Genetic Engineering.pptx - RelyonBiology

Genetic Engineering

Genetic Engineering:

•
Genetic Engineering: process of altering
biological systems by the purposeful
manipulation of DNA

•
Applications:

–
Production of proteins (insulin, hormones,
vaccine)

–
Agriculture: plants can be more suitable for
growth and resistant to insects and bacteria

–
Medicine: diagnosis, medication, gene
replacement therapy

Methods:

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Breeding

•
Investigation (Genetic testing for disease, test
paternity, investigating crime scenes)

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Cloning (genes of interest, plants/animals)


Breeding


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Breeding Methods: are used to get desirable
traits

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Selective breeding: choosing an organism with
desirable traits

–
Inbreeding: mating closely related organisms that
have desired traits

•
Decreases variation

–
Hybridization: mating organisms that are not
closely related for a mixture of both genes

Hybrids usually are sterile!

Test Cross Activity

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Test cross is one way to determine genotype

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HH or Hh? Cross it with a hh and observe
offspring

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If any express the recessive trait hh then the
parent was Hh

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Pg:347

•
Read

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Critical Thinking #1
-
5


Gene Cloning

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Why?

•

Some people lack the essential proteins like
insulin, thyroxine, etc

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Create organisms that have characteristics of
other organism

How to clone genes?

1.
Identify gene of interest

2.
Cut it out using a
restriction enzyme

•
Restriction enzyme
recognizes a specific DNA nucleotide
sequence and cuts at that site

3.
Cut a vector (usually a plasmid (circular DNA) of a
bacteria)

4.
Insert cut gene of interest into vector using sticky
ends (called splicing)

5.
Insert the plasmid back into the host (bacteria)

–
This technique is called
Recombinant DNA
to create a
transgenic organism
(organism that contains foreign
genes)


Diagram of Cleavage

GAATTC

CTTAAG

GAATTC

CTTAAG

G AATTC

CTTAA G

Diagram of Recombinant DNA

Activity in Text Book

•
Mini Lab 13
-
1 on pg 351

•
Follow all steps in procedure

•
Answer analysis question #3


Gel Electrophoresis

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Gel Electrophoresis: separates molecules
based on their rate of movement through a
gel under the influence of an electric field,
based on the size and charge of the molecules

How does Gel Electrophoresis work?

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DNA fragments are made using restriction
enzymes

•
A mixture of fragments is placed in one end of
the gel

•
An electric voltage is applied to the gel

•
DNA (which is negative) would move to the
positive

•
Since there are tiny holes in the gel, the small
pieces move farther in the gel

•
This creates a unique DNA “fingerprint”


What can this be used for?

•
Since each person has a unique sequence of
DNA, the restriction enzyme creates different
size pieces for each persons DNA called a DNA
fingerprint

•
Related people have similar DNA and
therefore their DNA will be cut into similar size
pieces

•
It can be used to determine paternity and help
identify unknown DNA samples

Gel Electrophoresis

Activity in the textbook

•
Activity 13
-
3 Questions 1
-
3

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Pg 361



PCR


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Is the technique that allows us to make many
copies of genes.

•
First lets review some concepts….

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How does DNA replicate in cells? Steps?

–
DNA unwinds and unzips

–
Free nucleotides attach to their complementary
bases

–
DNA polymerase attaches them together

Steps in PCR: Machine assisted DNA
replication

•
PCR stands for polymerase chain reaction

•
DNA of interest is placed in machine

•
DNA is heated

–
Heat will break the weak hydrogen bond btw the strands

•
Free nucleotides are added

•
DNA polymerase is added creating the new
complementary strands

•
Steps are repeated to create a large amount of DNA

•
Does your DNA polymerase work at high
temperatures? The DNA polymerase used is called taq
polymerase…. From bacteria that live in hot springs..

Cloning an organism…… OH DOLLY!

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Steps:

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Donor cell is taken from a sheep

–
An egg cell from a different sheep is taken

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The nucleus is extracted

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The empty egg is fused with the donor cell

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The cell is implanted into a female sheep

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Will eventually become a clone of the donor

Cloning an organism

Challenge question…

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Would a clone have more mutations than a
normal offspring?

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Would a clone have the same survival rate as a
normal offspring?

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What are some dangers of this new
technology?

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Should the government put restrictions on
human cloning?

HW


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Questions 1
-
20

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Pg 365
-
366

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WRITE QUESTION AND ANSWER…..