Transcript File - singhscience

Genetic Engineering
• Give brief examples of products made
using genetic engineering (D)
•Describe the process of making human
insulin through genetic modification (C/B)
• Discuss the benefits, drawbacks and
risks with genetically modified products
(A/A*)
A quick recap!
You need a mini white board, pen and a board
rubber
1. Which bases pair together?
a) C and T, A and G.
b)G and T, A and C
c) C and G, A and T
d)T and C, G and A
2. Proteins are made up of:
a) Long chains of amino acids
b)Long chains of chromosomes
c) Groups of chromosomes
d)Groups of cells
3. Each amino acid is coded for by:
a) Four base pairs.
b) Three bases called a triplet.
c) The entire DNA
d) Two bases called a couple.
4. Each gene contains the sequence of
bases for how many proteins?
a) One
b)Two
c) Three
d)Four
5. What is the genetic code?
a) The order of the chromosomes
determines how proteins are made.
b) The type of gene determines what each
protein does.
c) The proteins determine what the DNA
structure will be.
d) The order of DNA bases which determines
the sequence of amino acids in a protein.
Something to think about:
• What is genetic engineering?
• Does it happen in the UK
• Do we use GM products in the UK and can you
give an example?
• What is the most commonly engineered type
of organism?
• On balance, do you think it is a good or bad
thing?
Uses of Genetic Engineering
1. Reducing Vitamin A Deficiency
• Beta-Carotene is used by our bodies to make
vit A. Vit A deficiency a big problem in parts
of South Asia and Africa.
• Golden rice is a variety of GM rice. It contains
2 genes from other organisms which together
enable rice to produce beta-carotene.
• So growing Golden rice in these places means
fewer people suffer from vit A deficiency.
Plants with extra vitamins
Rice can be genetically modified to make beta-carotene, a
substance that is converted into vitamin A in the body.
The colour of the rice is
an indication of how
much more beta-carotene
it contains.
The GM rice is called
‘Golden Rice’ and is being
developed to help fight
vitamin A deficiency and
blindness in developing
countries.
Crops can be given extra genes for new and useful
characteristics. They are genetically modified (GM).
 pest resistance – wont be damaged by
insects or other pests
 frost resistance – wont be damaged by the
cold
 disease resistance – wont get as many
diseases
 herbicide resistance – wont get damaged by
chemicals
 drought resistance – dont need as much
water
 longer shelf life – wont go off as quickly
Increasing Crop Yield
1. GM crops have had their genes modified, e.g.
To make them resistant to herbicides.
(chemicals used to kill weeds)
2. Fields of crops can be spray with herbicide
and all the plants except the GM crops are
killed. Increase yield > make more food.
Changing the genetic code
Bacteria are often genetically engineered to produce useful
chemicals because their DNA is loose in the cytoplasm, making it
easy to modify. They also grow and replicate quickly.
loose strand of
main DNA
plasmid
– small ring of
additional DNA
A new gene can be inserted into the plasmid and the bacteria
then produce the protein for which the gene codes.
Producing insulin with bacteria
Genetically-engineering bacteria
Genetic engineers remove the gene that code for
human insulin from a human body cell using
enzymes.
This is extracted, purified and packaged in sterile
bottles for diabetics.
The bacterium then divides to make identical
bacteria.
The human gene produces human insulin
They put this gene into a suitable bacterium.
Bacteria can produce human insulin for this
purpose.
Bacteria can produce human insulin for this purpose.
Genetic engineers remove the gene that code for
human insulin from a human body cell using
enzymes.
They put this gene into a suitable bacterium.
The bacterium then divides to make identical
bacteria.
The human gene produces human insulin
This is extracted, purified and packaged in sterile
bottles for diabetics..
Answers
Controversy...
• GM crops will affect the number of weeds and
flowers and therefore wildlife. Reducing
Biodiversity.
• Are GM crops safe? People are worried they
may develop allergies.
• Transplanted genes may get out into the
natural environment. For example the
herbicide resistance gene may be picked up by
weeds, creating a new ‘super weed’.
Should GM crops be allowed?
What is gene therapy?
Children with faulty immune systems have been cured by adding
genes to their bone marrow cells. This is called gene therapy.
1. A ‘healthy’ version of the faulty gene is
cut from normal DNA and copied.
2. The gene is added to a harmless virus.
3. The virus carries the gene into the patient’s cells,
where the healthy gene is released.
4. The patient’s cells can then make the correct product of
the gene. The patient is then cured.