Genetic Modification Flashcards
Genetic modification definition
The changing of genetic material in an organism by removing, changing or inserting individual genes
GM advantages over selective breeding
Genes from different species can be combined (not restricted to alleles in a natural population)
Increases allelic diversity
Transgenic definition
The transfer of genetic material from one species to a different species
Restriction enzymes function
Cut DNA at specific points - different types will recognize and cut different base sequences
DNA from 2 organisms must be cut with the same restriction enzyme (otherwise fragments won’t match up)
Cutting DNA creates ‘sticky ends’ that can pair with another end with complementary bases
DNA ligase function
Enzymes that act like molecular glue to join cut ends of DNA molecules together
Vector definition
Structure which can be used to transfer genes in genetic engineering
What can act as vectors for genetic engineering
Plasmids (transfer DNA into bacteria or yeast)
Viruses (transfer DNA into human cells or bacteria
Describe the process of using bacteria in genetic engineering to produce human proteins [5]
The human GENE that codes for human protein is identified
The gene is removed using RESTRICTION enzymes
This will form COMPLEMENTARY/STICKY ends
A plasmid is cut using the SAME restriction enzyme
The human gene is INSERTED into the plasmid
DNA LIGASE is used to join the gene with the plasmid
The recombinant plasmids are INSERTED into bacteria
The bacteria REPRODUCE
Transformed bacteria can be IDENTIFIED/PURIFIED
Use of vectors
The genetically engineered plasmid is INSERTED into a BACTERIAL CELL
When the bacteria reproduce the plasmids are COPIED too, the recombinant plasmid can SPREAD QUICKLY
They all EXPRESS THE GENE and make the desired compound
The bacteria can be placed in a FERMENTER to reproduce quickly in controlled conditions and make LARGE QUANTITIES
Human insulin
Insulin helps move glucose from the blood into cells for respiration
Can be used to treat people with diabetes as they cannot produce enough insulin themselves to control blood glucose levels
Process of producing insulin from GM bacteria
GENE for insulin production is located within a HUMAN chromosome
RESTRICTION ENZYMES cut out the human insulin gene, leaving it with ‘STICKY ENDS’
A bacterial PLASMID is cut by the SAME restriction enzyme, leaving it with corresponding sticky ends
The plasmid and the isolated human insulin gene are joined together by DNA LIGASE
The recombinant plasmid is INSERTED into a BACTERIAL cell
When the bacteria reproduce, the plasmids are COPIED and can be Q UICKLY SPREAD
All the new bacteria EXPRESS THE HUMAN INSULIN GENE and make the HUMAN INSULIN protein
The bacteria can be placed in a fermenter to reproduce quickly in controlled conditions
Why are bacteria useful for genetic engineering purposes
They contain the SAME GENETIC CODE as the organism the genes are being taken from so they can easily read it and PRODUCE THE SAME PROTEINS
There are NO ETHICAL CONCERNS
The PRESENCE OF PLASMIDS makes them easy to remove and manipulate to insert genes
Advantages of GM crops/plants
Reduced use of chemicals such as herbicides and pesticides - better for environment
Cheaper/less time-consuming for farmers
Increased yield as they are not competing with weeds for resources or suffering from pest damage
Resistance to certain herbicides and pests
Disadvantages of GM crops/plants
Increased costs of seeds as development cost of GM seeds are higher - poorer farms cannot compete
Risk of inserted genes being transferred to wild plants by pollination, reducing usefulness of GM crop
Reduced biodiversity as there are fewer plant species when herbicides have been used
Some research has shown GM plants do not grow as well as non-GM plants
