Genetic Modification Flashcards
All 19 cards in this deck
What is selective breeding?
Choosing parents with a desired characteristic and breeding them together, repeating over many generations so the characteristic becomes more common.
Give two characteristics that food plants and domesticated animals are selectively bred for.
Any two: high yield, disease resistance, fast growth, docile temperament, large fruit/seeds.
Give two problems caused by selective breeding.
Reduced genetic variation in the population, and a greater risk of inherited diseases/disorders (inbreeding).
True or false? Selective breeding gives an organism a gene from a different species.
False. Selective breeding only uses genes already present in that species; transferring genes between species is genetic engineering.
What is genetic engineering?
Modifying the genome of an organism by inserting a gene, to introduce a desirable characteristic.
What is a vector in genetic engineering?
Something that carries the desired gene into the host cell, usually a plasmid (or a virus).
Give one difference between genetic engineering and selective breeding as ways of producing a desired characteristic.
Genetic engineering inserts a chosen gene directly and works in one generation; selective breeding takes many generations and uses only genes already in that species.
What are the main stages of genetic engineering?
e.g. putting the human insulin gene into bacteria- Cut the gene from the genome and cut open the plasmid with the same restriction enzyme: complementary sticky ends on insulin gene and plasmid.
- Join the gene into the plasmid using ligase: recombinant plasmid.
- Put the plasmid (vector) back into the bacterium, which multiplies: bacteria that make human insulin.
What does a restriction enzyme do in genetic engineering?
Cuts DNA at a specific sequence, leaving sticky ends (unpaired bases).
Why are the gene and the plasmid cut with the same restriction enzyme?
So they are left with complementary (matching) sticky ends, which allows the gene to join to the plasmid.
Which enzyme joins the gene into the plasmid in genetic engineering?
Ligase.
Give two benefits of making a painkiller using genetically modified yeast instead of extracting it from opium poppies.
Any two: yeast grows rapidly so yield is higher, production is faster and cheaper, it takes up less space, and growth is not weather dependent.
Give two risks or concerns of producing a medicine using genetically modified organisms.
Any two: the GM organisms could enter the environment, the drug may not be identical or as effective, possible health risks, and the GM organism could be used to manufacture drugs illegally.
Why are scientists genetically engineering animals for organ transplants?
There are not enough human donors, so it would increase the number of organs available to meet the demand for transplants.
What is another name for selective breeding?
Artificial selection.
Why could a new disease wipe out a whole selectively bred population?
There is little genetic variation, so it is unlikely any individuals carry alleles for resistance; if one is susceptible, they all are.
What is recombinant DNA?
DNA formed by joining together two pieces of DNA from different sources, e.g. a plasmid with an inserted human gene.
Why are some crops genetically modified to be herbicide-resistant?
Herbicide can be sprayed over the whole field: the weeds die but the crop survives, so it has less competition and gives a higher yield.
How could growing a herbicide-resistant GM crop lead to 'superweeds'?
The herbicide-resistance gene could transfer to wild plants or weeds, making them resistant to the herbicide too.