Ecology and the Environment Flashcards
Describe how you could use a quadratic to estimate the plant biomass in a region
1) random coordinates generated
2) several quadrants
3) weigh/method of weighing
4) remove animals/soil
5) multiply to total area/scaling
What is meant by the term environment?
the sum of the total non-biological components of the ecosystem
What is meant by the term population?
Number of organisms of the same species
What is meant by the term community?
all of the populations of living organisms living in an ecosystem at a particular time
What is meant by the term habitat?
The place where organisms live
What is meant by the term ecosystem?
a distinct, self supporting system of organisms interacting with each other and with their physical environment
what are the biotic factors which affect organism numbers?
1) disease
2) competition
3) food availibility
what are the abiotic factors which affect organism numbers?
1) temperature
2) humidity/rain
3) sunlight
4) pesticides
What is meant by the term trophic level?
the position of an organism in the food chain
What is meant by the term producer?
plants which photosynthesise to produce food
What is meant by the term consumer?
animals that eat plants or other animals
What is meant by the term decomposer?
organisms which decay dead material and help to recycle nutrients
why isn’t all energy transferred from one trophic level to the other?
1) some energy is lost during respiration
2) some energy is lost during excretion
3) some energy is lost during egestion
4) some energy is lost during movement
5) some energy is lost during heat loss (thermoregulation)
6) not all of each organism is eaten
7) some organisms die
Other than carbon dioxide and methane name 3 greenhouse gases
1) water vapour
2) CFCs
3) nitrous oxide
What are 5 advantages of using biological control rather than pesticide?
1) last longer
2) no reapplication
3) specific
4) avoids bioaccumulation
5) no development or resistance
Describe the process of eutrophication
1) algae bloom
2) algae block light
3) plant death so less photosynthesis
4) bacteria/decomposers
5) respiration
6) oxygen depletion
7) death of fish
Describe the consequences of an increase in carbon dioxide for the world’s ecosystems
1) greenhouse effect
2) global warming
3) melting ice caps
4) climate change
5) loss of habitat
6) extinction
7) migration (spread of disease/pests)
Suggest why animals prefer to eat plants in some habitats rather than habitats
1) more nutritious
2) easier to digest
3) fewer other animals (competition)
4) fewer predators
Suggest how countries can reduce the impact of deforestation
1) laws to limit deforestation
2) plant more trees
What is the process in the nitrogen cycle which goes from nitrate ions to nitrogen gas?
Denitrification
What is the process in the nitrogen cycle which goes from nitrogen gas to ammonium ions?
Nitrogen fixation
What is the process in the nitrogen cycle which goes from nitrite ions to nitrate ions?
Nitrification
Which organisms carry out denitrification?
Denitrifying bacteria
What are the effects of adding too much nitrate to soil?
1) leaching
2) eutrophication
3) loss of water from plant roots
How can farmers increase the fertility of soil?
1) chemical fertilisers
2) manure
3) legumes
How can you make sure your results are reliable?
1) repeat
2) calculate average
3) discard anomalies
What is the water cycle powered by?
Energy from the sun
What are the biological consequences of pollution of water by sewage?
Increases in the number of microorganisms causing depletion of oxygen
What are the four stages of the water cycle?
1) precipitation (from clouds)
2) transpiration (from trees) and evaporation (from large bodies of water e.g. lakes and the sea)
3) condensation (forming clouds)
What is the process by which carbon goes from animals and plants into the atmosphere?
Respiration
What is the process by which carbon goes from the atmosphere into plants?
Photosynthesis
What is the process by which carbon goes from dead matter into the atmosphere?
Decomposition
What is the process by which carbon goes from fossil fuels to the atmosphere?
Combustion
What do nitrogen fixing bacteria do?
Convert nitrogen gas into ammonia (which is then used to make proteins in plants)
What does decomposition do in the nitrogen cycle?
Produces ammonia by breaking down dead protein matter
What do nitrifying bacteria do?
Oxidise ammonia to nitrites and the nitrates (which can then be absorbed and assimilated by plants)
What do denitrifying bacteria do?
Break down nitrates into nitrogen gas
What are the effects of deforestation?
1) leaching
2) soil erosion
3) disturbance of the water cycle
4) disturbance of the balance of atmospheric oxygen and carbon dioxide
name the type of bacteria that live in the root nodules of legumes
nitrogen-fixing bacteria
describe how ammonium ions can be converted to nitrate ions in the soil
1) nitrifying bacteria
2) nitrite ions to nitrate ions
Describe how the process of nitrification affects the availability of nitrates to plants
1) Nitrifying bacteria
2) ammonia to nitrites and then nitrates
Suggest why farmers grow legume crops and then plough them into the soil before growing their cereal crops
1) root nodules
2) nitrogen fixing bacteria
3) nitrogen gas to nitrates
4) amino acids/proteins
5) growth/higher yield
6) decomposition
7) decomposing bacteria/fungi
8) mineral ions
explain how the nitrogen in a nitrate ion in the soil can become the nitrogen protein in an animal
1) absorption by roots/root hair cell
2) active transport
3) make amino acids
4) assimilation
5) plant is eaten/ingested by animal
6) digestion
7) protease
suggest advantages of using animal waste as a fertiliser rather than using a chemical fertiliser
1) cheaper
2) less eutrophication/leaching
3) improves soil structure (stops erosion)
