Transcript Example

I.
MUTATIONS
Definition:
Any mistake or
change in the
sequence of DNA.
1. Types of Mutations
A. Point Mutations
- A change in a single base pair.
Example:
Mr. Adoff is real cool!
ATG TCA CGA
Mr. Adoff is _______?
ATG TCA GGA
B.
Frameshift Mutations
- A mutation which causes an entire shift in
the genetic message.
Examples:
Deletion:
ATG ACG GCA TTG TCT GGA
ATG AGG CAT TGT CTG GA_
ATG ACG GCA TTG TCT GGA
Insertion: ATG ACT GGC ATT GTC TGG A
- The entire protein sequence has been changed!
C. Chromosomal Mutations
- Affects large sections of DNA rather
than smaller sections.
- Portions of a chromosome (s) can be
added, deleted or reversed.
Example:
Down Syndrome (Trisomy 21)
- Child has 47, instead of 46
chromosomes.
* What are some characteristics of
someone with Trisomy 21?
Deletion
Duplication
Inversion
Translocation
Selective Breeding
• Only allow organisms with desired traits to
breed with each other.
– Ex- Dog breeding
• Hybridization- crossing dissimilar
individuals to bring together the best traits
of both.
– Mule- cross between a donkey and horse
Selective Breeding cont.
• Inbreeding- continued breeding of ind. with
similar characteristics.
– Ex- different dog breeds
– Can be dangerous due to increased chance
for genetic defects.
II. Genetic Engineering
Definition:
- Making changes to the DNA code of an
organism.
How can I take a gene from one
organism and insert it into another
completely different organism?
A. Recombinant DNA
- DNA made by connecting fragments
of DNA from different sources.
A + B =C
B.
Restriction Enzymes
- Proteins which have the ability to “cut”
pieces of DNA at specific base
sequences.
Examples:
1.
Hae III – Cuts DNA completely in half
between every GGCC sequence.
CATGGCCTATCCGG
GTACCGGATAGGCC
2. EcoRI – Cuts DNA after the G in every
GAATTC sequence.
- Creates “sticky end” pieces of DNA.
“Click image for animation.”
Recognition sequences
DNA
Sequence
Restriction enzyme
EcoRI cuts the DNA
into fragments.
Sticky End
III. Applications for Genetic Engineering
A. Creating Transgenic Organisms
What does “Transgenic” mean?
- An organism that contains “functional”
recombinant DNA.
Examples:
- Glowing Tobacco Plant
- Mice with Human Immune System
- Livestock with extra growth hormone
genes.
- Insect Resistant corn and soybean
- Over 90% of corn & 80% of soybean is a
hybrid.
B.
Importance of Bacteria
- Bacteria are used to produce a variety of
important substances for the health
industry.
Examples:
- Insulin
- Human Growth Hormone
- Blood Clotting Factors
C. How are bacteria “Transformed?”
1. Bacteria contain a circular piece of DNA
called a Plasmid.
2. A gene is removed from a human using
restriction enzymes.
* The same restriction enzyme will be used
to cut open the plasmid.
3. The human gene is inserted into the
plasmid.
4. The bacteria will then reproduce quickly
while producing the item coded for from the
human piece of DNA.
IV. GEL ELECTROPHORESIS
- Process of separating DNA based on
it’s size & charge.
- Each organic molecule will be attracted to
either a positive or negative charge.
STEPS:
1. Cut DNA with restriction enzymes.
2. Place DNA in agarose gel and add
buffer solution.
3. Turn on current and allow DNA pieces
to separate. (DNA is negatively charged.)
Click image for animation.
Polymerase Chain Reaction
• PCR is used by geneticists to make copies
of DNA strands.
Cloning
• A member of a population of genetically
identical cells produced from a single cell.