genetic engineering and cloning

Question 1

process of genetically engineering bacteria to produce human insulin

Answer 1

• human insulin gene located and isolated (chromosome 11)
• gene cut from the rest of the chromosome using DNA restriction enzyme
• a plasmid is extracted from bacterium and cut with same restriction enzyme. this produces complimentary cuts called sticky ends. they can be joined together
• human insulin gene is attached to plasmid using DNA ligase enzyme. plasmid is vector because it carries human DNA
• plasmid is reinserted into bacterium- now transgenic

Question 2

manufacturing- insulin

Answer 2

• transgenic bacteria placed into fermenter in order to increase in number
• if it has enough nutrients and kept at optimum conditions they will produce human insulin. plasmids contain non-essential genes which is why they can be modified without killing the bacterium
• insulin released by bacteria is collected and distributed

Question 3

advantages and disadvantages of genetically modified plants:

Answer 3

adv-
more precise method than selective breeding
higher crop yield/better food quality
disease resistant
less pesticide- less pollution

disadv-
not accepted by public
long term affects unknown
may affect food chains or environment
reduces variation

Question 4

micro propagation

Answer 4

stage 1
explant cut from desired plant and grows into callus (small ball of cells)
single cells taken from callus and enter
stage 2
grown into individual cloned plant
stage 3
rooting and acclimatizing 
stage 4
transfer new plants to soil

Question 5

cloning mammals

Answer 5

donor cell from sheep's udder
egg cell from adult female sheep
egg cell- nucleus removed
two cells fused using electric shock
fused cell divides normally
embryo placed in uterus of foster mother
embryo develops normally into lamb