Gene transfer involves taking a gene from one organism and placing it into another. Examples given are genes from fish that have been inserted into plants to make them resistant to freezing, and Bt corn which contains genes from Bacillus thuringiensis bacteria that produce toxins killing insect pests. Cloning techniques allow for precise copying of genes. Restriction enzymes cut DNA at specific sequences, allowing genes to be removed and inserted into other organisms using DNA ligase. Transgenic plants and animals are created this way, with potential uses including producing crops resistant to pests or dairy animals with higher milk output. Cloning can also be used for therapeutic purposes like stem cell research. There is debate around the ethics of altering organisms' genetic identities

1. 3.5 continued

2. Gene Transfer
 Technique of taking a gene out of one organism
and placing it in another.
 Possible because the genetic code is universal.
 Examples:
 Genes from fish put into produce to resist freezing
 Bt corn that resists pests

3. What is Bt?
 Bacillus thuringiensis
(Bt) is a soil bacterium
that produces insecticidal
toxins. Genes from Bt can
be inserted into crop
plants to make them
capable of producing an
insecticidal toxin and
therefore resistant to
certain pests.
 If Bt crops kill insects,
what happens to the local
ecosystem that relies on
the insects for food or

4. TOK
 Is it ethically acceptable to alter an organisms
genetic identity?
 If the organism did not have that gene in the first
place, could there be a good reason for its
absence?
 Why are people so worried about this new
technology? In selective breeding, thousands of
genes are mixed and matched. With GMO’s, only
one is changed. Is that not less risky?
 Would strict vegetarians be able to eat a fruit with
a fish gene in it?

5. Cloning
 Restriction enzymes
(endonucleases)
recognize a sequence of
4-6 bases and cut the
DNA at that point.
 The gene can then be
removed.
 DNA ligase is used to
paste the genes into
another organisms
genome.

6.  The gene must be inserted into a plasmid from a
host cell
 Host DNA is cut using RE’s
 The gene to be copied is inserted
 Ligase seals it together
 The plasmid is now called a recombinant plasmid
and can be used as a vector, which is a tool for
introducing a new gene into an organism’s
genetic makeup.

7.  Plasmid is put into host bacterium
 Bacterium reproduces, copying the gene
 The gene is expressed and the protein that the
gene codes for is synthesized.

8. Transgenic Plants
 Undesirable gene can be removed  gene no
longer expressed
 Desirable gene inserted new trait expressed
 Corn that kills pest species
 Golden rice
 Soy with higher levels of oleic acid
 Roundup resistant alfalfa

10. Transgenic animals
 Can be used for medical
treatments
 Dairy animals are commonly
used
 High milk output
 Short generation times
 Gene inserted into the
animal’s genome
 Protein produced in the
animal’s milk
 Protein the isolated from the
milk and used in medical
treatment

11. Natural Cloning
 Some plants and
animals are capable of
cloning themselves
 Pro’s- no need for
fertilization, all desirable
characteristics passed
on to offspring
 Con- all weaknesses
passed on to offspring
 Example: some types of
sharks have undergone
parthenogenesis in
captivity

12. Reproductive Cloning
 Makes a whole individual
 Undifferentiated cells can be removed from a
developing embryo; will result in identical
organisms
 Somatic cell nuclear transfer
 Somatic cell is collected and the nucleus is
removed
 Unfertilized egg is collected and the nucleus is
removed
 Electrical current is used to fuse the egg and
nucleus from the somatic cell
 Cell develops in vitro
 Embryo placed into womb

13. Therapeutic Cloning
 AKA stem cell research
 Does not make whole individuals, but embryos for
stem cells instead
 Undifferentiated cells are cultured
 These cells can then be made into any type of
cells/tissues for medical treatment

14. TOK
Some people think that both methods of cloning are
unacceptable, others think both are fine, and some
are in between. What is your stance?