Open - Inverness Royal Academy

define genetic engineering


•

the transfer of gene(s) from one organism to another


•

if genes are transferred between different species
–

a
genetically modified organism (GMO)

or
transgenic

organism
is produced


state the advantages of genetic engineering over
artificial selection


•

new varieties produced in one generation


•

element of chance removed


•

allows transfer of genes between species


describe two methods of locating genes on a
chromosome






banding patterns


•

when stained chromosomes show a unique pattern of light
and dark bands


•

by comparing the banding pattern on normal and mutated
chromosomes it is possible to identify the location of genes
responsible for a specific characteristic





gene probes


•

a gene probe is a
small piece of single
-
stranded DNA or
RNA

with a
base sequence complementary

to that of the gene
being sought


•

a radioactive or luminescent chemical (
marker
) is attached


•

the DNA containing the desired gene is
cut
-
up into small
fragments

using enzymes


•

it is then converted into
single
-
strand format

using
chemical or heat treatment


•

the gene probe is then added and it
attaches to the DNA
fragment containing the desired gene


state the name and function of the enzymes involved
in genetic engineering


•

endonuclease enzymes
are used to cut the DNA into
fragments








•

ligase enzymes are used to seal new gene(s) into the
genome of another organism

sequence the stages involved in
genetic engineering

(transfer of the
human insulin gene

to the
E. coli

bacterium
)


•

human DNA cut into fragments

by an endonuclease enzyme

•

plasmids (small rings of DNA) removed from
E. coli

–

all
contain gene for resistance to an antibiotic

•

plasmids cut open

using same endonuclease enzyme

•

human DNA fragments inserted into plasmids

using a
ligase enzyme

•

recombinant plasmids mixed with
E. coli

cells

–

only some
take
-
up a plasmid

•

E. coli

grown on agar containing antibiotic

–

those that
have not taken
-
up a plasmid killed

•

gene probe

added to identify
E. coli

colony that contains
plasmid with human insulin gene

•

E. coli

grown in a
fermenter

–

produce human insulin

•

insulin
purified

and made available to diabetics



name examples of GMOs and their products /
characteristics


•

E. Coli

–

produce
insulin
,
human growth hormone

•

sheep
–

factor VIII blood
-
clotting protein

produced in their
milk

•

crop plants
–

improved yields
,
enhanced disease
resistance
,
herbicide resistance
,
increased nutritional value
,
wider

environmental tolerance


discuss the potential positive and

negative impacts of genetic engineering