Ecology, Cycles and Human Influences Flashcards
Define the term population
The number of organisms of a particular species in a habitat
Define the term community
Multiple populations interacting within a particular habitat
Define the term habitat
The place where an organism lives
Define the term ecosystem
All interactions between groups of organisms in a habitat as well as the abiotic factors involved
In the food chain, identify the producer and the secondary consumer: Grass –> Centipede –>Wren –> Kestrel
Producer = Grass
Secondary Consumer = Wren
In a food chain, what do the arrows indicate?
Direction of energy transfer
Producer, primary consumer, secondary consumer etc are examples of t__________ levels
trophic
Roughly, what percentage of energy is transferred from one trophic level to the next?
10 %
Why are food chains not likely to have more than 4/5 trophic levels?
Not enough energy can be obtained by top predators as too much is lost in the food chain
What is the process by which CO2 in the atmosphere is transferred into plants?
Photosynthesis
Give 3 reasons why energy is lost between tropic levels in a food chain
Energy is lost by: movement (respiration), excretion, egestion, growth,
What is the process by which CO2 is released into the atmosphere by animals
aerobic respiration
What is the process by which carbon is converted into fossil fuels?
Death
Decay
Fossilisation
By which process is nitrogen gas converted into ammonium ions?
Nitrogen fixation
By what process are nitrates converted into nitrates by plants?
Nitrification
What organisms convert nitrates back into nitrogen gas in the air?
Denitrifying bacteria
By what process will nitrate ions be taken up by root hair cells of plants?
Active transport
By what process will dead plant matter be broken down into ammonium ions in the soil?
Decomposition
Name two pollutant gases and describe their effects
Sulfur dioxide: dissolves in rain water to form acid rain; can acidify lakes/ponds and kill marine life; can corrode marble/limestone statues
Carbon monoxide: binds irreversibly to haemoglobin
Name 4 greenhouse gases
Carbon dioxide
Nitrous oxides
CFCs
Methane
Water vapour
Name 2 human activities that can contribute to enhanced greenhouse effect
Burning fossil fuels
Deforestation
Cattle ranching
What name is given to the pollution of lakes and rivers by leached minerals from fertilisers
Eutrophication
State 3 consequences of an enhanced greenhouse effect
Global warming
Melting of polar icecaps
Habitat destruction
Extreme weather events
State 3 ways in which humans could reduce their carbon footprint
Walking
Electric/hybrid cars
Public transport
Re-forestation
Burning fewer fossil fuels
Renewable energy sources
State 3 consequences of deforestation
Leaching
Soil erosion
Disturbance of evapotranspiration and the carbon cycle
Disturbance in balance of atmospheric gases
Define the term biodiversity
The variety of different species of organisms on earth, or within an ecosystem. It includes variation within ecosystems, habitats and within/between species.
Give 3 human activities that may decrease biodiversity
Pollution
Deforestation
Global Warming
What square piece of apparatus can be used to take a sample?
Quadrat
Describe how you would study the population size of a small organisms using random sampling?
Set up grids in 2 areas
Randomly select coordinates to sample using random number generator
Count all organisms within quadrat
Repeat for 9 more pairs of co-ordinates and count up each grid
Scale up your mean values so they are representative of the whole area.
What method of sampling would you use to measure distribution across a habitat?
Belt transect (systematic sampling)
What is meant by the term abiotic factors? Give 3 examples
Non-living factors that affect communities:
Temperature
Light intensity
Soil PH levels
Carbon Dioxide concentration
Soil Moisture
Humidity
What is meant by the term biotic factors? Give 3 examples
Living factors that affect communities:
Predation
Disease
Competition for - (food/mineral ions/water/mates/space/
shelter)
