Biology B3 Part 2

Based on Edexcel Textbook

pg 18-19 Feeding the World

7 billion people live on the planet and we all need food to eat. Plant breeding programmes can be used to produce a higher yeilding crop or a more disease resistant ine. New varities are produced by cross breeding two existing species (hybridisation). This has boosted yeilds by 25% since the 1970's. The process takes 10 years but programmes that used genetic engineering fast track this meaning more and better food is available quicker especially useful in developing countries.

Another use of biotechnology to produce more food is fermenters where Single-cell protein (SCP) can be produced from microorganisms. It is useful because it grows fast (mass can double within hours) and is high in protein, vitamins and minerals. It also takes up little space and is not reliant on weather BUT there are downsides. The microorganisms need certain conditions meaning technology and energy is needed which can be out of the range of developing countries. The microorganisms also need nutrient supply to grow. Example od SCP Quorn.

pg 20-21 Genetically modified plants

Weeds are a problem to farmers (compete with crops) so herbicides are used to kill them. The problem is these can also kill the crops. Some plants have a gene making them herbicide resistant. Genetic engineering can be used to put this gene into the crop so that it is not effected by the herbicide. The bacteria Agribacterium Turnefaciens lives in the soil and in the 1980's it was first used as a vector to transfer the gene.

Method:

• Herb resistant gene cut out of plant using restriction enzyme
• Agribacterium plasmid (circle of DNA) taken out and cut open and ligase enzyme used to stick the herb resistance gene in.
• Plasmid…