesis
What happens to the biomass and energy every time you move up a trophic level?
- Less energy and biomass
Why does biomass decrease as you move up a trophic level?
- Not all of the material that the organisms ingests is absorbed - some egested as faeces
- Organisms don’t eat every single part of the organism they’re consuming - some are inedible (bone) - not all biomass can be passed to next stage of f. chain
- Some abosrbed material is lost as waste Eg. co2 and water in respiration and water and urea in urine
What is biomass?
Living tissue of an organism inclduing proteins, lipids and carbs
Stores energy
What percentage of biomass from each trophic level is transferred to the level above it?
10%
Formula for efficiency for biomass transfer
biomass transferred to next level/ biomass availbile at previous level X 100
What is food security
Having enough food to feed a pop
Factors that are threatening food security
- World pop increasing, higher birth rates in developing countrie
- Diets in developed countries change, demand for certain foods to be imported from develpoing countries can increase - means scare foods are more scarce
- Farming affected by pathogens and new pests or changes in environmental conditiosn - leads to loss of crops and livestock - widespread famine
- High input costs of farming can make it too expensive for ppl to maintain or start food production - means there aren’t enough ppl to produce food in areas
- Conflicts affect availibility of food
Why is fish stock declining
We are fishing too much
What is sustaiable food produciton
Mainting fish stocks at a level where they continue to breed
2 ways to maintain fish stocks
- Fish quotas
- Net size
Fish quotas
- Limits tn No of fish and size that can be caught in certain areas
- remaining fish can breed
- Prevents certain species from being overfished
Net size
- Limits of mesh szie on fish nets
- Bigger mesh size = let unwanted species escape, young fish escape allowing them to reach breeding age
What happens if you limit the movement of livestock and keep them in a temp controlled place?
- Reduces energy from livestock to environment
- Farming more effecient as animals use less energy moving around and more on growth, so more food produced from the same input of resources
How is food production made more effiecnet
- Livestock can be factory farmed - raising them in small pens
- Fish can be factory farmed in cages, movement restricted
- Animals fed high protein food to increase growth
Why are some farming methods controversial
- Animals kept so close- disease could spread
- Antibiotic use could cause strains of resistant bacteria
- Ethical objections - unnatural and uncomfortable and cruel to live like this
- makes them stressed = fights
- Animals should be raised in natural conditions and normal behaviour = better for welfare by reducing stress
What is mycroprotein
- Used to make high-protein meat substitue for veg meales
- Made from fungus Fusarium which is grown in aerobic conidions of glucose syrup which it uses as food
- The fungal biomass is harvested and purified to product the mycoprotein
2 advan of mycroprotein
- Suitable for vegetarians
- Very large amounts made in a small space
How can biotechnology help in crops?
- GM crops - produced to be resistant to pests - improving crop yields
- Can be genetically modified to grow better in drought conditions - crop yield improve
- Provide more nutrional value eg Golden rice modified to give vitamin a
Genetic enginerring for insulin to go in bacteria steps
- Plasmid from bacterium removed
- Insulin gene cut out using restrictive enzyme from human chromosome.
- Restriction enzyme recognise specific sequences of DNA and cut DNA at these poits - cut leaves one of dna strands with unpaired bases (sticky end)
- Plasmid cut open using same r. enzyme
- Plasmid and human insulin gene mixed together
- Ligase (enzyme) added. joins sticky ends to produce recombinant DNA
- Recombinant DNA inserted into bacterium
- Modified bacterium grown in a vat under controlled conditions - millions of bacteria produce inslun which can be harvested and purified to treat diabetes
Why do some ppl disagree with biotech and crops (GM)
- Ppl go hungry cant afford to buy food, not becuase there isnt any food about. Tackle poverty first
- Fears that countries may become dependant on companies who sell GM seeds
- Poor soil is the reason why crops fail, ven GM crops wont survive
Waste products of decomposers
- CO2
- Water
- Nutrients - Nitrogen , phosphurus, potassium
Why is decay important?
- Nutrient recycling - breaks down dead organic material - useful nutrients bakc into soil
- Carbon cycle - releases co2 for photosynthesis
- Waste Removal - of dead bodies
- Disease control
Diff between detritivores and decomposers
- Detritivores are insectors, decomposers are microogranisms
- Decomposers break down organic matter and feed on them, detritivores eat the remains of dead material
How do you calc the rate of decay?
Change in mass (g) / time (days)
What is glucose used for after photosynthesis?
Glucose used to make amino acids / proteins / cellulose which is required for the growth of new leaves
Do microorganisms respire aerobically or anaerobically and what do they release?
Aerobically
Oxygen releases energy
What can you use decomposers for?
- To break down waste in sewage treatment plants which is released into rivers which provides correct conidiotns
- Compost
RP 10 - Decay
Why does milk go sour at room temp after a few days?
- Bacteria uses enzyme to produce acidic molecules
- Makes milk acidic
Why cant we do the decay practical in school?
Decay is a slow process
RP 10 - Decay
Required Practical 10 - Decay (Effect of temp on the decay of milk) Steps
- Label test tube lipase
- Use pipette to add 5cm3 lipase solution
- Label other test tube milk abd add 5 drops of Cresol Red indicator
- Add 5cm3 milk and 7cm3 sodium carbonate to milk test tube
- Solution will be purple because Cresol Red is purple in alkaline conditions due to sodium carbonate
- Place thermometer in test tube
- Places both tubes into beaker of water at chosen temp (20c)
- Wait till tem p of solutions = same as water
- Use pipette and transfer 2cm3 lipase solution to milk Test tube and stir
- Start timer, lipase will break down fat molecules
- Releases fatty acids, milk becomes acidic
- In acidic conditions, indicator is yellow
- When its yellow, stop timer and record results
- Repeat at range of diff temps
- Plot graph
RP 10 - Decay
What is the IV, DV and CV?
IV = Temperature
DV = Time taken for milk solution to turn yellow
CV = Volumes of diff solutions like Cresol Red, lipase, milk, sodium carbonate solution
RP 10 - Decay
Why should you use a clear test tube for milk solution for each experiment?
Any traces of lipase from previous experiment will trigger reaction before ready if we dont
RP 10 - Decay
Why should you share data and calc mean?
Looking for change in colour, difficult to decide exact point to stop timer
What is carbon used in plants and algae?
to make carbs fats and proteins which make up the cells
Why are compost heaps warm?
- Decomposers release energy
- during aerobic respiration
What does mixing compost also do?
Breaks up large clumps and increases SA for decomposers to act on
What happens do decomposition when there is no oxygen?
- Microorganisms carry out anerobic decay
- which produces mixture of gases including methane
- Biogas
What can small-scale biogas generators be used for?
to provide fuel for homes - often use plant materials eg food waste/manure
Why is a great biodiversity important?
ensures stability of ecosystems by reducing the dependence of one species on another for food, shelter, etc
What is deforested land used for?
- rice fields
- grazing cattle
- grow crops used to make biofuels
What can fertilisers and untreated sewage cause if accidently released into rivers?
- cause dissolved oxygen levels to fall
- kill aquatic animals
Why is dry biomass more useful than wet biomass?
Moisture content of organisms can vary widely and produce inaccurate results
How would you get dry biomass?
Look up the data in scientific journals
Pyramid of Biomass order
Top = apex predator = smallest
bottom = producers = largest
Pros of factory farming
- more efficient as less biomass is wasted by respiration
- control of the food - so more nutrients and less wasted
- more easily harvested if indoors (chicken eggs)
How does modern biotechnology enable?
- enables large quantitis of microorganisms to be cultured for food
- genetically modified bacterium produces human insulin. When harvested and purified this is used to treat people with diabetes.
How would you find the total number of diasies?
mean in 1X1m X area of field
How would you avoid bias in quadrats
random number generator for coordinates
