Topic 9 - Genetic Engineering Flashcards
what do restriction enzymes do?
recognise specific sequences of DNA and cut the DNA at these points
what do ligase enzymes do?
join two pieces of DNA together
what are two different bits of DNA stuck together known as?
recombinant DNA
what is a vector?
something used to transfer DNA into a cell
What are the two sorts of vectors?
plasmids and viruses
what are plasmids?
small, circular molecules of DNA that can be transferred between bacteria
what are viruses?
viruses insert DNA into organisms they infect
how does genetic engineering work?
the DNA you want to insert is cut out using a restriction enzyme. the vector DNA is then cut open using the same restriction enzyme.
the vector DNA and the DNA you’re inserting are mixed with ligase enzymes, joining the two to produce recombinant DNA. the recombinant DNA is inserted into other cells, who use the gene you inserted to make the protein you want.
what does transgenic mean?
something containing genes transferred from other species
how can crops be genetically modified to increase food production?
make them insect-resistant or herbicide-resistant
what are the positives of making crops insect-resistant?
farmers don’t have to spray as many pesticides, so wildlife that doesn’t eat the crop isn’t harmed
what are the positives of making crops herbicide-resistant?
farmers can spray their crops to kill weeds, without affecting the crop.
what are the concerns about growing genetically modified crops?
transplanted genes may get out into the environment - creating ‘superweeds’
affects on human health and food chains
