3b Flashcards
How does waste affect water?
Sewage and toxic chemicals from industry can pollute lakes, rivers and oceans, affecting the plants and animals that rely on them for survival. And the chemicals used on land can be washed into water
How does waste affect land?
Toxic chemicals are used for farming. Also bury nuclear waste underground, and dump a lot of household waste in landfill sites
How does waste affect air?
Smoke and gases released into the atmosphere can pollute the air e.g sulfur dioxide can cause acid rain
What are the four main human activities that reduce the amount of land and resources available to other animals and plants?
Building, farming, dumping waste, quarrying for metal ores
Give three examples of where co2 can be sequestered in natural stores
Oceans, lakes, ponds & green plants as carbon compounds & peat bogs
What are the gases in the atmosphere that help to keep the heat in called?
Greenhouse gases
How do the gases in the atmosphere act like an insulating layer?
They absorb most of the heat that would normally be radiated out into space and re-radiate it in all directions
Give three reasons why deforestation happens
To provide timber to use as building material, clear more land for farming, produce paper from wood
What are the four main problems deforestation?
Puts more methane into the atmosphere, more carbon dioxide in the atmosphere, less carbon dioxide taken in, less biodiversity
How does deforestation cause more methane in the atmosphere?
Decomposers produce methane, cattle produce methane (space for farming)
How does deforestation cause more carbon dioxide in the atmosphere?
Released when the trees are burnt to clear land, microorganisms feeding on dead wood release carbon dioxide from respiration
How does deforestation cause less carbon dioxide to be taken in?
Cutting down loads of trees means that the amount of carbon dioxide removed from the atmosphere during photosynthesis is reduced
How does deforestation cause less biodiversity?
Destroys habitats, food
What is biodiversity?
The variety of different species in a habitat
What are the consequences of global warming?
Sea levels rise, changed weather patterns (more extreme weather), biodiversity reduced, changes in migration patterns
Why do sea levels rise due to global warming?
As sea gets warmer it expands, higher temperatures make the ice melt
Why does global warming affect weather patterns?
Hurricanes (water warmer than 27c), cloud formation, water vapour
What is fermentation?
When bacteria or yeast break sugars down by anaerobic respiration
How is ethanol made?
The anaerobic fermentation of sugar
What is the word equation for the break down of glucose by anaerobic respiration?
Glucose-> Ethanol + Carbon dioxide + Energy
What is biogas made out of?
70% methane 30% carbon dioxide
How is biogas made (short)?
Anaerobic fermentation of waste material
How is biogas made (long)?
Different microorganisms used to ferment plant and animal waste which contains carbohydrates in a digester/ generator
What are the two types of biogas generators?
Batch and continuous generators
What happens in a batch generator?
Manually loaded with waste, left to digest, byproducts cleared away at the end of each session, makes biogas in small batches
What happens in a continuous generator?
Waste is continually fed in and biogas is produced at a steady rate, more suited for large-scale because make biogas all the time
What 3 things does a batch generator need?
Inlet for waste material, outlet for digested material, outlet for biogas to be piped out
What four factors do you need to consider when designing a generator?
Cost, convenience, efficiency, position
Name 3 advantages of biofuels
Carbon neutral, no acid rain, methane not released
How can the efficiency of food production be improved?
Reducing the number of stages in the food chain, restricting the energy lost by farm animals, developing new food sources like mycoprotein
What doe mycoprotein mean?
Protein from fungi
Why is the main source of mycoprotein?
Fusarium
How is the fungus grown?
In fermenters, using glucose syrup as food. Glucose syrup obtained by digesting maize starch with enzymes. Fungus respires aerobically, oxygen supplied with nitrogen and other minerals, everything sterilised before coming in- mycoprotein is then harvested and purified
How can fish stocks be maintained (conserved)?
Fishing quotas, net size
