Biological knowledge and society Flashcards
Define gene cloning
Gene cloning is a powerful gene technology that uses DNA manipulation techniques. Gene cloning allows scientists to produce exact copies of a gene of interest
Gene cloning
Process - - - - -
- Treat some plasmids with a restriction enzyme with sticky ends.
- Treat the gene of interest with the same restriction enzymes. The sticky ends produced will be complementary to that of the plasmids, since we used the same restriction enzymes.
- Mix the treated plasmids and the gene DNA together and add ligase (glue). The plasmids are now recombinant.
- Use either electroporation or heat shock therapy to force the bacteria to uptake the plasmid into their cytoplasm (transformation)
- The bacteria will multiply by binary fission
- We can isolate the protein of interest
Gene cloning
Social implications may affect people’s financial position, lifestyle and reproductive decisions. - - - -
- Reduced cost of therapeutic made with bacteria
- Wider access to treatment
- Employment opportunities in the biotechnology industry
- Misuse for non-therapeutic purposes
Gene cloning
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- Human recombinant proteins more effective than protein purified from other animals
- Risk of contamination by bacterial molecules
- New, safer vaccine possible
Gene cloning
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- Use of bacteria fro therapeutic addresses philosophical, cultural or religious objections to animal use.
- Manipulation or shifting of genes may be seen as unethical, regardless of purpose.
Define genetically modified organisms
Create organisms whose genomes are manipulated (artificially altered)
What are the two ways by which organisms can be genetically modified
- A foreign gene (from different species) can be inserted (transgene) into the genome of an organism -transgenic organism (TGO)
- gene can be ‘knocked out’
Genetically modified organisms
Transgenic organisms
Mechanisms for transfection (the insertion of foreign DNA into an eukaryotic cell)
-Pronuclear microinjection
The transgene is physically injected using a very fine needle into a fertilised egg of an organism. The transfected zygote then divides to form a cluster of cells in an embryonic phase, when is then transferred into a female. The embryo develops into a new organism whose cells will all have the transgene
Genetically modified organisms
Transgenic organisms
Mechanisms for transfection (the insertion of foreign DNA into an eukaryotic cell)
-Retrovirus
The transgene is inserted in RNA form into a retrovirus, which is then introduced into an existing organism. The virus infects the cell of the organism, and uses its reverse transcriptase and integrase enzyme do physically ‘jam’ the DNA copy of the gene into the chromosome of the host cell. (not all cells will be infected)
Genetically modified organisms
Knockout organisms
-Treatment of embryonic stem cell
The stem cells are acquired. A non-functional copy of the gene of interest is inserted via electroporation. This non-functional copy ‘swaps places’ with a functional copy of the gene in the genome (due to homologous reombination)
Genetically modified organisms
Knockout organisms
-Formation of chimera organisms
These genetically modified heterozygous stem cells are inserted into embryos. The embryo develops into a chimeric organism.
Genetically modified organisms
Knockout organisms
-Breeding
If the chimeric organism reproduced the genetically modified cells can be crossed into the offspring.
Genetic modification in agriculture advantage - - - -
- Increase crop output
- Allow plants to survive under challenging environmental conditions
- Increase the nutritional value of certain foods
- Provide plants with resistance to insects, certain diseases and herbicides
Genetic modification in agriculture
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- Methods include shooting heavy metal particles coated in the DNA of interest into the plant cell using a gene gun.
- The latter method involves recombinant DNA technology where a transgene is inserted into the Ti plasmid of the bacteria which when infect the plant and enable the gene to be incorporated into the plants DNA
Biosocial and ethical implications for GMOs - - - - - - -
- The use of GM crops could lead to a decrease in the genetic diversity, further affecting the organism in that environment.
- Gene flow between GM and non-GM plants must be considered (could changes be passed onto non GM crops or plants growing in the wild)
- There is the potential for insects to become resistance to the insecticides incorporated into GM crops
- GM food could negatively impact ones health
- GM crops that have been nutritionally fortified an provide benefits to communities affected by malnutrition.
- Some individuals are opposed to humans manipulating the DNA of any organism
- A small number of companies control much of the GM crop technology available.
