Applications of biotechnology: medicine, agriculture, gene therapy and stem cells
Biotechnology gives medicines like insulin and vaccines, and GM crops like Bt cotton. Gene therapy fixes faulty genes, and stem cells can repair tissues.
In medicine
| Product | Use |
|---|---|
| Human insulin | Treats diabetes |
| Human growth hormone | Treats dwarfism caused by too little growth hormone |
| Interferons | Proteins that help the body fight viral infections |
| Blood clotting factors | Treat haemophilia, a disorder in which blood does not clot properly |
| Recombinant vaccines | The hepatitis B vaccine is made by yeast carrying a virus gene; it is safe and gives protection |
| Diagnostic tests (ELISA, PCR) | Detect diseases such as HIV early |
In agriculture: genetically modified organisms
A genetically modified organism (GMO) is a plant, animal or microbe whose genes have been changed by genetic engineering. It is also called a transgenic organism. Bt cotton has a gene from the soil bacterium Bacillus thuringiensis. The gene makes a protein that kills bollworms, the pests that eat cotton bolls. So farmers need less insecticide. Golden rice makes beta-carotene, which the body turns into vitamin A. The Flavr Savr tomato ripens slowly and stays fresh longer. Transgenic animals exist too. Rosie, a cow (1997), gave milk with a human protein that is better for babies.
Benefits and concerns of GMOs
In India, GM crops must be tested and approved by the Genetic Engineering Appraisal Committee (GEAC) before farmers can use them.
Gene therapy
Gene therapy treats a genetic disease by putting a normal gene into a person's cells. The normal gene replaces or corrects the faulty one. A harmless virus is often used as the vector to carry the gene. The first gene therapy was given in 1990 to a four-year-old girl with ADA deficiency. This disorder weakens the immune system. Her white blood cells were given a working ADA gene and put back into her body. Somatic gene therapy changes body cells, so the change is not passed to children. Germline gene therapy changes eggs or sperms, so the change could pass to the next generation. Gene therapy is now used or tested for some cases of sickle cell anaemia and haemophilia.
Stem cells
Stem cells are unspecialised cells. They can divide many times and turn into special cells such as nerve, muscle or blood cells. Embryonic stem cells come from early embryos and can become any type of cell. Adult stem cells are found in bone marrow, skin and other tissues; they form a limited range of cells. Umbilical cord blood is also rich in stem cells and can be stored in a cord blood bank. Stem cell therapy uses them to repair damaged tissue. A bone marrow transplant for leukaemia (blood cancer) is one example.
Bt cotton is widely grown by Indian farmers. The hepatitis B vaccine given to babies is made by genetically engineered yeast.
2 marks: “What is gene therapy?” Treating a genetic disorder by putting a normal gene into a person's cells to replace or correct a faulty gene. It was first used in 1990 for ADA deficiency.
2 marks: “What are stem cells? Name their two types.” Unspecialised cells that can divide and form many cell types. Embryonic stem cells and adult stem cells.
7 marks: “Explain the applications of biotechnology in medicine and agriculture.” Medicine: insulin, growth hormone, interferons, recombinant vaccines, diagnosis. Agriculture: Bt cotton, golden rice, GM benefits and concerns. Gene therapy (ADA, 1990) and stem cells.
Biotech helps four ways: medicines, crops, mending genes (gene therapy) and making new cells (stem cells).