Genetic modification Revision Notes

Genetic modification is the process of changing an organism's genetic material (DNA) to alter its characteristics.

This can be done by adding new genes, changing existing genes, or removing certain genes from the organism's DNA.

These changes allow the organism to develop new traits or improve existing ones, which can be useful in various fields such as medicine and agriculture.

• Altering DNA changes the organism's traits.
• Modification can involve adding, changing, or removing genes.
• The goal is to produce new or improved characteristics.

Genes can be added from other organisms to introduce new traits.

Existing genes within the organism can be changed to modify how traits develop.

Removing specific genes can eliminate unwanted traits or functions.

• Adding genes introduces new characteristics.
• Changing genes alters gene function or expression.
• Removing genes can prevent certain traits.

Genetic modification helps create organisms with beneficial traits, such as disease resistance or improved productivity.

It supports advances in medicine, agriculture, and scientific research by enabling precise control over traits.

This technology differs from traditional breeding by directly altering DNA rather than selecting traits over generations.

• Creates beneficial traits efficiently.
• Supports medicine and agriculture.
• Directly changes DNA, not just traits.

Human genes can be added to bacteria so they produce human proteins, such as insulin, used in medicine.

This allows bacteria to manufacture proteins that they cannot naturally produce, aiding treatments for diseases like diabetes.

• Human genes inserted into bacteria.
• Bacteria produce human proteins for medical use.
• Example: insulin production.

Genes can be added to crops to make them resistant to herbicides, allowing farmers to kill weeds without harming the crop.

Other genes can make crops resistant to insect pests, reducing crop damage and pesticide use.

Genes can also be added to enhance the nutritional value of crops, such as increasing vitamin content to improve human health.

• Herbicide resistance protects crops during weed control.
• Insect pest resistance reduces crop damage and pesticide need.
• Enhanced nutrition improves dietary value of crops.

These genetic modifications improve crop yields and quality, making farming more efficient and sustainable.

Producing human proteins in bacteria provides a cost-effective way to manufacture medicines.

Enhancing nutrition in crops helps address dietary deficiencies worldwide.

• Improves agricultural productivity.
• Supports medical protein production.
• Enhances human nutrition through crops.

Scientists isolate the human gene that codes for the desired protein by cutting human DNA with restriction enzymes.

These enzymes cut DNA at specific sequences, creating sticky ends that help join DNA fragments later.

• Restriction enzymes cut human DNA.
• Sticky ends are created for joining DNA.
• Gene for the protein is isolated.

The bacterial plasmid DNA is cut with the same restriction enzymes to produce complementary sticky ends.

This allows the human gene to fit precisely into the plasmid DNA.

• Plasmid DNA cut with same enzymes.
• Complementary sticky ends formed.
• Prepares plasmid for gene insertion.

DNA ligase enzyme joins the human gene and plasmid DNA by forming bonds, creating a recombinant plasmid.

This recombinant plasmid contains DNA from both human and bacteria.

• DNA ligase joins DNA fragments.
• Recombinant plasmid is formed.
• Plasmid carries human gene.

Recombinant plasmids are introduced into bacteria by methods such as transformation (details not required).

Bacteria take up the plasmids and become genetically modified.

• Recombinant plasmids enter bacteria.
• Bacteria become genetically modified.
• Allows bacteria to carry human gene.

Bacteria multiply, copying the recombinant plasmid with the human gene.

As bacteria grow, they express the human gene and produce the human protein, which can be harvested for medical use.

• Bacteria reproduce and copy plasmids.
• Human protein is produced by bacteria.
• Protein can be collected for use.

Genetically modified (GM) crops have been engineered to possess traits that improve agricultural productivity and food security. For example, GM soya and maize can be resistant to pests and diseases, reducing the need for chemical pesticides. GM crops can also tolerate environmental stresses like drought, leading to higher yields. GM rice has been developed to contain added vitamins, such as vitamin A, to help combat malnutrition in developing countries.

• Pest and disease resistance reduces pesticide use.
• Tolerance to environmental stresses improves yields.
• Enhanced nutritional content addresses malnutrition.
• Examples include GM soya, maize, and vitamin-enriched rice.

Despite benefits, there are concerns about GM crops. The long-term health effects of consuming GM foods are not fully known. Cross-contamination between GM and non-GM crops can reduce biodiversity. Economic concerns include increased control of agriculture by large biotech companies, which may impact small-scale farmers' independence and costs.

• Unknown long-term health impacts of GM foods.
• Risk of cross-contamination affecting biodiversity.
• Economic control by biotech companies over farmers.
• Potential dependency on purchasing GM seeds.

Evaluating GM crops requires weighing their potential to improve food security and reduce chemical use against environmental, health, and economic risks. Ongoing research and regulation aim to maximize benefits while minimizing drawbacks. Understanding both sides helps make informed decisions about GM crop use.

• GM crops can improve food security and reduce pesticides.
• Risks include health, environmental, and economic concerns.
• Regulation and research are important for safe use.
• Informed decisions require understanding pros and cons.