6 ECOLOGY + ENVIROMENT Flashcards
Define an ecosystem
The community, and the habitat in which it lives
Define a habitat
The place/area where an organism lives
Define a population
The total number of individuals of one species in a particular habitat at a particular time
Define a community
All the populations of different organisms that live together in a habitat
What is an abiotic factor
Non-living factors which affect growth and survival of living things
What is an abiotic factor
Non-living factors which affect growth and survival of living things
What is a biotic factor
Living factors which affect growth and survival of living things
3 examples of abiotic factors
Temperature, sunlight intensity, mineral content in soil
3 examples of biotic factors
Disease, predetation, trampling
Describe how to investigate population size of an organism using quadrats
- Calculate area of habitat
- Measure individuals in one quadrat
- Place quadrat in 10 different locations using RANDOM SAMPLING
- Calculate average number of individuals in a quadrat
- Calculate how many quadrats fit into total area
- Multiple average number of individuals by how many quadrats fit into area
How to do a random sample
- Divide area into 0-10 co-ordinate grid
- Use a random number generator to get a pair of numbers
- Use them as co-ordinates to place your qudrat
Describe nitrogen fixation
Nitrogen-fixing bacteria in soil and roots of leagumes absorb nitrogen, and make it into ammonia
Describe nitrification
Ammonia is converted to nitrates by nitrifying bacteria
Explain denitrification
Nitrates are converted in nitrogen gas by denitrifying bacteria
Explain decompostion (as part of the nitrogen cycle)
Bacteria and fungi decompose dead matter by saprotrophic feeding, and ammonia is released into the soil
Explain decompostion (as part of the nitrogen cycle)
Bacteria and fungi decompose dead matter by saprotrophic feeding, and ammonia is released into the soil
Define Biodiversity
The measure of how many different species live in an ecosystem
How to measure the biodiversity of an area
- Calculate area of habitat
- Record number of each different species
- Place quadrat in 10 different locations using RANDOM SAMPLING
- Calculate average number of different species in a quadrat
- Calculate how many quadrats fit into total area
- Multiple average number of different species by how many quadrats fit into area
How would you investigate the effect of an abiotic or biotic variable on biodiversity
- Select at least two areas where variable is different
- Measure the variable in each area
- Estimate biodiversity using quadrat method
What is leaching
When a lot of fertiliser is washed out of the soil when it rains into a river
Describe eutrophication and the effects of leached minerals
- Nitrates are absorbed by algae in water
- Multiply rapidly and cover water - algal blood
- Blocks sunlight for other plants
- They are unable to photosynthesise and die
- Algae on surface die
- Dead remains are good source of food for bacteria
- Multiply rapidly
- Large population of bacteria respire, increaisng B.O.D, using oxygen in water
- Decreases level of oxygen for fish and they die as they cannot respire aerobically
Describe pollution of water by sewage and it’s biological consequences
- Sewage provide good source of food for bacteria
- Bacteria multiply rapidly
- Large population of bacteria respire, increasing B.O.D, using up oxygen in water
- Decreases the level of oxygen for fish and they die as they cannot repsire aerobically
What is B.O.D
Biological oxygen demand
What is the difference between eutrophication and pollution of water by sewage
Eutrophication involves an algal bloom
What does an arrow represent on a food web chart
THey dhow the direction that energy and biomass moves
Names of the trophic levels
- Producer
- Primary Consumer
- Secondary Consumer
- Tertiary Consumer
Why is the energy transfer from sun to proucers inefficent
- Light miss the plant and the chloroplasts
- Light reflected by the cuticle
- Light has wrong wavelength to be absorbed by chlorophyll
Why is only 10% of energy transferred from one trophic level to the next
- Not all the organism is eaten
- Some parts are not digested and absorbed - egested as faeces
- Energy respired and lost as heat energy
- Some plants are indigetable like lignin
Carbon cycle: respiration
Glucose broken down into carbon dioxide and released into air
Carbon cycle: eating
Carbon in food eaten and then respired back into atmosphere
Carbon cycle: decomposers
When a plant or animal dies, decomposers feed on them, and then respire the carbon into atmosphere
Carbon cycle: Combustion
Fossil fuels release carbon dioxide into the atmosphere
Name the greenhouse gases
- Water vapour
- Carbon dioxide
- Nitrous oxide
- Methane
- CFC’s
Human activities that release carbon dioxide
Burning fossil fuels and slash and burn forest clearance
Human activities that release methane
Cattle (from anaerobic activity of bacteria in their gut), and bacteria in waterlogged rice fields
Human activities that release nitrous oxides
Burning fossil fuels
Human activities that cause CFC’s
A solvent in aerosols and in fridges and freezers
Consequences of the enhanced greenhouse effect
- Melting of polar ice caps
- Destruction of habitats
- Drought and desertification
- Increased extreme weather events
- Spread of disease
- Change in crops
- Increase in heat related illness + death
Biological consequnces of pollution of air by sulfur dioxide
- The sulfur dioxide dissolves into the rainwater in the air
- The dilute acid dissolves limestone buildings
- Decreases pH of river and lakes
- Denature enzymes casuing death
Biological consequences of pollution of air by carbon monoxide
- Causes haemoglobin to bind more strongly to it than oxygen
- Less oxygen to muscles for aerobic respiration
- Can cause death
Effects of deforestation
- Leaching - mineral ions in soil run off into rivers and lakes, which can also cause eutrophication
- Soil erosion - The top soil contains the minerals are lost making regrowth of plants difficult
- Evapotranspiration - Transpiration cannot occur as there are no plants, so evaporation doesn’t occur, so rain doesn’t occur causing draughts
Consequences of the enhanced greenhouse effect
- Melting of polar ice caps
- Destruction of habitats
- Drought and desertification
- Increased extreme weather events
- Spread of disease
- Change in crops
- Increase in heat related illness + death
Describe pollution of water by sewage and it’s biological consequences
- Sewage provide good source of food for bacteria
- Bacteria multiply rapidly
- Large population of bacteria respire, increasing B.O.D, using up oxygen in water
- Decreases the level of oxygen for fish and they die as they cannot repsire aerobically
What is leaching
When a lot of fertiliser is washed out of the soil when it rains into a river
How to do a random sample
- Divide area into 0-10 co-ordinate grid
- Use a random number generator to get a pair of numbers
- Use them as co-ordinates to place your qudrat
