Transcript Selective Breeding - Hicksville Public Schools

Aim: How does genetic engineering
compare and contrast to selective
breeding?
The Selective Breeding Game:
Women’s Traits
Men’s Traits
What would you expect their offspring
to look like?
Selective Breeding/
Artificial Selection
What is Breeding?
To produce offspring
What is meant by being
Selective?
What music
do you like?
The power to choose or
pick out from among others.
Can you now define Selective
Breeding?
The process of choosing a few
organisms with desirable traits to
serve as the parents of the next
generation.
Types of Selective Breeding:
Hybridization/Crossbreeding: is the
process of crossing dissimilar
individuals to bring together the best of
both organisms.
+
Real Example of Hybridization:
+
Horse
Big, Fast,
Excitable
=
Hybrid
Donkey
Mule
Small, Slow, Strong,Calm
Calm
Endurance,
The hybrid is often stronger and hardier
than its parents: Hybrid Vigor
Real Example of Hybridization:
Burbank’s hybrid crosses
combined the disease
resistance of one plant
with the food-producing
capacity of another.
1872 - American horticulturist Luther Burbank
(1849-1926) developed a special potato.
Burbank, while trying to improve the Irish potato,
developed a hybrid that was more disease
resistant. He introduced the Burbank potato to
Ireland to help combat the blight epidemic.
Types of Selective Breeding:
Inbreeding: is the continued breeding
of organisms with similar characteristics
Breeders try to maintain
certain characteristics.
Inbreeding:
Advantages:
- desirable traits, like resistance to
disease or strength of an organism,
are collected.
Disadvantages:
-recessive disorders tend to increase.
Risks of Inbreeding:
What is a Recessive Disorder?
An inherited disorder
that occurs when the
offspring receives
a “bad” gene from
each parent.
1 out of 27 Jews are Tay-Sachs Disease
carriers for this disease.
Chromosome pair 15
Types of Selective Breeding:
Mass Selection: is choosing the best
plants and animals from a large
number for further breeding.
What are some benefits
of selective breeding?
1)Produce crops resistant to
disease.
2)Produce crops that are
bigger
3)Produce animals that
have less fat.
4)Seedless fruit!!!
Genetic Engineering vs. Selective
Breeding:
Selective Breeding
utilizes Natural
Genetic engineering
requires the altering of reproduction to
get desired
genes to get desired
characteristics.
characteristics.
Causes of Genetic Disease:
N = normal gene (Dominant)
n = disease causing gene
(Recessive)
Individuals carry two genes
for the same trait (alleles).
We get one gene from our
mom and one gene from dad.
Gene
Genetic Defects:
NN = This individual has two copies of
the normal gene and the offspring will
be OK.
Nn = This individual has one good gene
and one bad gene. This individual is
OK, but it is possible that offspring could
be affected.
nn = Person has the disease.
Genetic Defects:
Nn + Nn
Offspring
nn is possible
25% chance of
disease, 50% carrier
Ex: Tay-Sachs Disease
This is a genetic disease that mainly
affects Jewish people of Eastern
European descent. 1 out of 27 Jews
are carriers for this disease.