IBDP>CORE TOPICS>TOPIC 4 GENETICS> TOPIC 4.4 GENETIC ENGINEERING AND BIOTECHNOLOGY
Outline DNA profiling (genetic fingerprinting), including one way in which it has been used. 5
DNA profiling: [4 max] sample of DNA / blood / saliva / semen is obtained;reference samples of DNA are obtained; PCR used to amplify / produce more copies of the DNA; DNA broken into fragments by restriction enzymes; DNA fragments are separated by gel electrophoresis; DNA separated into a series of bands;bands compared between different DNA samples; if pattern of bands is the same then DNA is (almost certainly) from same source; if some bands are similar then individuals are (almost certainly) related; specific example: [1 max] testing of paternity / forensics / classification / archeology / another specific example
Outline the use of restriction enzymes (endonucleases) and DNA ligase in gene technology. 6
restriction enzyme: bacteria/E. coli has plasmids; plasmids/DNA cleaved/cut by enzyme;at specific points; leaving sticky ends; other species DNA cleaved/cut out by enzyme at same base sequence; suitable example;ligase: DNA added to plasmid/other DNA; spliced to plasmid/other DNA by enzyme;at sticky ends; recombinant plasmids/DNA inserted into (new) host cells; (new) host cells may be cloned; Award [4 max] if only restriction enzyme or ligase aspects addressed
Discuss the potential benefits and possible harmful effects of genetic modification. 7
named example of desired outcome e.g. herbicide resistance; Award [6 max] if no named example given. Award [5 max] if both possible benefitsand possible harmful effects are not addressed.
Possible benefits: [4 max] benefits include more specific (less random) breeding than with traditional methods; faster than traditional methods; some characteristics from other species are unlikely in the gene pool / selective breeding cannot produce desired phenotype; increased productivity of food production / less land required for production; less use of chemicals (e.g. pesticides);food production possible in extreme conditions; less expensive drug preparation;e.g. pharmaceuticals in milk; human insulin engineered so no allergic reactions;may cure genetic diseases;
Possible harmful effects: [4 max]some gene transfers are regarded as potentially harmful to organism (especially animals);release of genetically engineered organisms in the environment;can spread and compete with the naturally occurring varieties;some of the engineered genes could also cross species barriers; technological solution when less invasive methods may bring similar benefits; reduces genetic variation/biodiversity
Possible benefits: [4 max] benefits include more specific (less random) breeding than with traditional methods; faster than traditional methods; some characteristics from other species are unlikely in the gene pool / selective breeding cannot produce desired phenotype; increased productivity of food production / less land required for production; less use of chemicals (e.g. pesticides);food production possible in extreme conditions; less expensive drug preparation;e.g. pharmaceuticals in milk; human insulin engineered so no allergic reactions;may cure genetic diseases;
Possible harmful effects: [4 max]some gene transfers are regarded as potentially harmful to organism (especially animals);release of genetically engineered organisms in the environment;can spread and compete with the naturally occurring varieties;some of the engineered genes could also cross species barriers; technological solution when less invasive methods may bring similar benefits; reduces genetic variation/biodiversity