P2 5c genetic modification

Question 1

what is genetic engineering?

Answer 1

the modification of genes in plants

- either by removal or insertion

Question 2

what are the advantages of genetic modification?

Answer 2

• increase the growth speed
• resistance to pests
• added minerals and vitamins that can help low income countries
• makes crop have a longer shelf life (less waste)
• cosmetic reasons

Question 3

what are the disadvantages of genetic modification?

Answer 3

• allergies can be trigged in some people

- the toxins from the disease resistance plants can make consumers resistant to it.

Question 4

how does genetic modification happen?

Answer 4

• a foreign gene is taken out of the genome by an enzyme (restriction enzymes)
• the DNA is cut at an angle (overhanging section on either side) this means some bases are exposed
• they then want to find a partner to match, they are called sticky ends
• a virus is used as a vector (without the infection part) that will inject the gene into the organism
• the organism will read the DNA and then it will make the protein etc

Question 5

what is transgenics?

Answer 5

when an organism has a foreign gene inserted into its genome it is a called transgenic organism

Question 6

what is the enzyme that cuts DNA?

Answer 6

restriction enzymes

Question 7

what happens to some of the bases when the gene is cut?

Answer 7

they become sticky ends that want to find another partner that they match to

Question 8

how do you genetically modify bacteria to produce human insulin?

Answer 8

• the gene for insulin production is located within a human chromosome
• restriction enzymes are used to isolate or cut out the human insulin gene, leaving it with sticky ends
• a bacterial plasmid is cut by the same restriction enzyme leaving it with corresponding sticky ends
• the plasmid and the isolated human insulin gene are joined together by DNA ligase enzyme
• its then inserted into a bacterial cell
• when the bacteria reproduce the plasmids are copied, they will all express the human insulin gene and make the protein

Question 9

why are bacteria useful for genetic engineering purposes?

Answer 9

• contain the same genetic code as the organisms we are taking genes from, so they can read it and produce the same proteins
• no ethical concerns over their manipulation and growth
• presence of plasmids separate from the main bacterial chromosome makes them easy to remove and manipulate

Question 10

what are the advantages of GM crops?

Answer 10

• reduced use of chemicals
• better for the environment
• cheaper
• increased yields from crops, as they are not competing with weeds

Question 11

what are the disadvantages of GM crops?

Answer 11

• increased costs of seeds, so smaller poorer farmers can’t compete
• increased dependency on certain chemicals
• risk of inserted genes being transferred to wild plants by pollinations, reducing usefulness (eg if weeds gain the gene)
• reduced biodiversity
• plants may not grow as well