genetic engineering

Question 1

what are the principles of genetic engineering

Answer 1

1. if the locus is known remove the required gene from a DNA molecule using a specific restriction enzymes to ensure the DNA molecule is cut it the right place
2. if the locus of the gene isn’t known use mRNA and reverse transcriptase to make the gene
3. splice the gene into the vector, e.g plasmid, using ligase to join the sticky ends of the gene and plasmid together using complimentary base pairings
4. the plasmid with the new gene is now integrated into the host cell and is called recombinant DNA
5. the host cell will then reproduce , if bacteria then by binary fission , and makes the protein
6. protein is then extracted

Question 2

why is bacteria commonly used

Answer 2

• it is prokaryote so does not have a nucleus so it is easier to incorporate the DNA
• they reproduce rapidly

Question 3

example of vectors

Answer 3

1. plasmids - carries the gene from a different species into a bacteria cell
2. viruses - DNA is taken out of the virus and replaced with the desired gene so when it infects a host cell it inserts the desired gene
3. DNA gun - coat a tiny gold pellet with multiple copies of a gene then fire it into the plant cells as some of the genes will remain attached to the pellet and will now be inside the plant cell

Question 4

how do genetic markers help identify which cells have taken up the new gene

Answer 4

• the plasmid used as a vector will have a genetic marker which is a gene that is antibiotic resistant
• so the cells which have taken up the new gene will survive while being grown on a medium containing bacteria as it will now contain the genetic marker which is antibiotic resistant

Question 5

concerns about genetic modification

Answer 5

1. health
2. people want the choice
3. environmental issues like increased chemical use in crops

Question 6

benefits of genetically modified organisms

Answer 6

1, crops can be modified to give higher yields and contain more nutrients
2. crops can be modified to have pest resistance
3. human proteins needed to treat various disorders can be produced by GM organisms
4. producing drugs using GM plants and animals would be cheaper than other methods once the process has been set up