Genetic Modification: Changing DNA for a Better World

 

What is Genetic Modification?

• Genetic modification is like reprogramming an organism by changing its DNA.
• Scientists can remove, change, or insert genes to give an organism new traits, like pest resistance or the ability to make medicine.

 

Why is Genetic Modification Useful?

1. Medicine Production:
   • Human genes can be added to bacteria to make important proteins like insulin for diabetes treatment.
2. Better Crops:
   • Crops can be modified to:
     • Resist herbicides (weed killers).
     • Resist insect pests.
     • Improve nutrition, e.g., golden rice with extra vitamin A.

 

How Does Genetic Modification Work?

Example: Bacteria Producing Human Proteins

This involves six simple steps:

1. Isolating the Gene:

   • Use restriction enzymes (molecular scissors) to cut out the human DNA that codes for the desired protein.
   • This leaves sticky ends (overhanging DNA sequences).

2. Preparing the Bacterial Plasmid:

   • Plasmids are circular DNA in bacteria.
   • The same restriction enzymes are used to cut the plasmid, leaving matching sticky ends.

3. Combining DNA:

   • The human gene is inserted into the plasmid.
   • Use DNA ligase (a glue enzyme) to join the DNA pieces together.
   • This forms a recombinant plasmid (a plasmid with new DNA).

4. Inserting the Plasmid into Bacteria:

   • The recombinant plasmid is put back into the bacteria.

5. Multiplying the Bacteria:

   • The bacteria divide rapidly, creating millions of copies, all carrying the human gene.

6. Producing the Protein:

   • The bacteria use the inserted gene to make the desired protein, e.g., insulin.

 

Advantages and Disadvantages of Genetic Modification

Advantages	Disadvantages
Crops resist pests and diseases, reducing pesticide use.	Potential harm to non-target species (e.g., beneficial insects).
Higher yields and improved nutrition (e.g., golden rice).	Modified genes may spread to wild plants, causing ecological issues.
Reduces production costs for medicine and food.	Ethical concerns about altering natural organisms.
Crops can tolerate harsh conditions, like drought or salinity.	Risk of creating superweeds resistant to herbicides.