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Do you guys still remember modifying the genetic code in I/GCSE Biology?
Genetic engineering
- Genetic information in all organisms work the same way – plant, animal or bacterium
- Take gene from chromosome of one species and put it in other species = produce same CH
- Genetic engineering = the process of taking genes from one organism and putting them into the cells of another so that the cells include CH of the new gene
- When it comes to I/GCSE Biology, Genetically modified (GM) = an organism that has been genetically engineered
- Transgenic organism = an organism that contains genes from another organism
- Transfer insulin (hormone) from human into bacterium – insulin needed for diabetic people
- Bacteria fermenters grow genetically modified bacteria on large scale = human insulin cheaper + safer
- Insulin extracted from dead animals before GM human insulin = less insulin available + not identical o human insulin = health problems
- Insert gene into body cell of early embryo – body cells make what gene codes for = genes not passed to offspring
Transferring genes at an early stage
- Genes transferred into plan or animal embryo at early stage
- Refer to I/GCSE Biology, Organism grows = all cells in body have copy of inserted gene – all develop CH
- Used for GM food plants + research in causes + treatment of disease
- Mice GM to study human cancers + see effect of changes to genes causing disease
Making GM crops
Bacterium called agrobacterium used – gets gene inside nucleus of cells, then joins with cell’s DNA
Different modifications
- Herbicide – a chemical that kills plants, used to treat weeds in crops
- Some GM crops have gene for herbicide resistance
- Plants compete for water + nutrients
- Weed plants reduce amount of food harvested
- Herbicides damage weed plant
- Crops resistant to herbicide = crops sprayed by herbicide = kills weeds + crop not damaged
- Crops modified with poison which kills insects that eat plants – reduces damage to crops in yield
The pros and cons of GM crops
- GM crop seeds cost more
- Companies producing seed for herbicide resistant crops also produce the herbicide the crop is resistant to – good for company, not for farmer
- Concern – gene transfer through pollination – happens occasionally between close related plants, the gene for herbicide resistance could be transferred to the weed crops
- People concerned about safety of food produced from GM crops (tested on animals)
That's all~
