genetic engineering (B6.1) Flashcards
what does genetic engineering involve?
taking a copy of a gene frm one organism and inserting that gene into the DNA of another organism, to create a genetically modified organism or transgenic organism.
Describe the process of genetic engineering in bacteria
- a useful gene is cut from the DNA of one organism using a restriction enzyme which breaks the bonds between nucleotides.
-restriction enzymes cut DNA in a staggered way leaving ‘sticky ends’ (short sections of single-stranded DNA.
-the bacterial plasmid DNA is removed and cut using a restriction enzyme leaving sticky ends.
-the useful gene and plasmid DNA mix and gene is inserted, Hydrogen bonds form between complementary bases.
-DNA ligase is used to join the plasmid DNA end and useful gene ends together.
-recombinant plasmid inserted back into bacterial cell.
why when genetic engineering bacteria cut with the same restriction enzyme?
so sticky ends on the plasmid will have a short sequence of bases that are complementary to those on the useful gene.
After DNA ligase is applied what is the new plasmid called?
recombinant plasmid. Altered DNA from more than one source.
why is the technique used to genetically modify plant cells different to bacteria?
because plant cells don’t have plasmids
why is the bacteria, Agrobacterium tumfaciens commonly used to create genetically engineered plants?
this bacteria has Ti plasmid. When infecting plants, the Ti plasmid can enter plant cells and a proportion can enter the plant genome.
Describe the process of genetically engineering plants using a Ti plasmid
1)A recombinant Ti plasmid is created by inserting a useful gene
2)The plasmid is inserted into A.tumfaciens to create a transgenic bacterial cell.
3)Plant cells grown in the lab are mixed with transgenic A. tumefaciens. The Ti plasmid carries the useful gene into the plant cell and inserts it into the cell’s chromosomes.
4)Plant cells are grown in a culture and develop into plants.Each GM plant is able to produce the code by the useful gene
Uses of genetically engineering bacteria?
-hormones used to create insulin
Uses of genetically engineered plants?
pest, herbicide, disease resistance or ability for plants to produce nutrients to help prevent malnutrition (e.g golden rice)
what are the benefits of using GM in medicine?
- can be used to produce medicine (insulin, penicillin)
-can create larger quantities of medicine
-few side effects
-can be used to develop vaccines (e.g hepatitis)
-GM insects can reduce spread of disease (e.g malaria)
–GM using gene therapy may cure genetic diseases
what are the disadvantages of genetic modification?
-GM pigs can be used for organ donation however there could cause a spread of disease from pigs but also ethical reasons (religion) for rejection
-GM insects may affect success of wild population of insects.
-GM using gene therapy may cause cancer if not accurately inserted
How are genetically modified mosquitoes created?
Scientists can genetically modify Anopheles mosquitoes so they have a more efficient immune response when infected with the malaria parasite.
how is gene therapy carried out?
the therapeutic gene is inserted into the chromosome using a special type of virus and at that moment we are able to control the position that is inserted into a chromosome
Give examples and the advantages of using genetically modified body cells
-Cystic fibrosis. Gene therapy allows gene added to produce therapeutic protein which reduces symptoms
-advantages of longer lasting treatment, reduced need for regular medication
Give examples and advantages of genetically modified stem cells
-GM bone marrow cells could create red blood cells that carry haemoglobin proteins with shape that can better transport oxygen preventing sickle cell anaemia
