Genetic Engineering Notes - TeacherWeb

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

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Genetic Engineering Notes

Means of Genetic Manipulation

Selective Breeding

Hybridization

Inbreeding

Breeding of
dissimilar (not the
same) individuals

Breeding of
similar individuals

Includes

Selective Breeding

Humans use selective breeding, which takes
advantage of naturally occurring genetic
variation


in plants, animals, and other
organisms
,
to pass desired
traits

on to the
next generation






Can you think of some




desirable traits?

Means of Genetic Manipulation

What does it mean to manipulate?

Hybrids
-

usually sterile

Lion + Tiger =
LIGER

Horse + Donkey =
MULE

Donkey + Zebra =
Zeedonk

Beefalo or cattalo
: American bison and cow

Cama
: camel and llama

Grolar or pizzly
: grizzly bear and polar bear

Leopon
: leopard and lion

Liger
: male lion and female tiger

Mule
: male donkey and female horse

Tigon
: male tiger and female lion

Wolphin
: false killer whale and a dolphin

Yakalo
: yak and buffalo

Zeedonk
: zebra and donkey

Zorse
: zebra and horse


Can you find where this family is inbreeding?


Inbreeding


Inbreeding

-

“Hapsburg Lip”, a severely elongated lower
jaw and drooped lip that was a common
recessive trait of all Hapsburgs across
Europe.


-

In Charles II’s case, his head was so
misshapen that he was unable to chew at all
because his top and bottom teeth did not
meet.

Increasing Variation

What is Variation?

Increasing Variation

Increasing Variation

Mutation

Polyploidy

Use of radiation or
chemicals to alter
DNA

Use of drugs to
interfere with the
process of meiosis

Includes

Mutation

Polyploidy

Poly = Many

ploidy = sets of chromosomes

Poly + ploidy = many sets of chromosomes


Triploid

Genetic Engineering

Genetic Engineering

Transformation

Cloning

A cell takes in DNA
from outside the
cell

Use of a single adult
cell to produce a
genetically identical
individual

Includes

Transformation

Bacterium

Plasmid

Free DNA

Transformed

Bacterium

Plasmid
+ DNA

Cloning


Cloning

Normal Sheep cells

Genetic Engineering


making changes
in the
DNA code

DNA Manipulation
:

1. Cells are opened and the DNA is
separated

from other cell parts (DNA extraction
-

remember the strawberries!)

2. Biologists cut the DNA into smaller


fragments using
restriction enzymes


which cut the DNA at a specific sequence of
nucleotides


Gel Electrophoresis

3. Using
gel electrophoresis
, a mixture of DNA
fragments is placed at one end of a porous
gel. When electric voltage is applied, DNA
(
negatively

charged) move toward the positive
end of the gel. The smaller the DNA fragment,
the
faster

and
farther

it moves!

Gel Electrophoresis Animation


http://www.sumanasinc.com/webcontent/anim
ations/content/gelelectrophoresis.html

(narrated)

DNA fingerprinting


Used to identify a child’s biological father


Examine the bands in the diagram of a gel
electrophoresis


Each band represents a fragment of DNA


DNA fingerprinting

Can you determine

who the father is?

CSI: Who is the Dad?

Can you determine

who the father is?


Cell Transformation
-

Transforming
Bacteria (recombinant DNA)

During
transformation
, a cell takes in DNA from
outside the cell. This external DNA becomes a
component of the cell’s DNA.

Free DNA

Transformed

Bacterium

Plasmid
+ DNA

Bacterium

Plasmid

Cell Transformation

In bacteria, the circular DNA molecule is known
as a
plasmid
.

Plasmid DNA has two essential features:


1. Its DNA sequence helps promote plasmid
replication
.


2. If the plasmid containing the foreign DNA
manages to get inside a
bacterial

cell, this
sequence ensures that it will be
replicated
.

Why is Transforming Bacteria
Important?

When organisms contains genes from another
species, they are called
transgenic
.

Transgenic bacteria now produce important
substances useful for
health

and industry.

These transformed bacteria produce proteins
cheaply,
quickly
, and abundantly.

Examples are human insulin for people with
diabetes
, growth hormones and clotting
factor for people with
hemophilia
.

Examples of Other Transgenic
Organisms:

Transgenic Anima
ls
-

laboratory mice have been
produced with human genes to that their
immune systems are similar to humans. This
way scientists can study human
diseases

by
using mice. Some livestock have extra copies
of growth hormone genes which allows them
to grow
faster

and have
leaner

meat.

Examples of Other Transgenic
Organisms:

Transgenic Plants
-

also called
genetically

modified
(GM)

Plants can contain genes that produce a natural
insecticide

so that plants do not have to be
sprayed.

In the future, plants could produced human
antibodies

to help fight diseases.

Examples of Other Transgenic
Organisms:

A rice plant has been developed to contain
vitamin
A
, a nutrient that is essential for our
health. Rice is a major food source for
billions

of the world’s population

Cloning

A
clone

is a member of a population of
genetically
identical

cells produced from a
single
cell
.

Researchers hope that cloning will enable them
to make copies of
transgenic

animals to help
save
endangered

species.


Normal Sheep cells

Cloning

This technology is controversial because some
studies suggest that cloned animals may suffer
from genetic
defects

and health
problems
.

Cloning in humans raises serious ethical and
moral

issues.

http://player.discoveryeducation.com/index.
cfm?guidAssetId=f91a792d
-
3f8f
-
4092
-
9540
-
58f60000b1df&productCode=HUB


Gene Therapy

Gene Therapy
-

an absent or
faulty

gene is
replaced with a normal,
working

gene.


Gene Therapy

In gene therapy,
viruses

are often used because
they have the ability to enter a cell’s DNA.

The virus particles are modified so that they
cannot cause
disease
. Then, a DNA fragment
containing a replacement gene is
spliced

to
the viral DNA.

Virus

Gene Therapy

The patient is then infected with the modified
virus particles, which should carry the gene
into
cells

to correct the genetic defects.

Unfortunately, these experiments have not been
very successful.

Gene therapy remains a
high
-
risk
, experimental
procedure.


Identifying Structures

Use the following words
:

-
bone marrow cell

-
genetically engineered virus

-
bone marrow

-
normal hemoglobin gene

Identifying Structures

4. Normal hemoglobin gene

5. Genetically engineered virus

6. Bone marrow cell

7. Bone marrow