6.2.4 Genetic Engineering

Applications of Genetic Engineering

• In Plants: Engineered to enhance traits like disease resistance or to produce larger fruits.
• In Bacteria: Engineered to produce substances beneficial to humans, such as insulin for diabetes treatment.

The Process:

1. Gene Extraction: A desired gene is 'cut out' from an organism's DNA using restriction enzymes, creating sticky ends (unpaired bases).
2. Vector Preparation: A plasmid (circular DNA) or virus is cut with the same restriction enzyme, creating matching sticky ends. The plasmid also contains an antibiotic resistance marker.
3. Gene Insertion: The gene is inserted into the plasmid or virus, and the sticky ends are joined by DNA ligase enzymes.
4. Transformation: The recombinant plasmid or virus is introduced into a host cell (like bacteria). As the bacteria multiply, they replicate the modified gene. Antibiotic resistance helps identify successful modifications.

• In Plants: The modified gene is introduced into meristematic (unspecialised) cells, which can grow into fully modified plants.

Genetically Modified (GM) Crops

• Benefits: Engineered for insect resistance and herbicide tolerance, leading to higher yields and less crop loss.

Genetic Modification in Medicine

• Gene Therapy: The introduction of normal genes into a patient's cells to correct genetic disorders by producing the correct proteins.

Benefits and Risks of Genetic Engineering

Benefits	Risks
Medicine: Mass production of hormones (e.g., insulin) using microorganisms.	Environmental Impact: GM crops might affect wild plants and insects, potentially reducing biodiversity.
Agriculture: Enhanced yields by improving growth rates, enabling crops to grow in extreme conditions, and producing natural pesticides or herbicides.	Health Concerns: The long-term effects of GM crops on human health are not fully understood.
Nutritional Enhancement: Crops with added vitamins can be produced in areas where nutrients are scarce.	Ethical Concerns: Genetic engineering in agriculture might lead to human genetic modifications, raising concerns about designer babies.
World Hunger: Increased yields could help address food shortages as the global population grows.	Resistance: GM crops could create super weeds and pests due to increased resistance to herbicides and pesticides.