Genetic engineering is cool -
This is a new science with exciting possibilities, but dangers too. The basic idea is to move sections of
DMA (genes ) from one organism to another so that it produces usefu l biological products. We presently
use bacteria to produce human insulin for diabetes sufferers, and also to produce human growth
hormone for children who aren't growing properly.
Genetic engineering involves these important stagt.
1) The useful gene is "cut" from the DMA of, say, a human.
2) This is done using "enzymes."
Particula r enzymes will cut out particular bits of DMA.
3) Enzyme s are then used to cut the DMA of a bacterium, and
the human gene is then inserted.
4) Again this "splicing" of a gene is controlled by certain
5) The bacterium is now cultivated and soon there are millions
of similar bacteria all producing, say, human insulin.
6) This can be done on an industrial scal e and the useful
product can be separated out.
So, we've turned nast y old bacteria into a useful biological factory. Phew, that's modern science for you.
the bacteria are then
grown like mad...
The same approach can also be used to transfe r
useful genes into animal embryos. Sheep, for
example, can be genetically engineered to produce
useful substance s (for example, medicinal drugs) in
their milk! This is a very easy way to produce
2) Insects also have their uses. Mosquitos may, in the near future, be used
to combat diseases such as "malaria." The mosquitos that normally
spread malaria are being genetically engineered to produce the malaria
vaccine. Therefore instead of giving the diseas e to people, they will soon
hopefully be immunizing them instead.
Nothing's been done to etop the
Mosquitoes that stop you getting Malaria — now that's clever...
They could ask you about any of the details on this page. The only way to be sure you know it: cover
the page and write mini-essay s on both topics. Then see what you missed, and try again...
Geneti c Engineering
Q1 Genetically engineered animals can be used to produce useful products,
a) Malaria is a disease which is spread by mosquitoes.
Explain how through geneti c engineering, mosquitoes
can be used to help in the fight agains t malaria.
b) Genetically engineered sheep can produce
useful substances, such as medicinal drugs.
How are these substance s collected from
Q2 Read the following article about insulin production.
Insulin is a hormone that is used to treat sufferer s of diabetes.
The hormone is naturally produced in small quantities in the
bodies of animal s (including humans). It was previously
extracted from domesticated animals, such as pigs. Today insulin
is produced by bacteria. DMA from animals can be inserted into
bacteria cells. The DNA instructs the bacteria to produce insulin.
a) The bacteria that produce insulin have been genetically engineered.
Explai n what this means.
b) Name another useful substanc e that is produced by genetically engineered bacteria.
Q3 Crop plants can be genetically engineered to make them resistan t to weedkillers.
A gene for weedkiller-resistance is put into some bacteria, and the bacteria are
then allowed to infect a plant. In the right conditions, the bacteria will insert the
weedkiller-resistance gene into the plant's genome.
a) Describe the procedure for inserting a gene
for weedkiller resistanc e into bacteria.
b) What is the advantag e of having crop plants
that are resistan t to weedkillers?
SECTION THREE — GENETICS