Topic 20 Flashcards
Give 5 ways that modern technology has aided food production
“New efficient machines can work over larger areas
Improved fertilisers to boost crop yields
Insecticides prevent crops from being destroyed by insects
Herbicides stop competition from weeds for resources
Desirable features chosen through selective breeding”
State the advantages of monocultures
It’s more efficient farming with the same fertilisers and equipment, it produces and higher yield, cheaper for consumers
Give one reason why monoculture is bad for ecosystems
Monoculture reduces biodiversity significantly, so if one organism for example became susceptible to a disease then they all would be
State the advantages of intensive farming of livestock
Animals use less energy moving around and controlling temerature so more energy used for growth leading to more profit
State the negative environmental impacts of intensely farming livestock
“Water pollution, spread of disease, Soil and land quality is decreased
“
State 2 social issues with providing sufficient food for
“Land used for agriculture could be used for housing or leisure facilities
Machinery used for agriculture can be loud and may become an issue for people who live nearby”
Describe 3 human activities that cause habitat destruction
“Deforestation for timber production, housing and farming
Extraction of natural resources requires clearing land and large machinery
Marine pollution from oil spills, waste, eutrophication and plastic waste is damaging to aquatic life and the habitat they live in”
Give 4 undesirable effects of deforestation
“Extinction
Erosion of soil
Increased risk of flooding
Increased atmospheric carbon dioxide”
Explain how deforestation causes extinction
“Deforestation removes food and shelter for animals
Animals without food or shelter are less likely to survive, leading to extinctions”
Explain how deforestation leads to soil erosion
“Tree roots anchor soil and the trees shelter and protect the soil which prevents erosion
Deforestation leaves the soil exposed and erosion happens more quickly”
Explain how deforestation leads to an increased risk of flooding
“Trees absorb water which evaporates off their leaves, leaving the ground drier and able to absorb more water
Less trees increases surface runoff and the risk of flooding”
Explain how deforestation leads to increased carbon dioxide levels
“Trees take in carbon dioxide from the atmosphere during photosynthesis which decreases atmospheric carbon dioxide levels
When trees are cut down, the atmospheric carbon dioxide is no longer absorbed and so level remain higher”
State 5 sources of water pollution
Insecticides, Herbicides, Sewage, Waste (plastics, chemicals, metal), Nuclear fallout
State 4 sources of air pollution
“Vehicle exhaust
Home heating
Industrial fossil fuel burning for generating power
Manufacturing processes”
What is eutrophication?
An excess of nutrients in a body of water, often due to fertilisers in the water source
Why is eutrophication bad for aquatic life?
It causes an ‘algal bloom’ which decreases oxygen supplies in the water and degrades the water quality
Describe the process of eutrophication
“Often caused by leaks of fertilisers containing nitrate and other ions into the water source
Increased growth of producers (e.g. algae which is called an algal bloom)
Increased decomposition after death of producers (due to lack of light) by decomposerswhich use up dissolved oxygen during respiration
Organisms that need the oxygen in the water begin dying”
What is meant by non-biodegradable waste?
Waste which cannot be broken down naturally in the environment (e.g. by erosion or decomposers)
Describe the effects of non-biodegradable plastics
“Chemicals in the plastics can leach out and cause damage to organisms
Animals can get trapped in plastics, leaving them vulnerable (e.g. to predators or starvation)
Animals can swallow plastics, causing blockages and often death”
State 3 sources of methane in the atmosphere
“Biomass burning
Livestock production systems
Decaying matter in landfills”
What does excess atmospheric methane and carbon dioxide cause?
“Methane and CO2 are greenhouses gases
Excess greenhouse gases lead to thegreenhouse effect where heat is trapped by the gases
This leads to global warming”
State 3 negative consequences of global warming
“Sea level rise caused by melting icebergs
Disrupted farming and agriculture
Increased spread of diseases in warmer climates”
Explain how excess methane and carbon dioxide causes global warming
“The gases accumulate in the atmosphere and absorb the thermal energy from the sun
This traps the extra heat energy in the atmosphere and warms the earth”
