Scientists have developed techniques for artificial manipulation of DNA, cells and organisms
Understandings:
PCR can be used to amplify small amounts of DNA
Gel electrophoresis is used to separate proteins or fragments of DNA according to size
DNA profiling involves comparison of DNA
Genetic modification is carried out by gene transfer between species
Clones are groups of genetically identical organisms, derived from a single original parent cell
Many plant species and some animal species have natural methods of cloning
Animals can be cloned at the embryo stage by breaking up the embryo into more than one group of cells
Methods have been developed for cloning adult animals using differentiated cells
Applications:
Use of DNA profiling in paternity and forensic investigations
Gene transfer to bacteria using plasmids makes use of restriction endonucleases and DNA ligase
Assessment of the potential risks and benefits associated with genetic modification of crops
Production of cloned embryos produced by somatic cell nuclear transfer
Skills:
Design of an experiment to assess one factor affecting the rooting of stem cuttings
Analysis of examples of DNA profiles
Analysis of data on risks to monarch butterflies of Bt crops
Nature of science:
Assessing risks associated with scientific research—scientists attempt to assess the risks associated with genetically modified crops or livestock. (4.8)
Theory of knowledge:
The use of DNA for securing convictions in legal cases is well established, yet even universally accepted theories are overturned in the light of new evidence in science. What criteria are necessary for assessing the reliability of evidence?