Evolution + Genetic Engineering

• The mechanism of evolution is that when too many offspring are produced, this leads to competition. Individuals that are best adapted to the environment survive and reproduce.
• Palaeontology is evidence of evolution.
• Fossils can be dated using radioactive carbon.
• A fossil is the remains of an organism.
• Sexual reproduction causes variation. This is because the genetic material of the gametes is different.
• Inherited variations are differences within a species that are controlled by genes e.g hair color.
• Acquired variations are differences within a species that develop over the life of the organism e.g an accent.
• A mutation is a change in the structure or amount of DNA in an organism e.g. cystic fibrosis.
• Mutagens are agents that change the DNA in a cell e.g. cigarette smoke.
• Evolution is the changes between members of a species over time.
• Natural selection is the mechanism by which members of a species with traits that allow them to survive in their environment, reproduce and pass these traits onto the next generation.
• Genetic engineering is the alteration and manipulation of genes.
• The six steps in genetic engineering are isolating, cutting, ligation, transforming, cloning, and expression.
• In isolation, a copy of the target gene is isolated from human cells.
• In cutting, the gene is cut out of the chromosome using a restriction enzyme. A plasmid is used as a vector and is also cut by the restriction enzyme.
• In ligation, the DNA that has been cut and the plasmid are joined with a ligase.
• In transformation, the plasmid is inserted into a bacterial cell which is transformed.
• In cloning, the bacterial cells are cloned and large numbers of the cell are produced.
• In expression, the bacterial cells express the gene.
• GMO stands for genetically modified organism.
• Genetic engineering is used to make insulin and growth hormones.