Biotechnology and Genetic Modification

The One Thing

Biotechnology uses living organisms, cells, or biological molecules to produce useful products and processes. Genetic modification is a more specific application that alters an organism’s DNA, often by inserting a desired gene from another organism, and its use must be assessed alongside health, environmental, ethical, and economic risks.

Reactions, Processes and Experiments

Key Terms

• Biotechnology: The use of living organisms, cells, or biological molecules to make useful products or carry out useful processes.
• Genetic modification: Changing an organism’s DNA by inserting, removing, or altering genes to produce a desired characteristic.
• Genetic engineering: A technique used to transfer a specific gene from one organism into another organism.
• Gene: A section of DNA that codes for a particular protein or characteristic.
• Recombinant DNA: DNA formed by joining genetic material from two different sources.
• Vector: A carrier used to transfer a gene into a host cell, such as a bacterial plasmid or a virus.
• Plasmid: A small circular DNA molecule found in bacteria that can be used as a vector in genetic engineering.
• Restriction enzyme: An enzyme that cuts DNA at a specific base sequence.
• Ligase: An enzyme that joins DNA fragments by forming bonds between them.
• Host cell: A cell that receives recombinant DNA and uses the inserted gene.
• Insulin production: A use of genetic engineering in which the human insulin gene is inserted into bacteria or yeast, which then produce insulin.
• Fermentation: The use of microorganisms under controlled conditions to produce useful substances such as bread, yoghurt, cheese, or biofuels.
• Fermenter: A vessel in which microorganisms or cells are grown under controlled conditions.
• Selective breeding: Choosing parents with desirable characteristics and breeding them to increase those characteristics in offspring.
• Clone: A genetically identical copy of a cell or organism.
• Tissue culture: The growth of cells, tissues, or small pieces of plants in sterile nutrient media.
• Transgenic organism: An organism that contains a gene transferred from another species.
• Genetically modified crop: A crop whose DNA has been changed to give it a useful characteristic, such as pest resistance or improved nutrition.
• Bioremediation: The use of organisms, especially microorganisms, to remove or break down pollutants.
• Aseptic technique: Methods used to prevent unwanted microorganisms from contaminating biological cultures.
• DNA: The molecule that contains genetic instructions.
• Gene expression: The use of information in a gene to make a protein.

Easily Confused

• Biotechnology and genetic modification: Biotechnology is the broad use of living systems and biological molecules; genetic modification specifically changes an organism’s DNA.
• Genetic engineering and selective breeding: Genetic engineering transfers a specific gene directly and rapidly, whereas selective breeding chooses parents with desired features and repeats breeding over generations.
• A gene and DNA: DNA contains genetic instructions, while a gene is a section of DNA coding for a particular protein or characteristic.
• A plasmid and a vector: A plasmid is a small circular DNA molecule in bacteria; a vector is any carrier used to transfer a gene, including a plasmid or a virus.
• Aerobic and anaerobic respiration in yeast: Aerobic respiration uses oxygen and produces carbon dioxide, water, and energy; anaerobic respiration produces ethanol, carbon dioxide, and less energy without oxygen.
• A clone and a transgenic organism: A clone is genetically identical to its source organism or cell; a transgenic organism contains a gene transferred from another species.
• Fermentation and a fermenter: Fermentation is the biological process using microorganisms to produce useful substances; a fermenter is the vessel in which the microorganisms are grown.
• Aseptic technique and fermentation: Aseptic technique prevents contamination, whereas fermentation uses microorganisms under controlled conditions to make products.

What Gets Asked

• Describe the sequence of genetic engineering: identify, isolate or copy, cut with restriction enzymes, join with ligase, insert into a host cell, and select cells containing the desired gene. Marks are lost by omitting the role of the enzymes or the selection stage.
• Explain why bacteria are used in genetic engineering: they reproduce rapidly, are relatively simple to grow, and can contain plasmids. Marks are lost by giving only one reason or failing to link bacteria to plasmid vectors.
• State the conditions controlled in a fermenter: temperature, pH, oxygen supply, nutrient concentration, and stirring. Sterile conditions are also required to prevent contamination.
• Compare aerobic and anaerobic respiration in yeast: use the equations exactly: glucose + oxygen → carbon dioxide + water + energy and glucose → ethanol + carbon dioxide + less energy. Marks are lost by confusing the products or omitting oxygen from the aerobic equation.
• Outline selective breeding: select parents with desired features, breed them, select the best offspring, and repeat for several generations. Marks are lost by describing genetic engineering instead.
• Evaluate genetically modified organisms: discuss benefits such as higher crop yields, reduced insecticide use, improved food quality, medicines, and treatment of inherited disorders, alongside risks including unintended health effects, gene transfer to wild relatives, reduced biodiversity, resistant pests or weeds, and ethical concerns.