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Biology AS Edexcel Snab Revision

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Exam code:8BN0

Sustainability & Plant Materials

  • Sustainability refers to the using resources in such a way that the requirements of the current generation are met without depleting these resources for future generations

  • This requires the use of renewable resources – which can be used without the resource running out

    • An example would be solar energy – it will not run out in our lifetime as the sun will continue to shine every day for several billion more years

  • Fossil fuels are an example of a non-renewable resource, as they could potentially run out if we use them too fast (since it takes millions of years for fossil fuels to form)

  • Sustainable practices are those that minimise the damage done to the environment and its resources, to ensure that there will be something left for the next generation

    • An example would be replanting trees after logging

  • Unsustainable practices are limited by a finite supply of resources

    • An example is the use of fossil fuels to make oil-based plastics

Plant fibres and Sustainability

  • Using plant fibres to make products such as ropes and fabric is more sustainable than using oil-based plastics

  • Less fossil fuels are used and plants can be replanted for the next generation

  • Plant fibres are biodegradable, unlike most oil-based plastics, which means the products made from these fibres can be broken down by microbes to minimise environmental pollution

  • Extracting and processing oil is an expensive and difficult procedure compared to growing and processing plants, making plant-based products easier and cheaper to produce in developing countries

  • However, the ropes made from plant fibres are typically not as strong as plastic ones

Starch and Sustainability

  • Plants store excess sugars as starch in their cells

  • Starch can be used to make bioplastics which is more sustainable than making oil-based plastics

  • It does not require as much fossil fuels to be burned to produce them and the crop plants can be replanted (renewable resource)

  • Starch can also be used to make bioethanol, which can be used as a fuel for vehicles

  • Using starch to produce biofuels is more sustainable than producing them from oil

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