3.5 Genetic modification & biotechnology

Gel electrophoresis Used to separate fragments of DNA or proteins according to size (uses an electric field to separate charge molecules) DNA is all negatively charged so everything moves in the same direction. Small fragments move faster, so in a given time they will move a greater distance.

PCR Used to copy a small DNA sample. PCR is rarely used to copy the entire genome – usually specific sequences are identified and copied. Detail is in topic 2.7.

DNA profiling Comparing samples of DNA Samples are collected and then broken into fragments using specific enzymes (restriction endonucleases) before being separated using gel electrophoresis. This produces a banding pattern unique to an individual.

Genetic modification Gene transfer between species Examples include: Production of human insulin using E. coli GM crops Goats that produce spider silk proteins in their milk

Cloning Clones are groups of genetically identical organisms with one parent. Follow this link and complete the activity

Investigating factors which affect rooting of stem cuttings Choose one of the following to investigate: Whether the stem is cut above or below the node Length of cutting Whether the end of the stem is left in the air to callus over night How many leaves are on the cutting Whether the cutting is placed in compost or water Temperature of the environment surrounding the cutting Whether a plastic bag is covering the cutting If there are holes in the plastic bag over the cutting

Techniques -Gel electrophoresis & DNA amplification (PCR), DNA profiling (inc. application for paternity/forensic testing) -Gene modification (one ex. Must be production of human insulin) -Transgenic plants (possible ex. Inc. herbicide resistant plants, salt tolerant tomato plants, Synthesis of beta-carotene (vitamin A precursor) in rice etc.) -Cloning (ex. Dolly) Discussions – must be balanced! -Ethical issues surrounding gel electrophoresis/PCR? Regulation? DNA data bases? Privacy? Ethical issues of DNA profiling? Can genetics determine behaviour…? -Ethical issues? - genetic modification/transgenic plants (ex. GM crops/designer babies) Consequences of introducing ‘new’ organisms into a ‘natural’ environment/cross breeding/does introducing a new species affect the existing ecosystem? If so how? -Ethical issues?- cloning Future? -Do you think there is a future for genetic modifications/biotechnology? -Any form of scientific research always involves risks, in term of genetic modification/biotechnology is it possible to assess/control these risk and are the risks worth the reward?

WARNING! This game (above) is very silly but quite fun and a nice way to go through gene therapy….