Genetic engineering is a gene manipulation technique that modifies an organism's genetic material to produce new gene combinations. (p.280)
Genetically modified organisms (GMOs) contain recombinant DNA; an organism that contains recombinant DNA is called a transgenic organism. (p.280)
A genome is the complete set of DNA of an organism. (p.280)
Genetically modified food (GMF) includes crops such as paddy, oil palm, pineapple, corn and soya bean, and livestock such as salmon, cattle and goat. (p.281)
Advantages of GMF: overcome food shortage, reduce production cost, increase nutritional value, reduce pests and pesticide use, and increase food availability. (p.281)
Disadvantages of GMF: may endanger natural species, may transfer foreign genes to humans, and may have unknown effects on human health. (p.281)
Bacillus thuringiensis (Bt) genes inserted into corn and cotton make them resistant to insect pests. (p.281)
Super Salmon contains a growth hormone gene from Chinook salmon and grows faster. (p.282)
A frost-tolerance gene from Arabidopsis sp. was inserted into potato to allow growth in cold climates. (p.282)
Escherichia coli can be used to synthesise human insulin for patients with diabetes mellitus. (p.282)
Insulin production steps: cut the human insulin gene with restriction enzymes; insert it into a plasmid cloning vector; introduce the recombinant plasmid into a bacterium; the bacterial clone multiplies and produces insulin; then extract and purify insulin. (p.283)
A plasmid is a circular DNA found in bacteria and used as a cloning vector. (p.283)
13.2 Biotechnology
Biotechnology uses technology or methods to manipulate organisms to produce biological products. (p.284)
Biotechnology activities are classified by colour code, including green (agriculture), white (industrial), yellow (environmental and food), and blue (marine) biotechnology. (p.284)
Gene therapy replaces an abnormal gene with a normal gene, often delivered by a virus; it is used for diseases such as cystic fibrosis and muscular dystrophy. (p.285)
The first successful gene therapy was performed in 1990 on a patient with ADA-SCID. (p.285)
CRISPR is a technology that edits the genome during gene therapy. (p.286)
DNA profiling identifies individuals from unique DNA in blood, semen or skin; it is used to identify criminals, genetic diseases, paternity and maternity disputes, and organ donor suitability. (p.286)
DNA profiling was invented by Sir Alec Jeffreys in 1985. (p.286)
DNA profiling steps: extract DNA, cut with restriction enzymes, separate fragments by gel electrophoresis, transfer to nylon membrane, add radioactive probes, expose X-ray film to reveal the DNA profile. (p.287)
Bt crops such as Bt cotton, Bt corn and Bt brinjal produce toxins that kill pests, reducing pesticide use and increasing yield. (p.287)
Bioremediation uses bacteria to clean environmental pollutants; Alcanivorax borkumensis is used to treat oil spills. (p.288)
Dolly was the first cloned sheep. (p.288)
Biotechnology contributes to agriculture (improved crops and livestock), medicine (treatment of inherited diseases and infertility), forensics (identifying criminals) and the environment (decomposing waste). (p.289)