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Unlock This CourseTransgenic organisms are living things that have had genes from other species inserted into their DNA. This amazing technology allows scientists to give organisms new abilities they never had before - like bacteria that can produce human insulin, or crops that resist diseases. It's like giving organisms superpowers by borrowing useful genes from other living things!
Key Definitions:
Scientists use special enzymes called restriction enzymes to cut DNA at specific points. They then insert the desired gene into the target organism's DNA using vectors like plasmids. The modified organism can then produce the new protein coded by the inserted gene.
Bacteria are the easiest organisms to genetically modify because they're simple and reproduce quickly. Scientists often use bacteria as living factories to produce useful substances.
To create transgenic bacteria, scientists follow these key steps: First, they identify and isolate the gene they want to transfer. Then they insert this gene into a plasmid (a small circular piece of DNA). The plasmid acts like a delivery vehicle, carrying the new gene into the bacterial cell. Once inside, the bacteria can produce the protein coded by the new gene.
Scientists extract the desired gene using restriction enzymes that cut DNA like molecular scissors.
A plasmid vector is cut open and prepared to receive the new gene.
The modified plasmid is introduced into bacterial cells, creating transgenic bacteria.
Before genetic modification, diabetics relied on insulin extracted from pig and cow pancreases. Now, transgenic bacteria containing the human insulin gene produce unlimited amounts of pure human insulin. This breakthrough has made diabetes treatment safer and more effective for millions of people worldwide.
Plant genetic modification has revolutionised agriculture by creating crops with improved characteristics. These GM plants can resist pests, tolerate herbicides, or have enhanced nutritional content.
There are several ways to create transgenic plants. The most common method uses a bacterium called Agrobacterium tumefaciens, which naturally transfers genes into plant cells. Scientists modify this bacterium to carry the desired genes instead of its own.
This natural gene transfer system is modified to deliver useful genes into plant cells. The bacterium infects the plant and transfers the new DNA into the plant's genome.
Bt corn contains genes from bacteria that produce toxins harmful to insect pests but safe for humans.
Roundup Ready crops can survive herbicide treatment, allowing farmers to control weeds more effectively.
Golden Rice contains genes that produce beta-carotene, helping prevent vitamin A deficiency.
Creating transgenic animals is more complex than modifying bacteria or plants, but it offers exciting possibilities for medicine and research.
Transgenic animals serve as living models for human diseases, helping scientists understand conditions like cancer, diabetes and Alzheimer's disease. Some transgenic animals can even produce human proteins in their milk or blood.
Scientists have created transgenic goats that produce spider silk proteins in their milk. Spider silk is stronger than steel and could be used to make bulletproof vests, surgical sutures and biodegradable fishing lines. This shows how genetic modification can create entirely new materials.
Genetic modification technology offers numerous benefits across different fields, from medicine to agriculture to environmental protection.
Production of human proteins like insulin, growth hormone and clotting factors. Gene therapy treatments for genetic diseases.
Increased crop yields, reduced pesticide use, enhanced nutritional content and crops adapted to harsh climates.
Bacteria that clean up oil spills, plants that remove heavy metals from soil and reduced chemical pesticide use.
While genetic modification offers many benefits, it also raises important concerns that scientists and society must carefully consider.
Some people worry about the safety of GM foods, though extensive testing has shown them to be safe. Environmental concerns include the possibility of GM genes spreading to wild plants or affecting non-target organisms. There are also economic concerns about farmers becoming dependent on GM seed companies.
All GM products undergo rigorous safety testing before approval. Regulatory agencies carefully evaluate potential risks to human health and the environment.
Genetic modification raises questions about whether humans should alter other living things. Some people have religious or philosophical objections, while others worry about the concentration of power in biotechnology companies. These debates help ensure that genetic modification technology is used responsibly.
Scientists have created transgenic mosquitoes that cannot transmit malaria or dengue fever. While this could save millions of lives, it raises questions about releasing GM organisms into the wild and the potential ecological consequences. Field trials are carefully monitored to ensure safety.
New technologies like CRISPR gene editing are making genetic modification faster, cheaper and more precise. This could lead to treatments for previously incurable diseases and solutions to global challenges like climate change and food security.
CRISPR-Cas9 allows scientists to edit genes with unprecedented precision, opening up new possibilities for treating genetic diseases and improving crops.