Genetic modification Notes

What Is Genetic Modification?

1. Genetic modification is the deliberate alteration of an organism’s DNA where specific genes are added, removed, or changed.
2. The aim is to give the organism a new characteristic.
3. Organisms produced this way are called genetically modified organisms (abbreviated as GMOs).
4. The modification is inherited when the organism reproduces.

How Do Scientists Genetically Modify An Organism?

1. A specific gene is isolated
   1. The gene codes for a desired protein.
   2. Restriction enzymes cut the gene from donor DNA.
2. The gene is inserted into a vector
   1. A vector is a DNA carrier.
   2. Common vectors include plasmids and viruses.
   3. The gene and vector are cut with the same restriction enzyme to form complementary sticky ends.
3. The vector transfers the gene into a host cell
   1. The vector enters the host organism.
   2. The inserted gene becomes part of the host DNA.
4. The inserted gene is expressed
   1. The host cell transcribes and translates the gene.
   2. A new protein is produced.
   3. The protein causes a new characteristic.

How Are Bacteria Genetically Engineered?

1. The desired gene is isolated
   1. Restriction enzymes cut the gene from donor DNA.
   2. Sticky ends are formed on both sides.
2. A plasmid is removed from a bacterium
   1. The same restriction enzyme cuts the plasmid.
   2. Matching sticky ends are produced.
3. The gene is joined into the plasmid
   1. DNA ligase joins the gene and plasmid.
   2. A recombinant plasmid is formed.
4. The recombinant plasmid enters the bacterium
   1. This step is called transformation.
5. The bacteria reproduce
   1. Bacteria divide by binary fission.
   2. All daughter cells contain the inserted gene.
   3. Large quantities of the protein can be produced.

What Are The Uses Of Genetically Modified Organisms?

1. Production of human insulin
   1. GM bacteria produce insulin identical to human insulin.
   2. Used to treat diabetes.
2. Production of hormones
   1. Human growth hormone can be produced by GM organisms.
   2. Reduces reliance on animal or human donors.
3. Pest-resistant crops
   1. Crops contain genes that deter insect damage.
   2. Reduces need for chemical pesticides.
4. Improved nutritional content
   1. Crops can be modified to contain additional vitamins.
   2. Rice containing vitamin A (branded as "golden rice")

What Are The Benefits And Risks Of Genetic Modification?

1. Benefits
   1. Increased food production
      1. Higher crop yields.
      2. Improved nutritional value.
   2. Medical benefits
      1. Cheaper production of medicines.
      2. Large-scale protein synthesis.
2. Risks
   1. Environmental risks
      1. GM organisms may spread genes to wild populations.
      2. Ecosystems may be disrupted.
   2. Health concerns
      1. New allergens could be introduced.
   3. Ethical concerns
      1. Concerns about human interference with nature.

Why Has Genetic Modification Been Controversial?

1. Ethical concerns
   1. Some view genetic modification as unnatural.
   2. Animal welfare concerns exist in modified livestock.
2. Economic concerns
   1. GM seeds are often patented.
   2. Farmers may become dependent on large companies.
3. Social and security concerns
   1. Genetic technology could be misused.
   2. Unequal access may increase global inequality.