2. I. Manipulating Genes
DNA Technology: technology involved
in genetic engineering that can be used
to cure diseases, to treat genetic
disorders, and to improve food crops.
3. A. Restriction Enzymes: bacterial enzymes that cut
long strands of nucleotides into smaller segments.
1. Recognize specific sequences of nucleotides (bases)
and cut the DNA at a specific site within the sequence.
2. In one chain, the sequence runs left to right and on
the complementary chain the sequence runs
right to left.
I. Manipulating Genes
4. 3. Single chain “tails” of DNA called
sticky ends are created on each DNA
segment by the action of the restriction
enzymes.
4. Sticky ends readily bind to
complementary chains of DNA.
I. Manipulating Genes
5. I. Manipulating Genes
5. Pieces of DNA that have been cut
with the same restriction enzyme can
bind together to form a new
sequence of nucleotides.
6. Restriction enzymes can be used to
isolate (cut out) a specific gene.
6. B. Cloning Vectors: A DNA carrier used to clone a
gene and transfer it from one organism to another.
1. Once a gene has been isolated, that small piece
of DNA can be placed into a cloning vector and can
be introduced into an organism.
2. Many bacteria contain a
cloning vector called a plasmid.
I. Manipulating Genes
7. Plasmid: a ring of DNA found in bacteria in
addition to it’s main chromosome. It can be used
to transport genes from one organism to another.
I. Manipulating Genes
8. Process of using a cloning vector:
a) A plasmid is removed from a bacterial cell
b) Using a restriction enzyme,
the plasmid is cut and a donor
gene is spliced in.
-Donor gene: a specific gene
that is isolated from another
organism and introduced
into a cloning vector.
I. Manipulating Genes
9. c) the plasmid is returned
to the bacterial cell, where
it replicates as the
bacterial cell divides. This
clones the donor gene.
d) the bacteria containing
clones of the donor gene
can then be used to infect
other organisms and
transfer the gene to them.
I. Manipulating Genes
10. A. In some cases, plasmids are used to clone a
specific gene so that the bacteria will produce a
specific protein.
1. For example: insulin is a protein that controls
sugar metabolism.
II. Transplanting Genes
11. II. Transplanting Genes
a) People who are diabetic do not make
the hormone insulin. Insulin allows sugars
to travel from the blood into the cells
where they are transformed into energy.
b) A large volume of insulin can be
produced by cutting out the human gene
and cloning it using a plasmid.
12. B. Process:
1. Isolating a gene:
a. DNA is removed from a human cell to isolate
the gene that produces insulin.
b. A restriction enzyme is used to cut the
human DNA into separate genes, this includes
the gene for insulin.
II. Transplanting Genes
13. 2. Producing Recombinant DNA:
a) Recombinant DNA: combination of
DNA from two or more sources.
b) Inserting a donor gene (human gene
for insulin) into a cloning vector
(bacterial plasmid) results in a
recombinant DNA molecule.
II. Transplanting Genes
14. 3. Cloning DNA:
a) the plasmid containing recombinant DNA is
inserted into a host bacterium.
b) the transgenic bacteria is placed into a nutrient
medium where it can grow and reproduce.
c) within each bacterium, the plasmid is copied
many times, and the donor gene for insulin is
cloned.
II. Transplanting Genes
15. d) thousands of bacteria are produced very
quickly through mitosis.
e) the transgenic bacteria can be used to
produce large amounts of insulin.
II. Transplanting Genes
16.
17. 1. Once a donor gene is transferred to a host
cell, it is transcribed and translated as though it
were in its own cell.
a) not all of the genes in a cell’s genome are
expressed.
b) genes are often turned off until
the proteins they code for are
needed
C. Expression of Cloned Genes
18. III. DNA Fingerprints
Uses:
1. The banding patterns of DNA
fragments from two different
individuals may be compared to
see if they are related (ex.
Paternity tests)
2. DNA fingerprints of members
of two different species can be
compared to determine how
closely species are related.
3. Using DNA fingerprint to
compare samples of blood, hair,
or tissue found at a crime scene
with a suspect’s blood sample
may help in solving crimes.
19. C. Making a DNA Fingerprint
1. RFLP (restriction
fragments length
polymorphism) Analysis:
method for preparing a DNA
fingerprint.
a) involves extracting
DNA from blood, hair,
or tissue and cutting it
into fragments using
restriction enzymes.
b) fragments of DNA are
then separated using a
technique called gel
electrophoresis.
20. C. Making a DNA Fingerprint
2. Gel electrophoresis:
separates nucleic acids
or proteins (amino
acids) according to their
size and charge.
a) Samples of DNA being
compared are placed in
wells made on the gel
b) An electric current is
then run through the
gel
21. c) DNA fragments (“-” charge)
migrate towards the “+“ end of the
gel
d) The smaller DNA fragments
migrate faster and farther down the
gel than the longer fragments.
e) The DNA fragments that have
been separated on the gel are
stained in order to be seen.
22. 3. Accuracy of a DNA
fingerprint:
The complete nucleotide
sequence of each individual
is unique for each person
(except identical twins).
Therefore, everyone’s DNA
fingerprint will be different.
DNA fingerprints are
99.9999% accurate.
23. IV. Polymerase Chain Reaction
Can be used to make copies of
selected segments of DNA for a
DNA fingerprint.
Requires:
a) A primer: artificially
made single-stranded
sequence of DNA.
b) When these ingredients
(DNA and Primer) are
combined and incubated, the
selected regions of DNA quickly
double.
24. c) Every five minutes the
sample of DNA doubles again,
resulting in many copies of a
sample in a short amount of
time.
d) the new copies of the DNA
sample can then be used to
make a DNA fingerprint.
e) Used in
Paternity tests
Diagnosis of genetic
disorders
Study of ancient fragments
of DNA
25. V. Human Genome Project
A. Goals:
1. To Determine the nucleotide sequence of the Human
genome and to map the location of every gene on
each chromosome.
2. To compare the human genome with genomes of
other organisms in an effort to provide insight into
fundamental questions about how genomes are:
a. Organized
b. How cellular differentiation and
growth are under genetic control
c. How gene expression is controlled
d. And how evolution occurs.
26. B. It is hoped that the knowledge gained
from the Human Genome Project will improve
diagnosis, treatments, and even provide
cures for genetic diseases.
1. Identifying these genes and defective
proteins for which they code may make it
possible to design therapies aimed at
correcting the gene defects responsible for
the disorder.
27. VI. Gene Therapy and Cloning
Treating a genetic disorder by introducing a
normal gene into a cell or by correcting a
gene defect in a cell’s genome.
A. Is well suited for treating genetic disorders
that result from a deficiency of a single
enzyme or protein.
Example: cystic fibrosis, lung cancer, AIDS,
ovarian cancer, brain cancer
28. A. Many medicine are proteins that can be mass-
produced in a less expensive way through DNA
technology.
Examples:
1. Insulin: controls sugar metabolism; used to treat
diabetes.
2. Colony-Stimulating Factors: used to treat immune
deficiency by stimulating the production of white
blood cells
3. Erythropoietin: used to treat anemia by stimulating
the production of red blood cells.
29. 4. Human Growth Hormone: used as a
treatment for dwarfism; causes bones to
elongate.
5. Interferon: used to treat viral infections and
cancer by preventing the replication of
viruses
6. Interleukins: used to treat HIV and cancer by
activating and stimulating different kinds of
white blood cells.
30. - Genetically Engineered Vaccines
- Many diseases are combated by
prevention, using vaccines made by
genetic engineering.
31. Increasing Agricultural Yields
1.DNA technology has been used to
develop new strains of plants,
which in turn can be used to
improve food and crop yields.
A. Examples: Tomatoes and
hornworms:
-by transferring genes for enzymes
that are harmful to hornworms
into tomato plants, scientists can
make tomato plants toxic to
hornworms and effectively
protect the plants from these
pests.
32. B. Wheat, cotton, and soybeans:
-have been created to be resistant to
weed controlling chemicals
1) herbicide: weed controlling chemicals.
2) such herbicide resistant crops can be
protected from weeds more easily and
less expensively than crops that are
susceptible to the herbicides
33. -The examples given above are also
classified as therapeutic cloning
-Therapeutic cloning uses genetic
engineering to help treat and cure
diseases.
34. Safety and Environmental Issues
Many people are concerned about the
safety of genetically engineered foods.
the concern is that the food produced
by genetic engineering could contain
toxic proteins or substances that can
cause allergies in people who consume
them.
35. Foods produced by transgenic crops can
be sold without special permits or labels
if the product is identical to products
produced by nontransgenic crops.
Example: corn, tomatoes
36. Concerns:
a) genetically engineered crops could spread
into the wild and wipe out native plant
species.
b) transgenic crops could transmit their new
genes to other species in neighboring areas.
Example: superweeds produced by
rice and lawn grasses exchanging
pollen with native species
37. Reproductive Cloning
-Involves the making of a whole new
organism from a still living organism
-There is no sexual reproduction or
fertilization involved
-Sheep, donkeys, and a number of plants
have been cloned
-Human cloning is still far off in the future
