ecology Flashcards
What is an ecosystem?
Interaction of a community of living organisms with non-living parts of their environment
What is interdependence?
In a community, each species depends on another species, for things such as food and etc
What are the abiotic factors that affect a community?
Moisture levels Light intensity Temperature CO2 levels Wind intensity and direction Oxygen levels Soil pH and mineral content
What are the biotic factors that affect a community
Availability of food
New predators arriving
New pathogens
Competition- species out-competing another so numbers are too low to breed
What are structural features?
Features of an animal’s body
What are behavioural features?
The way organisms behave
What are functional features?
Things that go on inside an organism’s body that can be related to processes like reproduction
What is the chain of consumers?
Producer —–> primary consumer ——> secondary consumer ——-> tertiary consumer
How do you do sampling?
Randomly place quadrat on field and count no. of daisies
Use random coordinates to place quadrat in 10 random locations
Calculate mean from 10 samples
Multiply mean by area of field
How do you use a quadrat?
Lie 30m tape along field- transect line
Place quadrat every 0,5,10,15m…
Count no. of daisies in each quadrat
Calculate mean
How do you find the mean?
Total no. of organisms/ No. of quadrats
What environmental changes can affect the distribution of organisms?
Temperature
Availability of water
Composition of atmospheric gases
What is the water cycle?
Energy from sun makes water evaporate
Water vapour cools and condenses
Water falls from clouds as precipitation
Drains back into the sea
What is the rate of decay affected by?
Temperature
Water availability
Oxygen availability
No. of decay organisms
Why does temperature affect decay?
Hotter= enzymes work faster
Too hot= denature
Too cold= enzymes don’t have enough energy
Why does water availability affect decay?
More moist= easier to digest food+ grow faster
Why does oxygen availability affect decay?
Need oxygen to break down food, transfer energy to grow+ reproduce
Oxygen = faster
Temperature affecting decay practical
Add 5cm3 of lipase to test tube Add 5cm3 of milk to different test tube Add 5 drops of phenolphthalein to milk Add 7cm3 of sodium carbonate to milk Both test tubes in water bath of 30degrees Put 1cm3 of lipase in milk Start stopwatch Soon as loses colour stop time Repeat with different temperatures
What is phenolphthalein?
Indicator that’s pink in pH 10 and becomes colourless when pH below 8.3
What is biodiversity?
The variety of different species of organisms on Earth or withing an ecosystem
What human activities impact biodiversity?
Waste management
Land use
Global warming
Deforestation
Why does deforestation cause problems?
Less CO2 is taken in
More CO2 is released into the atmosphere
Less biodiversity as habitats are destroyed
How does breeding programmes maintain biodiversity?
Species bred in captivity to prevent extinction
How does habitat protection maintain biodiversity?
Protect and regenerate rare habitats like coral reefs
reintroduce hedgerows and field margins where only one type of crop is grown
How does reducing waste maintain biodiversity?
Encouraged to recycle rather than going to landfill
What conflicting pressures affect maintaining biodiversity?
Costs of programmes
Effect on local economy
Protecting food security
Development of society
What does each bar on a pyramid of biomass show?
Their relative mass of living material
What should you always do to each bar?
Label it
How do you calculate the efficiency of biomass transfer?
Biomass transferred to next level
——————————————————– X100
Biomass available to the previous level
What is food security?
Having enough food to feed the whole population
What are the factors affecting food security?
Increased birth rate
Changing diets
Conflicts
Cost of agriculture
How can fish stocks be maintained?
Fishing quotas
Net size
Why does fishing quotas help food security?
Limits number and size of fish that can be caught in an area
Prevents certain species being over-fished
Why does net size help food security?
Using bigger mesh let unwanted fish escape
Younger fish will slip through net allowing them to breed
How does limiting movement of livestock make food production more efficient?
Reduces transfer of energy so more energy is available for growth
How do fertilisers used by farmers affect water systems?
Contain nitrates Washed off fields into streams Increased nitrate in water cause algae to grow Plants die coz of competition for light Increase in microorganisms feeding on dead plants Decrease of oxygen levels in water Animals die to lack of oxygen Called eutropication
What fungi is used to make high protein meat substitutes?
Mycoprotein
How does land use reduce biodiversity?
Population grows= more buildings= more habitat destroyed to make room
Quarrying= habitats destroyed
Farming= pesticides + water pollution
Peat bogs destroyed= plants, animals and bacteria killed
