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CHAPTERS 5.14 TO 5.17
THE POTENTIAL OF BIOTECHNOLOGY
Ms. Doshi
Medicines produced by recombinant DNA
technology
Human Insulin
-helps diabetics
-insulin injections keeps diabetes under control.
Human Growth Hormone (HGH)
- produced by pituitary gland
- helps with dwarfism
- increases strength and endurance
- illegal use of HGH among athletes
Erythropoietin
- produced by kidneys
- hormone that regulates production of RBCs (red blood cells)
- If low, can have nutritional deficiencies, lung disease, and anemia
- Now, used to treat anemia.
- EPO is used in “blood doping” scandals in professional cycling because it
increases oxygen carrying capacity
- can get heart attack if not used for medical purposes
Genetic Screening
• Identify genetic conditions before birth, or
try to predict these conditions before
conception.
• This can be done through many methods
such as extensive pedigrees and biochemical
testing.
• Genetic screening is often the job of a
genetic counsellor
Methods of prenatal diagnosis
Prenatal diagnosis can tell us the sex of the child
as well as the presence of other genetic
conditions and known disorders.
The most widely used methods are:
– Amniocentesis
– Chorionic villi sampling (CVS)
– Fetal cells are isolated and cultured
Testing for Downs Syndrome
Prenatal diagnosis tests can be used to detect
genetic disorders such as downs syndrome.
Downs syndrome is often tested for in older
mothers because there is an increased risk with
maternal age (1 in 100 chance if mother is over
40).
There are many ethical and religious concerns
with this testing.
Gene Therapy
Transfer normal genes into individuals with
genetic disorders
This therapy is still undergoing research.
Gene Therapy
There are three strategies:
1- Gene insertion- uses an agent (e.g. a virus) to
insert a gene into a target cell. This can be
restricted to certain areas. E.g. pancreatic cells
for diabetes treatment.
2-Gene modification- Gene is modified
chemically to try and change its code (very
delicate).
3- Gene surgery- defective gene is removed and
then replaced (hard to do!)
SCID: Gene Therapy Example
1. a malfunctioning gene
disrupts normal white
blood cell production.
2. bone marrow stem cells
are infected with a
transgenic virus containing
the gene
3. This is then injected back
into the baby.
4. 2 babies died and research
stopped.
Why are there problems with gene
therapy?
1. Difficult to get the working gene in the right
area of the cell.
2. Difficult to get the working gene into enough
cells and at the right rate to produce a
physiological effect
3. The transfer organism goes into the wrong
cells.
4. Difficulty with regulating gene expression.
Cloning
Can clone tissue, organ, or
an entire organism.
In 1996, Dolly was born
Dolly was the first
mammal cloned from an
adult body cell (cell from
mammary gland in adult
sheep).
DNA Fingerprinting
STRs
• short tandem repeats
• used to determine a
person’s genetic
fingerprint
• have a short sequence
(4/5 nucleotides) that
repeats again and again.
Creating a DNA Fingerprint
To find the bad guy:
Look at 13 different STR
locations (FBI).
As a result, the DNA
fingerprint has
26-number fingerprints.
The probability that two
individuals have the same
genotype is extremely
low!
Questions
1. What are 3 medicines produced by recombinant
DNA technology?
2. What is genetic screening?
3. Who does genetic screening?
4. What does prenatal diagnosis tell us?
5. What methods do we use in prenatal diagnosis?
6. When do we test for downs syndrome of a child?
7. What is gene therapy?
8. SCID is an example of what kind of gene therapy?
9. What was the first mammal to be cloned?
10. How many STR locations does the FBI use to
identify a criminal?
Assignment-to do
• Show students how to login to Gizmos.
• Use Internet Explorer 7 or higher. OR Mozilla Firefox 3x or
higher on your computer at home! Work with partner or in
group of 3.
• Step 1: Go to http://www.explorelearning.com
• and follow Gizmos Instructions Sheet in Kakao Group.
School Holiday: 4/15
• Assignment 1 deadline: 4/21 at 9 AM
• Gizmos Assignment
• Do Assessment Questions in Gizmo AND do Gizmo
Worksheet
• Any Questions or Problems: Kakao Me!
Any Questions?
Any Answers?
Any Comments?