Transcript 3.5 – Genetic Modification & Biotechnology

3.5 – Genetic Modification &
Biotechnology
I. PCR –
Polymerase
Chain Reaction
A.
B.
For other
techniques,
substantial
quantities of DNA
are necessary
PCR is used to
make millions of
copies of a DNA
sample so that
other
biotechnologies
can be done
http://highered.mcgrawhill.com/sites/9834092339/student_view0/chapter18/p
olymerase_chain_reaction.html
II. Gel Electrophoresis -Used to separate
fragments of DNA
A. Restriction enzymes (endonucleases) are used
to cut up DNA into fragments of varying sizes
B. Fragments placed in holes at one end of a
slab of charged gel
C. DNA fragments move through gel towards
positive pole (WHY?)
D. Smaller pieces move farther faster than
larger pieces (WHY?) creating a banded
pattern
III. DNA Profiling/Fingerprinting
A. Match an unknown sample
of DNA with a known sample
B. If patterns are the same =
same person
Patterns similar = probably
related
C. Used for paternity testing,
criminal investigations,
determining evolutionary
and ecological relationships
https://www.youtube.com/watch?v=ZAuWYP7rt0A
IV. Cutting and Pasting Genes
A. Restriction enzymes (endonucleases) find and
recognize a specific sequence of base pairs along
the DNA molecule and cut it at specific points
B. For pasting a gene, DNA ligase recognizes
sticky ends and fuses
V. Gene Transfer
A. AKA gene modification – take a gene out of one
organism and place it into a different organism
1. Used to create cold- and pest-resistant crops
B. REMEMBER – Universal Genetic Code
VI. Cloning
A. Reproductive cloning - Making copies of
whole organisms
B. Therapeutic cloning - Making copies of
embryonic/adult stem cells (AKA stem cell
research)
1. Its aim is to develop cells which have not yet
gone through the process of differentiation
2. Ethical Issues surrounding therapeutic cloning
a. Therapeutic cloning starts with production of human
embryos - Is it ethically acceptable to generate a new
human embryo for the sole purpose of medical research?
b. In nature, embryos are created only for reproduction
and many people believe that using them for
experiments is unnatural and wrong
c. Embryonic stem cells has lead to major
breakthroughs in human biology
d. Scientists are coming closer and closer to growing
skin to repair serious burns, growing new heart muscle to
repair an ailing heart, growing new kidney tissue to
rebuild a failing kidney
e. With some exceptions, the majority of researchers are
against the idea of reproductive cloning in humans