human influences on environment and use of biological resources rev Flashcards
consequences of SO2
Acid rain - damages plants, increases soil pH, wears away bridges
Respiratory problems
consequences of CO
binds to haemoglobin in preference to O2 - suffocation and death
name the greenhouse gases
water vapour, carbon dioxide, nitrous oxide, methane and CFCs
how does human activity lead to more greenhouse gases
burning fossil fuels - more CO2
cattle production - more methane
rice paddy fields - more methane
describe greenhouse gas effect
- the Sun emits rays that enter the Earth’s atmosphere
- heat bounces back from the Earth’s surface as infrared radiation
- some heat is reflected back out into space
- some heat is absorbed by greenhouse gases and is trapped within the Earth’s atmosphere, excess greenhouse gases mean earth’s temp increases
impacts of global warming
- Ocean temperatures increasing, causing melting of polar ice caps / rising sea levels / flooding / coral bleaching
- Increasing temperatures causing extreme weather like super storms, flooding, droughts
- Changes in or loss of habitats due to these extreme weather events
- Decreases in biodiversity as food chains are disrupted and extinction rates increase
- Increases in migration of species to new places, including increased spread of pests and disease
what happens when fertilisers leach into water
eutrophication
effects of sewage pollution
sewage - aerobic bacteria feed on it - reduce oxygen levels in water - other organisms die
impacts of deforestation
- leaching - soil minerals washed away by rain, not taken up
- soil erosion
- disturbance of the water cycle - reduces transpiration
- disturbance of the balance in atmospheric oxygen and CO2 - less photosynthesis, more CO2
how do glasshouses increase crop yield
- Artificial heating (enzymes controlling photosynthesis can work faster at slightly higher temperatures - only used in temperate countries such as the UK)
- Artificial lighting (plants can photosynthesise for longer)
- Increasing carbon dioxide content of the air inside (plants can photosynthesise quicker)
- Regular watering (irrigation)
how do polythene tunnels increase crop yield
- More commonly called polytunnels, these are large plastic tunnels that cover crops
- They can protect crops grown outside from the effects of the weather, including excessive wind, rain and extreme temperatures
- They also increase the temperature slightly inside the tunnel
- They can prevent the entry of pests that can damage plants or diseases that can kill plants
what are the limiting factors of photosynthesis
temp, light intensity, CO2
what do plants need nitrogen for
- Absorbed in the form of nitrates
- Needed to make amino acids which are the building blocks of proteins
two types of fertiliser and what fertilisers are for
organic and chemical, used to provide more mineral ions, so plants grow bigger and faster and yield increases
what do plants need phosphorous for
- Absorbed in the form of phosphates
- Needed to make DNA and cell membranes
what do plants need potassium for
- Absorbed in the form of various compounds of potassium
- Allows enzyme reactions to take place to produce ATP in respiration as well as being needed for the enzymes involved in photosynthesis
two methods of pest control
Pesticides (chemical that kills)
Biological control (intro of a predator)
advantages of pesticides
- easily accessible
- relatively cheap
- works immediately
- kills entire population of pests
disadvantages of pesticides
- target organism can develop resistance
- can kill other organisms
- bioaccumulation
- need to be repeatedly applied
what is bioaccumulation
When pesticides don’t break down in body and accumulate in body of predator top of food chain
advantages of biological control
- no pollution (natural)
- no resistance
- can target specific species
- long lasting
- no need to reapply
disadvantages of biological control
- may eat other organisms, not pests
- takes longer to be effective
- cannot kill entire population
- may move out of area/ not adapt to new environment
- may become a pest itself
role of yeast in beer making
Anaerobically respires (fermentation), using sugar to make ethanol and CO2
what is the role of bacteria in yoghurt making
Digests milk proteins and converts lactose (sugar) into lactic acid
what bacteria are used in yoghurt making
Lactobacillus bulgaricus
Streptococcus thermophilus
Parts of an industrial fermenters
Steam inlet/outlet pipes
Inlet pipe/ exhaust outlet pipe
Temp and pH probes
Cold water inlet and water jacket
Air inlet pipe and filter
Motor and stirring paddles
Stainless steel surrounding
Harvesting outlet pipe
how do industrial fermenters have aseptic conditions
cleaned with steam
