Genetics 3.5 Genetic Modification & Biotechnology Flashcards
Outline the process of polymerase chain reaction (PCR)?
- DNA is collected and heated to a very high temperature to break the hydrogen bonds between the double stranded DNA.
- When the mixture is then slightly cooled, DNA primers are inserted using DNA complementary base pairing rules that form hydrogen bonds.
- When the mixture heats up again, Taq polymerase i added to create a new complementary strand of DNA using free DNA nucleotides and the base pairing rules
- This process repeats several dozen times so that millions of copies are produced
- copies are called tandem repeats
What is the process of PCR (artificial DNA replication) called?
Amplification
During PCR, are small or larger amounts of DNA used?
Only minute/very small amount of DNA is needed to amplify.
What is used to separate proteins or fragments of DNA?
Gel electrophoresis is used to separate proteins or fragments of DNA according to size.
What is used for DNA profiling?
Amplification/PCR, restriction enzymes to cut the DNA, gel electrophoresis to separate the DNA fragments.
How does gel electrophoresis separate proteins or DNA fragments?
When DNA is in fragments, they can be placed into the gel.
An electric field is applied which makes the molecules move to their opposite charge. The smallest fragments travel furthest towards positive charge.
UV probe is used to make them visible.
What are the uses for DNA profiling?
Solving crimes, Identifying paternity & analyzing evolutionary relationships.
What is GMO?
Genetically modified organisms where gene transfer between specifies has been carried out.
What is an example of a technique used for gene transfer to bacteria?
Production of Human Insulin
Step 1: Bacteria has plasmids that contain a small ring of naked DNA that can be copied and shared with other bacteria in order to share useful genes
Step 2: Restriction enzymes are used to cut the plasmid DNA.
Step 3: The gene for human insulin is inserted into the Plasmid. The sticky ends of the gene and the plasmid have to be complementary. DNA ligase sticks them together. The plasmid has now a recombinant DNA.
Step 4: The plasmid is inserted back into the bacteria where it acts as a vector.
Step 5: Under a suitable environment, the bacteria will quickly reproduce and be able to synthesize protein for human insulin due to the recombinant DNA.
Outline 2 examples of current uses of GMOs
Golden Rice: Was enriched with Vitamin A which helps improve the health of poor rural communities whose diet is dependent on rice but lack Vitamin A levels.
However, may go against religious, cultural heritage and beliefs because the food is no longer pure.
Poor communities may become dependent on the golden rice and not focus on a general improvement in their diet.
Bt corn: Bt corn has increased resistance to attack from insects, farmers need to use less insecticide. This reduces the cost of farming as well as environmental contamination
Bt corn plants have been genetically engineered to produce a toxic chemical that kills insects. This chemical is also present in the harvested crop. This may pose a threat to human health
Discuss potential benefits and possible harmful effects of genetic modification
MUST have examples:
Benefits:
• 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 chemical (e.g. pesticides in Bt Corn)
• food production possible in extreme conditions (Amflora - GM potatoes are cold/drought resistant)
• less expensive drug preparation e.g. pharmaceuticals in milk
• human insulin engineered so no allergic reactions
• may cure genetic diseases
Risks:
• Could have currently unknown harmful effects (e.g. toxin may cause allergic reactions in a percentage of the population)
• Accidental release of transgenic organism into the environment may result in competition with native plant species
• Possibility of cross pollination (if gene crosses the species barrier and is introduced to weeds, may have a hard time controlling weed growth)
• Reduces genetic variation / biodiversity (corn borer may play a crucial role in local ecosystem)
What are clones?
Clones are a group of genetically identical organisms or a group of cells derived from a single parent cell
Does cloning only occur artificially?
No. Cloning can occur naturally for some animal species and many plants such as potatoes, garlic, onions and wild strawberries.
Outline 2 techniques for cloning
Cloning at embryo stage:
Animals can be cloned at the embryo stage by breaking up the embryo into more than one group of cells
Cloning at adult stage:
using somatic-cell which are differentiated cell transfer
Outline the technique to clone adult animals
- Remove a somatic cell (usually a skin cell) from the mouse that you want to clone.
Obtain an egg cell from another organism - Remove the nucleus from the egg cell using a harp pipette. The egg now contains no DNA which makes it enucleated
- Remove the nucleus from the somatic cell using a sharp pipette
- The nucleus from the somatic cell is injected into the enucleated egg cell
- The cloned cell is treated with chemicals in order to stimulate it to begin cell division which makes a cloned embryo
- Implant the cloned embryo into the uterus of a surrogate organism. Once pregnancy is completed, the surrogate will give birth to the cloned organism
