gene technology and ethics

Question 1

uses of GM microorganisms

Answer 1

• substances produced e.g. insulin and vaccines
• they store living record of DNA of another organism in DNA libraries ( DNA sequencing projects like HGP enable collection of sequenced DNA fragments to be stored and propagated in microorganisms through genetic engineering. these libraries are source of DNA fragments for further genetic engineering applications/further study)
• developing medical treatments and industrial processes
• GM pathogens arent used for obvious health reasons
• in the few cases they are used, it is for purposes of medical and epidemiological research
• concern that GM pathogens used for biological warfare (attempts to modify genomes of pathogens to be more virulent or resistant is unethical and largely prohibited except in specialised military research facilities

Question 2

ethical concerns for GM microorganisms

Answer 2

• initially, people uncomfortable with inserting human genes into microorganisms but pure human medicines, antibiotics and enzymes produced are overwhelmingly beneficial
• so relatively little ethical debate about use of GM microorganisms except for manipulation of pathogens in biological warfare

Question 3

insect resistance in GM soya beans

Answer 3

• scientists have inserted gene into soya beans so that they produce Bt protein
• Bt protein toxic to many pest insects that attack it and widely used as pesticide by organic farmers
• so farmers can spray to get rid of weeds
• making every other resource available to plants without using pesticides
• so farmers can grow much higher yield crop of soya beans with less labour and expense

Question 4

pros and cons of pest resistance in GM crops

Answer 4

• reduce amount of pesticide spraying, protecting the environment and helping poor farmers
• increased yield
• but non-pest insects and insect-eating predators might be damaged by toxins in GM plants
• insect pests may become resistant to pesticides in GM crops

Question 5

pros and cons of disease resistance in GM crops

Answer 5

• crop varieties resistant to common plant diseases can be produced, reducing crop losses and increasing yield
• but transferred genes might spread to wild populations and cause problems e.g. superweeds

Question 6

pros and cons of herbicide resistance in GM crops

Answer 6

• herbicides can be used to reduce competing weeds and increase yield
• but biodiversity could be reduced if herbicides are overused to destroy weeds
• and fear of superweeds

Question 7

pros and cons of extended shelf-life in GM crops

Answer 7

• reduces food waste
• but may reduce commercial value and demand for the crop

Question 8

pros and cons of nutritional value in GM crops

Answer 8

• nutritional value can be increased e.g. enhanced levels of vitamins
• but people may be allergic to different proteins made in GM crops

Question 9

pros and cons of growing conditions in GM crops

Answer 9

• crops can grow in wider range of conditions/survive adverse conditions e.g. flood/drought resistance
• no cons

Question 10

pros and cons of medical uses in GM crops

Answer 10

• plants could be used to produce human medicines and vaccines
• no cons

Question 11

major concerns about GM crops

Answer 11

• people in less economically developed countries will be prevented from using them by patents and issues of tech transfer
• when someone invents something, they can apply legal patent so no one else can use it without payment
• the people who most need the benefits of e.g. drought/flood resistant, high yield, added nutritional valued crops are therefore unable to afford the GM seed and also rely on harvesting seed from one year to plant the next which patenting makes impossible
• e.g. company that developed herbicide resistant and pesticide producing soya beans have patented them so farmers can buy beans to grow only in the year they are bought
• e.g. some organisations like IRRI developed engineered rice specifically to support farmers in less economically developed countries without patent constraints

Question 12

GM animals

Answer 12

• much harder to produce GM vertebrates especially mammals
• but scientists are researching use of microinjections (tiny particles of gold covered in DNA)
• and modified viruses to carry news genes into animal DNA
• to transfer disease resistance from one animal to another or modify physiology in farmed animals
• e.g. swine fever resistant pigs and faster-growing salmon

Question 13

pharming

Answer 13

• genetic engineering to produce human medicines
• creating animal models by adding or removing genes so that they develop certain diseases, acting as models for development of new therapies
• creating human proteins

Question 14

how does pharming create human proteins

Answer 14

• introduction of human gene coding for medically required protein
• animals sometimes used because bacteria cant produce all the complex proteins made by eukaryotic cells
• human gene can be introduced into genetic material of fertilised cow, sheep, goat egg along with promoter sequence so gene is expressed only in the mammary glands
• the fertilised transgenic female embryo is returned to the mother
• transgenic animal is born and when it matures and gives birth, it produces milk which contains the desired human protein to be harvested

Question 15

ethical issues with pharming

Answer 15

• should animals be genetically engineered to act as models of human disease
• is it right to put human genes in animals
• is it acceptable to put genes from another species into an animal without being certain it will not cause harm
• does genetically modifying animals reduce them to commodities
• is welfare compromised during the production of genetically engineered animals

Question 16

gene therapy in humans

Answer 16

• some human diseases e.g. CF and SCIDS are result of faulty mutant genes
• different ways of replacing the mutant allele with a healthy one involve removing desired alleles from healthy cells or synthesise healthy alleles in lab
• somatic cell gene therapy and germ line cell gene therapy

Question 17

somatic cell gene therapy

Answer 17

• involves replacing mutant allele with healthy allele in affected somatic cells
• often use viral vectors
• successful in treating retinal disease, immune diseases, leukaemia, myelomas, haemophilia

Question 18

disadvantages of somatic cell gene therapy

Answer 18

• only temporary solution for the treated individual
• healthy allele will be passed on every time a cell divides by mitosis but somatic cells have a limited life and are replaced from stem cells which still have the faulty allele
• so treated individual will pass on faulty allele to offspring

Question 19

problems with somatic cell gene therapy

Answer 19

• problems getting healthy alleles into affected cells, getting engineered plasmids into nucleus of cells and starting/maintaining expression of healthy allele

Question 20

germ line cell gene therapy

Answer 20

• alternative of treating somatic cells of people already affected by the disease
• inserts healthy allele into germ cells (usually eggs) or into embryo immediately after fertilisation (IVF)
• individual would be healthy with the normal allele in place and pass it onto their offspring
• successful with animal embryos

Question 21

problems with germ line cell gene therapy

Answer 21

• illegal for human embryos in most countries due to various ethical/medical concerns
• potential impact on the individual of an intervention on the germ cells is unknown
• human rights of unborn individual could be violated as it is done without consent and process is irrevocable once done
• tech may eventually be used to enable people to choose desirable or cosmetic characteristics of their offspring