What is DNA?

lessfrustratedBiotechnology

Oct 23, 2013 (3 years and 7 months ago)

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Biotechnology

Chapter 13


pages 360
-

379

Can
we

modify the
genetic code of living
things? (& should we?)

Means of Genetic Manipulation


Selective breeding


Of dissimilar individuals, called
hybridization


Of similar individuals, called
inbreeding


Increasing genetic variation


Mutation

caused by mutagen (radiation or
chemicals)


Use of drugs to produce
polyploids



Genetic Engineering!!!
(direct manipulation of an organism’s genes)

Genetic Engineering

Also known as…


Genetic modification or
manipulation


Recombinant DNA
technology


Gene splicing

Genetic Engineering

Uses two main techniques or
processes:

1.
Gene
cloning
(makes copies)

2.
Transformation
(take up new
DNA)



Tools of genetic engineering


Restriction enzymes
cut DNA at
a specific place in the
sequence


Gene splicing
recombines DNA
from different sources


Vectors

&

plasmids

harvest
DNA for cloning

How’s it done?

As easy as 1, 2, 3…


Rabbit DNA

+

Crab DNA

=

Crabbit !!

How to genetically engineer DNA

1.
Begin with the source DNA you want

2.
Cut out a DNA fragment from the
source DNA with
restriction enzyme

3.
Cut out a sequence from the
plasmid

with the
same

restriction enzyme

4.
The source DNA is inserted into
plasmid


How to genetically engineer DNA

5.
Bacteria have to take up the
foreign DNA. This is called
transformation
.

6.
Bacteria becomes a
cloning
vector
, making copies of
recombinant DNA

Applications


Genetic screening
identifies
“broken” DNA


Gene therapy
uses
recombinant DNA technology
to replace an absent or faulty
gene with a normal, working
gene

(




1)
Try your hand at gene therapy


click here
)

Applications


Gene splicing
uses
recombinant DNA technology
to produce
transgenic

organisms

(organisms with
other organisms’ genes) that
help make better medicines,
treatments, and supplements
(Example: Transgenic Corn from our
‘Virtual Corn Lab’ 1
st

Qtr.!)



Polymerase Chain Reaction
(PCR)
copies DNA


Gel Electrophoresis
makes a
picture of DNA called a DNA
fingerprint

Other

Tools
of
Genetic
Engineering:



How to make a DNA fingerprint

1.
Small amounts of DNA are extracted
from blood, saliva, hair, urine, etc
(


-

2)
Click here for Virtual DNA extraction Lab
)

2.
If the amount of DNA is too small, the
polymerase chain reaction, or PCR,
can be used to increase the quantity
of DNA
(


-

3)

Click here for Virtual PCR lab
)

How to make a DNA fingerprint

3.
DNA is cut into fragments of specific
sizes by restriction enzymes

4.
DNA is put in a slab of gel and an
electrical current moves DNA to the +
electrode
(


-

4)
Click here for Virtual Gel Electrophoresis lab
)


Bigger pieces move more slowly &
travel shorter distances

How to make a DNA fingerprint

5.
The banding pattern in the gel is
analyzed

Applications


DNA fingerprinting
identifies
differences between
individuals’ genetic makeup to
establish identity or
relationships


Stem cells
have the ability to
develop into different cell types


What is a stem cell?

(


-

5)
Click here for helpful
animation
)


Types of stem cells

(


-

6)
Click here for helpful animation
)


Embryonic stem cells

(




7)
Click here for helpful
animation
)


Somatic
cell nuclear transfer

(




8)
Click here for Virtual Cloning
Lab
)




T
ools
of genetic
engineering

Applications


Cloning DNA

enables rapid,
large
-
scale
production of
useful genes,
cells, tissues

Watch Nova
science Now
: Stem Cells
(
click here
)

***WE WILL
VIEW THIS TOGETHER IN CLASS***

Problem…

How would you apply this
technique to make a vaccine?


Hint
:


How do vaccines work?


What does your immune system use to
target foreign cells?


Can your immune system be “tricked” into
thinking it is infected with a virus?

Is there a need for a cure?

Should “broken” genes be fixed?