5.2/3 Selective breeding + Genetic modification/genetic engineering Flashcards
(24 cards)
what is transgenic organism?
organisms which have received genes from another species
What are vectors?
vectors can be used to carry the DNA of one organism into another
Genetic engineering - what are the first 2 steps?
- human insulin gene must be located on the chromosome (11)
- gene is then cut from the rest of the chromosome using a special enzyme called a DNA restriction enzyme
What is the function of ligase enzymes?
DNA ligase enzyme forms bonds between the nucleotides
What is the plasmid carrying the human DNA referred to as?
a vector
Why is a fermenter and the nutrient medium and air entering the system sterilised prior to use?
to prevent the growth of pathogens or competing microorganisms
Why is transgenic bacteria placed into a fermenter?
in order to increase in number
What are the optimum conditions needed to produce human insulin?
providing oxygen via the air line - for respiration
stirring the mixture to prevent clumping and a shortage of nutrients
monitoring temperature and cooling the fermenter if needed - optimum temperature for enzymes
adding more nutrient medium
What happens once the insulin is secreted by the bacteria?
It is then collected from the fermenter, purified and distributed
What are the two main stages of genetic modification in plants?
introducing the new gene or genes into plant cells
producing whole plants from just a few cells (tissue culture)
What are the different traits that can be added to plants?
higher yield
ability to produce extra nutrients
resistance to extremes in weather
resistance to pests
resistance to disease/pathogens
What are the advantages of genetic modified plants?
more precise method than selective breeding
higher crop yield/better food quality
less pesticide/herbicide used so less pollution
disease resistant/pest resistant/herbicide resistant
What are the disadvantages of genetically modified plants?
not accepted by public
long term affects are unknown
may affect food chains or environment
reduces variation
What are the first steps to genetic modification in plants? (resistance against insect example)
insecticide gene created using recombinant DNA technology
plasmid vectors
What is ligase?
enzymes which join pieces of DNA together
What is restriction enzymes?
Enzymes which cut DNA at specific sites
What is the definition of genetic engineering?
the transfer of genetic material from one species to a different species
Why is transgenic bacteria placed into a fermenter?
to increase in number
Genetic engineering - what are the 3rd and 4th steps?
- A plasmid is removed from the bacterium (E. coil) and cut open with the same DNA restriction enzyme
- Each DNA restriction enzyme cuts at a specific sequence of bases, producing short single stranded sections called sticky ends
Genetic engineering - what is the 5th steps?
- The human insulin gene and plasmid join together due to complementary base pairing at the sticky ends.
Genetic engineering - what is the 6th steps?
- A DNA ligase enzyme forms bonds between the nucleotides to make this a single piece of DNA.
What is the plasmid called at the ed of genetic engineering?
We say the plasmid is now recombinant DNA - it is a combination from two different sources.
What are the middle steps to genetic modification in plants? (resistance against insect example)
digestion with restriction enzymes
cleaved DNA - cleaved vectors
growing plant cells take up insecticide gene from plasmid vectors
What are the last steps to genetic modification in plants? (resistance against insect example)
select for insecticidal cells
cell used for plant propagation
insects that feed on the plants will die
