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Modern Genetics
Human inheritance
Some traits are formed from single genes
(2 alleles)
 Some are formed from multiple genes
(multiple alleles)

Example: blood type

Blood types
Types:
A, B, AB, O
3 alleles control the blood type
A & B are co dominant
O is recessive
SexChromosomes
Carry
genes that determine if a person is
male or female
Each parent offers 2 alleles
Male X, Y
Female X, X
Alleles on the X and Y chromosome are
not the same
Sex Linked Genes
Genes carried on the sex chromosomes
 A female has 2 X chromosomes: if one x
has a dominant gene and the other has a
recessive, the dominant trait will show
 In a male, there isn't corresponding
alleles. If the X chromosome has a
recessive trait, and there is no
corresponding allele on the Y chromosome,
then the recessive trait will show.
 Therefore, males have a higher tendency
to show recessive sex linked traits.

Carriers
A heterozygous person
 Because they have the dominant allele, the
recessive trait doesn't show, but they can
still pass it along to offspring

Genetic Disorders
Def:
an abnormal condition inherited
through chromosomes
Some are caused by mutations
Some caused by an change in
chromosome number
Cystic
fibrosis
Sickle cell
Hemophilia
Down syndrome
Pedigree

Chart that tracks which family members
have a certain trait
Managing Disorders
Karyotype: picture of the chromosomes in
a cell--can determine if a mutation or extra
chromosome is present
 Genetic counseling: to help coping with
disorders
 Therapy: to assist with disorders

Modern Genetics
Selective Breeding: is the
process of selecting and
breeding parent organisms to
pass on particular traits to the
offspring.
Examples:
Horses, pigs, corn, dogs
Question:
What do you thing the animal
to the left is? It has been
selectively bred.
Modern Genetics
Cross Breeding: A
cross between two pure
breed parents creating a
hybrid.
Killer Bees: a cross
between Brazilian bees
with African bees to
create a bee that would
produce more honey.
Modern Genetics
Genetic Engineering: is the process
in which a sequence of DNA from an
organism is first isolated, then
inserted into the DNA of another
organism, changing that organism’s
DNA.
Example:
Taking genes from microorganism and
inserting them into plants to produce
a natural insect killing chemical.
Inserting a bioluminescent gene into
bacteria to make it glow.
Modern Genetics
Genetic Engineering vs. Organic
Most of you have eaten genetic
engineered/ modified foods.
Many plants have bacterial
genes that make them more
resistant to insects.
How many of you have eaten
fruits without seeds?
Picture:
Here is a tobacco plant that
glows.
Modern Genetics
Cloning: is a technique that
uses technology to make
copies. It can be applied to a
segment of DNA or the whole
organism.
Examples:
Bacteria: create human insulin
which is used to help people
with diabetes.
A sheep named Dolly.
(Nucleus Transfer)
Modern Genetics
Cloning a Gene
Modern Genetics
Genome: is all the genetic material in an
organism.
Modern Genetics
So why clone?
Medicine
2. Reviving endangered or extinct animals:
Jurassic Park!
3. Reproducing a deceased pet
4. Cloning humans
1.
Modern Genetics
DNA Identification: The
use of DNA to identify a
person.
DNA Fingerprinting: Chart
representing repeating base
pairs
Example:
Used in crime solving
A fun case at NOVA.
DNA Evidence Video
Modern Genetics
What are Some Issues to Cloning?
The Good vs. Bad
What are the ethical issues?
Modern Genetics
There are genetically engineered salmon that
grow faster. They are breed in captivity,
near rivers and stream. What might happen
if they escape?
Modern Genetics
Should we label genetically modified foods?
Many companies already label food and
products that have been genetically altered.