genetic engineering

what is the basic idea of genetic engineering

moving useful genes from one organism's chromosomes into the cells of another

what is needed/ tools/ equipment in genetic engineering

- desired DNA

- vector (plasmids or virus) DNA

- restriction enzyme

- ligase enzymes

- cells that you want to insert the desirable gene into

- fermenter (SOMETIMES USED) to grow the new cells in huge numbers

what can vectors also be known as

carriers

role of restriction enzymes

RECOGNISE specific sequences of DNA + CUT the DNA at these points

role of ligase enzymes

JOIN pieces of DNA together

what is a vector/ role of a vector + what are the 2 types of vectors

- something used to TRANSFER DNA into a cell

- plasmids and viruses

what is recombinant DNA

the 2 different bits of DNA stuck together (DOESN’T HAVE TO BE FROM DIFF SPECIES)

what are plasmids

- small circular molecules of DNA found in bacteria

- that can be transferred between bacteria

(plasmid is essentially piece of DNA)

why can viruses be a vector

because they insert DNA into the organisms they infect

genetic engineering steps

- restriction enzyme cuts desired gene out of the DNA

- restriction enzyme cuts open vector DNA

- ligase enzyme joins the desired gene and vector DNA together (to produce recombinant DNA)

- the vector inserts the recombinant DNA into the cells

- a fermenter may be used to grow the cells in huge numbers

what happens once a cell has had the desired gene inserted into it

the cell can then use the gene inserted to make the protein you wanted

transgenic organism

one whose genome has been altered by the transfer of a gene or genes from another species or breed

process for making human insulin

- same process highlighted as above

- the desired gene = gene for human insulin

- this is taken from human DNA

- this is joined with plasmid DNA

- this recombinant DNA inserted into bacteria

- this bacteria then grown in huge numbers in a fermenter

what is this insulin then used for

people with diabetes

how can plants be genetically modified to improve food production

- resistance to insects

- resistant to herbicides (chemicals that kill plants)

2 positives of insect resistant crops

- less pesticides needed -> less wildlife harmed

- crop yield increased -> less damage/ crop death from insects eating at them

how can herbicide-resistance increase crop yield

- farmers can spray their crops to kill weeds, w/out affecting crop itself

- w/out the weeds, less competition for resources so improved food production

concerns about genetically modified crops (2)

- transplanted genes may get out into the environment e.g herbicide resistant gene creating "superweeds"

- affect food chains or human health (GM crops could outcompete the natural ones and affect the animals that eat those)