Genetic Disorders - armstrong

Inheritance of Genetic Traits
Genetic code
 1966
 The Genetic code was
 Scientists are able to
predict characteristics
by studying DNA.
 This leads to genetic
engineering, genetic
DNA Fingerprinting
 The late 1980's.
 An international
team of scientists
began the project to
map the human
 The first crime
conviction based on
DNA fingerprinting
in Portland Oregon.
Human Genome Project
• Completed in 2003
• 13-year project
Human Genome Project
Human Genome Project
 A project that set out to detect all
the genes
 Will help begin to treat diseases by
altering our very genes‚ giving us
new ones if ours are nonfunctional, changing bad genes for
good ones.
Gene Therapy
 1990.
 Gene therapy was
used on patients for
the first time.
DNA Testing
 1995.
 DNA testing in
forensics cases gains
fame in the O.J.
Simpson trial.
Cloning Begins
 1997.
 Dolly the sheep - the
first adult animal
 http://www.schooltube.
Genetic Disorders
Sickle Cell Anemia
 Inherited
 red blood cells,
normally disc-shaped,
become crescent
 function abnormally and
cause small blood clots
 These clots give rise to
recurrent painful
episodes called "sickle
cell pain crises".
Sickle Cell
 Sickle cell disease is most commonly
found in African American
populations. This disease was discovered
over 80 years ago, but has not been given
the attention it deserves.
 inherited from a parent
 a mistake that is present in the
DNA of all body cells.
 The mutation is copied every time
body cells divide
Read and Discuss:
 Mutations occur all the time in every cell in
the body. Each cell, however, has the
remarkable ability to recognize mistakes
and fix them before it passes them along to
its descendants. But a cell's DNA repair
mechanisms can fail, or be overwhelmed, or
become less efficient with age. Over time,
mistakes can accumulate.
Would You Want to Know?
 Would you want to know if you or your
children had a strong likelihood of getting
certain types of cancer or genetic disorders?
 Explain why or why not?
Sickle Cell
 What if the recessive gene in
your imaginary family of four
were a gene for sickle cell
 How many of these offspring
would have the disease?
 How many would be protected
against malaria?
Sickle Cell
 How can a mutation be harmful in one
environment and helpful in another?
 Why should a mutation persist if it kills
 Why are there more people with sickle cell
disease in one part of the world than in
other parts?
Index Card Activity
 Each card represent a gene for an unknown
 You have an allele on each card.
 What would the genotype for this trait be
 Each of you is heterozygous for this trait
because you have one dominant and one
recessive gene.
Pair Up Randomly
 Pair up with someone in your group.
 Hold your gene cards behind your
back, shuffle them, count to three, and
then put one card in front of you.
 Your alleles together become the
 Write down the genotype of this
 Repeat three more times to determine
the probability for four children
 How many of your children will have a
recessive genetic disorder?
Tay-Sachs Disease: fatal genetic disorder that
causes progressive destruction of the brain in young
One Wrong Letter
Tay-Sachs Disease
 Assume that the "a" allele in your gene
cards was a gene for Tay-Sachs disease.
How many of your offspring would have
the disease?
Mutation of Genes - Cancer
 Geneticists have learned that a mutation in
two specific genes have been linked to a
high risk of breast and ovarian cancer.
 These genes are called BRCA1 and
BRCA2, short for breast cancer 1 and breast
cancer 2
 They can do testing to find out if you carry
the mutated genes
Gene Mutation
 What happens if you receive a mutated
 According to the previous slide, could your
body fix the mutated gene?
 Would you want to know if you carried a
mutated cancer gene?
What happens next? (Slideshow)
What is Cancer? Animation Video
Cancer – Good Cells Gone Bad
 Baggies
Normal Cells and What the Items Represent
Cancer Cells and What the Items Represent
 Discuss with your group the different items
in the bag.
Be able to talk about one of the items if called
Textbook – Page 403
 Read the section on Lung Cancer
So.........Is Cancer Genetic?
 Some types are genetic.
 The most common are:
Breast Cancer
Ovarian Cancer
Prostate Cancer
Colorectal Cancer
Cancer Facts: How Does Lung
Cancer Develop Video
DNA – So What is It?
Extracting DNA
 Directions:
 Video:

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