Transcript National 5 Biology - Oronsay Bed & Breakfast

National 5 Biology
Genetic Engineering
Genetic Transfer
• It is possible to transfer genetic
information from one cell to another.
• In bacteria there is a chromosome
which is circular and smaller circles of
DNA called plasmids.
• The chromosome and the plasmids are
made of DNA.
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Genetic Transfer
• When bacteria divide, the chromosome
and the plasmids are replicated.
• Genetic information can be passed from
one cell to the next naturally.
• It can also be passed from one cell to
the next artificially by genetic
engineering.
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Genetic Transfer
• Viruses require living cells before they
can replicate.
• When a virus attacks a cell its DNA is
injected into the host cell.
• This means that the viruses DNA and
the host cell’s DNA become joined.
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Genetic Transfer
• When the host cell divides by mitosis,
the virus’s DNA is also copied.
• Using this knowledge, we can now alter
the genetic code of cells using genetic
engineering.
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Genetic Transfer
• An organism which has been altered in
this way is described as being
genetically modified.
• In this way, we can ‘programme’
bacterial cells to produce things that
they would not normally produce.
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Genetic Engineering Stages
• Identify the section of DNA containing
the gene we require.
• Cut the gene out using an enzyme.
(genetic scissors)
• Remove the plasmid from the bacterial
cell.
• Using the same enzyme, open the
plasmid,
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Genetic Engineering Stages
• Insert the gene into the plasmid using
another enzyme (genetic glue).
• Replace the plasmid into the bacterial
cell.
• Allow the bacterial host cells to divide
naturally.
• The bacterial cell will now produce the
protein we want which was coded in the
original DNA.
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Genetic Engineering
• This process of genetic engineering can
be used to produce such proteins as
insulin, which is required to treat
diabetes.
• It has also been used to produce human
growth hormone.
• Other examples include more nutritional
plant products and disease resistance.
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Genetic Engineering
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