Download File - Cowan Science

Biotechnology
Notes
Unit 3
IN 81
Define Genetic
Engineering
• Process where DNA is split into fragments and
new DNA pieces are inserted
• Restriction enzymes cut DNA at certain places
• Carriers are then used to insert DNA splices
• Now referred to as recombinant DNA or
transgenic
Animation:
http://www.hhmi.org/biointeractive/dna/animation
s.html
Applications of recombinant DNA
• Bacteria: reduce frost
damage to crops, produce
antibiotics
• Plants: resistant to
herbicides, increase yield in
crops
• Animals: cloning of
endangered species, gene
therapy,
Interesting Fact: About 40 different crops are approved for marketing in the US.
That means 60-70% of the foods at your grocery store contain genetically
engineered products! They are not labeled.
• cells whose job in
the body is not yet
determined
• cell “turns on”
specific genes in the
stem cell to make
them specialized
• For example, stem
cells can become
skin cells, bone
cells, red blood
cells, nerve cells, or
skeletal muscle
cells.
Stem Cells
What are they used for?
• Repairing damaged tissue, replacing
organs, treat Alzheimer’s or Parkinson’s
diseases
What’s the big deal?
• Stem cells must come
from aborted or
miscarried fetuses
• Currently banned
• the creation of an organism
that is an exact copy of
another
• occurs naturally in nature
(identical twins)
• may be used for cloning stem
cells, reviving endangered or
extinct species, reproducing a
deceased pet or child.
How is a clone made?
• An early stage embryo is split
into cells before those cells
have differentiated, the cells
are then grown separately,
and develop into identical
embryos and can be implanted
into surrogate mothers.
Cloning
Conceiving a Clone!
• Try this science lab as a class:
• http://library.thinkquest.org/24355/data/cre
atenav.html
Describe DNA fingerprinting
• Sample of DNA is
exposed to restriction
enzyme which cuts it into
pieces
• DNA is loaded into a gel
and run through
electrophoresis machine
• Gel Electrophoresis
Demo
• Since DNA is cut at
certain sequences, each
piece is a different length
and weight
• Pieces that are heavier
stay at the top of the gel,
lighter will “run” to the
bottom
• Every person is
genetically different, so
DNA fingerprints are
different
DNA fingerprinting applications
• Can be used to identify or eliminate suspects when
genetic material has been collected at a crime scene
• Can be used to determine paternity of a child, or
establish other family relationships
• Can be used to identify a deceased person
HOW DNA IS USED TODAY
–http://www.agresearch.co.nz/scied/search/tools/electro/activity_electro_fingerprinting_police.htm
C. Manipulating DNA
1. Scientists use knowledge of DNA to change DNA molecules
2. Techniques used to extract DNA, cut into smaller pieces and identify
base sequences, make unlimited copies of DNA
3. Genetic engineering- making changes to DNA code and putting back
into cell (by injection into cell, by bacteria, viruses)
V. Applications of Genetic Engineering
A. Transgenic organisms- contains genes from other organisms
1. Transgenic microorganisms- bacteria used to
produce many important substances for health and
industry (e.g. transformed bacteria now make insulin,
growth hormone, clotting factor cheaply and in great
abundance)
Transgenic tobacco plant- glows in
the dark. Produced by transferring a
gene from a firefly into a tobacco
plant