Genetic engineering PP.ppt

deadstructureBiotechnology

Dec 14, 2012 (4 years and 8 months ago)

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BIOTECHNOLOGY

Chapter 13

Selective Breeding


Done for thousands of years


“Farmer Brown”


Produce desirable traits



“mother nature” to alter


genes


Requires time


1.
Inbreeding

-

Crossing similar


genotypes



Closely related


Maintains desirable traits


Produces undesirable traits


Done with horses, dogs, cattle,
plants


Golden Retriever Puppies

If inbreed incorrectly may have
problems with hip dysplasia, ears,
eyes….

2.
Hybridization
-

Crossing


different genotypes


Combines desirable traits of
both parents


“hybrid vigor”
-

healthier


offspring


Offspring usually sterile


Horses + donkeys = mule

Sweet & Hardy Corn

Most crop plants have been hybridized
for certain traits.

Traits like : more vitamins, certain
colors/flavors, larger, won’t freeze…

3.

Mutations


Are changes in DNA



Ultimate source of variation
!



Occur unexpected & randomly



Scientists speed up mutations by
exposing organisms to chemicals
or radiation


Radiated to produce small or no
seeds


Seedless Oranges


Drawback


loose flavor

Genetic Engineering

growing field of careers


Technique used to identify
and/or alter genes at the
molecular

level


Faster method


Requires equipment, money

Genetic engineering

1.
DNA fingerprinting by gel
electrophoresis

2.
PCR amplifies DNA

3.
Transformation of DNA


Transgenic organisms


GMO foods


Cloning

DNA fingerprinting



An identification system for
individuals



A unique pattern of bands that
represent segments of a person’s
DNA


The process is known as
gel
electrophoresis




DNA is cut into segments with
restriction enzymes



DNA is poured into agarose gel and
electric current is added



DNA segments travel across gel
and appear as bands when dye is
added


How does it work ? ? ?

How they are used


Scientists look for matching bands






1.
Comparisons with crime scene sample
can ID individuals as guilty or innocent

2.
Paternity testing



Suspect #1


Suspect #2


Crime scene evidence

Who is the father?......

Child

F1

F2

F3

F4

Cell Transformation


DNA from one organism is
taken into another (
sometimes
unrelated
) organism


Tools required:


1.
Restriction enzymes

to cut
DNA at specific sites

2.
Vectors
-

“DNA taxis” to
move the gene

( virus or plasmids)

Restriction Enzymes



Recognize DNA
palindromes


ex: RACECAR



Cut at specific sites

How Restriction Enzymes
Work

Plasmid Vectors


Small circular pieces of


bacterial DNA


Sections of DNA can be:



removed



manipulated


reinserted by “gluing” back into
DNA using the base pairing
rule!

Plasmid Vectors

Producing a Trangenic
Organism

Applications of DNA
Technology


Transgenic bacteria




“Ice minus” gene, nitrogen fixing
gene


“oil eaters”


HGH, insulin, interferon


Transgenic plants





resistant to herbicides



produce own pesticide



more protein



prevent rotting



more nutritious

Broccoflower and
Purple Cauliflower

Aggie Beta
-
sweet
Carrot


Transgenic animals





cows with more milk



goats, pigs, cows with human
proteins


cow milk with missing enzymes


cloning



+

=

“silk milk” = light


weight


with


steel


strength

Cloning


Donated egg has nucleus removed


Fertilized using electricity with a
diploid body cell


Implanted into surrogate mother to
grow and develop


History of Cloning

>>click on diagram to connect to internet

Gene Therapy


changing a gene that causes a
genetic disorder


The bad gene is replaced with
a working gene that makes the
needed protein


Ex: Cystic Fibrosis inhalers


Homework


Read the article on


page 330


Write answers to


#1 & #2