SB9i-j Flashcards
What is food security?
Having access to safe and healthy food at all times.
How do we increase food production?
- Improve agricultural methods
a. Using more fertilisers
b. Find/develop more productive varieties and
breeds
How does the usage of too much fertiliser pollute the environment?
- Made by chemical processes that need energy and release carbon dioxide
- Cause eutrophication
What is sustainability?
When an ongoing process continues at the same level without harming the environment.
What problems will arise if we cannot achieve sustainability due to CO2 emissions increasing?
- Global warming and climate change
- Pests and pathogens moving to a new area and destroying crops or infecting other organisms
How can we reduce CO2 emissions?
- Grow plants for biofuels (to replace fossil fuels as they are carbon-neutral)
How are biofuels carbon-neutral?
The amount of CO2 released when burned is the same amount that the plants used to make the biofuels absorbed.
What is the problem behind biofuels?
Land is needed to plant crops that make biofuel which could be used to plant crops for profit instead.
What are the 3 types of substances constantly recycled in the environment?
- Water
- Carbon
- Nitrogen
How can we represent the way water keeps moving through the ecosystem and being recycled in the environment?
Check teacher notes ‘The water cycle’ p17 diagram.
What does water that isn’t potable contain?
- Dirt
- Pathogens
- Toxic substances
- Non-toxic substances
What are 3 ways we can obtain potable water
- Desalination
- Simple distillation
- Collecting it from clouds and mist
When do we use the desalination process?
When we remove salt from sea water/salty water to get fresh water.
What is the process of desalination of water?
- Take water from the sea
- The desalination plant will make the fresh water
- Water is boiled and evaporates
- Water vapour is collected and cooled down
- Water vapour condenses and turns into liquid
- Liquid is fresh water and ready to drink
When do we use the simple distillation process?
When we get fresh water from dirty or salty water.
What is the process of simple distillation of water?
- Water evaporates as it gets heated from sunlight
- Water vapour attaches on the membrane/glass/cover and condenses
- Water slides down the cover and is collected at the end
What is the process of collecting water from clouds and mist?
- Nets are placed at high altitude areas where mist and clouds are formed
- Nets will catch the water droplets from the clouds or mist
- Water drips into the collection pipe at the base of the net
- Equipment must be clean so the water will not need any treatment afterwards
