SB4g Genes in Agriculture and Medicine Flashcards
advantages of selective breeding? 3
~advantageous alleles can be selected and passed on to offspring
~increased yield e.g. in milk, meat or grain
~disease resistance can be increased
disadvantages of selective breeding? 3
~some alleles become rare or disappear and may have been useful in the future
~diseases may affect organisms as they are bred in huge numbers
~poor animal welfare
advantages of genetic engineering? 4
~resistance to pests and diseases
~less reliance on the use of insecticides and herbicides
~desired characteristics can be selected and produced quickly, in large numbers
~produce useful substances cheaply
disadvantages of genetic engineering? 3
~seeds for GM crops are extremely expensive
~GM crops may cross breed with wild varieties, passing on resistance genes
~genes may have unknown health consequences - no evidence
genetic engineering main stages
~DNA taken from a human cell
~use a restriction enzyme to cut out the gene for insulin from DNA. this leaves sticky ends
~use a restriction enzyme to cut the plasmid out of a bacterial cell
~use the same restriction enzyme to cut a section of DNA from the plasmid
~insert the gene for insulin into the plasmid
~use a ligase enzyme to join the ends of the DNA. the sticky ends will match and join up
~put plasmid with the insulin gene back into a bacterial cell
~leave bacteria to divide
~insulin is removed and purified
~ready for use in humans
what is the bacteria called after the plasmid with insulin gene is put in?
a vector
gene splicing?
process of cutting out a gene from the DNA of one organism and inserting it into the DNA of another
Describe the advantages of making insulin using genetically modified bacteria rather than extracting it from animals. (2 marks)
Insulin from GM bacteria is cheaper and suitable for vegans or people who do not eat pork or beef for religious reasons
