6.2b Genetic Flashcards
What is genetic engineering
Why is it accurate and quicker than selective?
The process of altering an organisms genome to produce an organism with desired characteristics, BY introducing a gene from ANOTHER ORGANISM to give it this desired characteristic
which is faster than selective breeding (takes many generations and is exact).
Accurate because single genes can be targeted and occur in ONE GENERATION.
How does it basically work, what I the key thing
By adding foreign genes into the plant or animal at EARKY STAGE OF DEVELOPMENT. as the organism grows it shows the characteristics desired
Key thing is early in development so cells can divide enough to produce.
Tomatoes become frost resistant by inserting antifreeze gene in the tomato found in fish
What are benefits of GE (3)
1) how are they more yield now
2) what is gold rice
3) medical
1) crops can be GM toproduce HIGHER
yields from same amount of land (intensive farming)
- can be resistant to pests (toxins produce, now less pesticide needed, this way they don’t make to higher food chain, other insect etc). Farmers use less pesticide and more yield now
-virus resistant
- herbicide resistant (now farmers can spray all plants knowing that only the weeds will die (not the ones they use themselves))
- finally gm can target genes that use water more efficiently for example and manipulate this too…
2) used in VITAMIN deficiency
- rice in parts of world don’t have vitamin A, and is main source of diet , gum to make more in rice. This vitamin needed for NIGHT VISION, and delayed growth . (Here gene taken from carrot that produces beta carotene, put into rice and human convert that into vitamin a) Also bt corn produce the toxins that kill pests (taken from bacillus Thuringia is that coded for protein of toxin, placed into corn maize)
3) BACTERIA, here medical drugs like insulin can be produced or others too like growth hormone
4) microbes that take in harmful gases , reduce the greenhouse effect
What are
Problems with GE (plants particularly here)
5 problems 1) unethical 2) health human 3) unforeseen consequences 4) cross polination 5 ) food chain
1) 1) if cross contamination happens and this new gene makes it way to another species, gene is in wild plants, (say it was a herbicide resistant gene, now all these weeds could potentially have it, disrupting an entire ecosystem and farmers work). So CROSS POLINATION= superweed
2) could potentially produce allergens causing allergies for humans (HEALTH PROBLEMS FOR HUMANS). People blame it for a rise in these
3) could disrupt FOOD CHAIN (things that produce toxins for insects could cause food chain disruption and smoke for a species)
- BIODIVERSITY ALSO GETS AFFECTED HERE ASWELL…
4) UNFORESEEN PROBLEMS, don’t yet understand long term effects of say bt gene in golden rice…
5) UNETHICAL - shouldn’t do it for human benefit (especially for animal sufferers)
- don’t want potential designer babies and poor people becoming genetic underclass in future
How are they genetically modified (insulin)
1) Insulin produce cell in human (DONOR CELL), has dna removed, its gene that’s coded for insulin identified . Now it is cut out using RESTRICTION EMZYMES
2) As enzymes are highly specific they cut at a specific location, Leaving certain ends called STICKY ENDS
3) next a plasmid is removed from a host organism Bacteria, and a section is also cut out using the SAME RESTRICTION EMZYME. This is essential as it then leave s the same sticky ends as the gene in question. These sticky ends are COMPLIMENTARY to each other too…
4) The foreign gene, human one, is inserted into the plasmid. Next LIGASE ENZYMES are used which rejoins the sticky ends= now recombinant (mixture) plasmid formed.
5) at this point a marker gene can be added too
6) Now plasmid , which is a VECTOR, is put back In the bacteria which is nOW TRANSGENIC .
7) let to grow (here they can divide and clone ), and then you can use antibiotic on it and select the ones that are survived, these the ones that successfully received the gene . These bacteria will now produce desired characteristic…
8) can then be industrially produced, where insulin is extracted, prudifed, and put in medicines…
How to check if successfully transferred?
1: insert an antibiotic resistant gene in the same vector that has Däne for desired characteristic
2) transfer bacteria to Agar plate THAT HAS THE ANTIBIOTICS IN IT, incubate and let the, grow and divide
3) only bacteria which have the antibiotic gene, and thus desired gene successfully will survive and duplicate others will die
Pimped into fermenter units, optimal conditions for growth, then heated so they die and leave insulin behind…
What are advantages and disadvantages for gym insulin production?
1) insulin produced for growing demand
- before insulin was used through log pancreases, so side Effects
2) now no human or less sideffects
3) cultures that haram can now use this
Disadvantages
- only works if bacteria have amino acids to make the proteins we are after.
How is GM done in plants too?
1) The donor plant has its dna removed and desired gene for characteristic identified. This is then count of the dna by restriction enzymes exposing sticky ends on the gene.
2) similarly the DNA of a virus (vector in this case, used as it infects the plant by inserting its genes INTO TO IT SO ALREADY USEFUL) is cut open using same restriction enzyme to reveal a section with same sticky ends as the gene.
3) Now the useful gene is inserted into the virus dna vector , joined by ligase, this is called insertion
4) Now this virus is allowed to infect the plat, inserting dit’s dna and thus desirable gene into the host plant dna.
5) This plant is now TRANSGENIC PLANT, and it grows to show the characteristic desired .
6) This plant can then be cloned using Auxin and scrapings of meristem which can then be grown to all be pest resistant say….
THIS IS HOW FARMERS INCREASE YIELD….
Summary quick
Why restriction used?
What is vector?
1) Dna removed from donor and gene identified, cut open using restriction enzyme, similarly this happens in vector of host (or not in plant), using same restriction enzyme
2) This means both has sticky ends, and now useful genes inserted du to space of vector dna. Joined by lipase
3) This vector then either placed into the bacteria , or infected into plant. You can use marker gene here too
4) let them grow, identify which ones have successfully taken the, in then clone and mass Produce
Restriction allows both to have same sticky ends which are complimentary to each other allowing them to successfully join in presence of ligase…
Vector is something used to transfer dna into a cell, often plasmids or viruses
