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Genetic Engineering
Think of the possibilities
Video
https://www.youtube.com/watch?v=Ga8x1
-XdXiQ
Selective Breeding
Selective Breeding
Selective breeding allows only those
organisms with desired characteristics
to produce the next generation.
Nearly all domestic animals and most
crop plants have been produced by
selective breeding.
Example: Champion race horses,
cows with tender meat, large oranges
on a tree.
Selective Breeding
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Artificial selection- where individuals
with desirable traits are mated to
produce offspring with those traits.
Hybridization
Hybridization is the crossing of
dissimilar individuals to bring together
the best of both organisms.
Hybrids, the individuals produced by
such crosses, are often hardier than
either of the
parents.https://www.youtube.com/wat
ch?v=4VlTm47xnJE
Inbreeding
Inbreeding is the continued breeding
of individuals with similar
characteristics.
Inbreeding helps to ensure that the
characteristics that make each breed
unique will be preserved.
Serious genetic problems can result
from excessive inbreeding.
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WHY?
Inbreeding and Variation
Recessive genetic disorders can be
blindness, or joint deformities.
Variation is a term used to identify the
difference between individuals of a species.
For example: Some humans have blond
hair and some have brown. This is a
variation among humans.
Finches-
Increasing Variation
Why might breeders try to induce mutations?
Breeders increase the genetic variation in a
population by inducing mutations.
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Producing New Kinds of Bacteria
Introducing mutations has allowed scientists to
develop hundreds of useful bacterial strains,
including bacteria that can clean up oil spills.
Genetics Engineering
In genetic engineering, biologists make
changes in the DNA code of a living organism.
How do scientists make changes to DNA?
Scientists use different techniques to:
extract DNA from cells
cut DNA into smaller pieces
identify the sequence of bases in a DNA
molecule
make unlimited copies of DNA
The Tools of Molecular Biology
Each restriction enzyme cuts DNA at a specific
sequence of nucleotides.
How do scientists manipulate DNA
1. DNA is removed from
the cell of an
organism
2. DNA is cut using
restriction enzymes to
identify the bases.
3. There are thousands of
restriction enzymes,
each cuts the DNA at
a different starting
place based in the
nucleotide sequence.
4. DNA fragments are
separated by gel
electrophoresis.
5. Positive charged DNA
moves to negative poles
and negative DNA moves to
positive poles. Smaller
fragments move faster,
larger move slower.
6. This is also how DNA is Video clip
compared (ex at crime
scenes)
Video clip 2
7. Then, unlimited copies of
fragments are made by
scientist.
https://www.youtube.com/watch?v=3i-DxJ3oJzE
Nova: who done it
http://www.pbs.org/wgbh/nova/sheppard/analyze.html
http://www.dnalc.org/resources/animations/re
striction.html
Cell Transformation
13-3 Cell Transformation
Recombinant DNA
Host Cell DNA
Target gene
Modified Host Cell DNA
Cell Transformation
During transformation, a cell takes in DNA from
outside the cell. The external DNA becomes a
component of the cell's DNA.
Foreign DNA is first joined to a small, circular
DNA molecule known as a plasmid.
Plasmids are found naturally in some bacteria
and have been very useful for DNA transfer.
The plasmid has a genetic marker —a gene that
makes it possible to distinguish bacteria that
carry the plasmid (and the foreign DNA) from
those that don't.
Biotechnology and genetic engineering
Genetic engineering is making changes in the
DNA code of a living organism.
A scientist can take genes from one organism
and transfer them to another organism. This is
called transformation.
Genetic engineering has given rise to a new
technological field called biotechnology
(technology of life).
The organisms that have DNA transferred to
them are called transgenic.
(trans: means different, genic: refers to genes)
Transgenic helpful?
How are transgenic organisms useful to human
beings?
Transgenic bacteria produce important
substances useful for health and industry.
Transgenic bacteria have been used to produce:
 insulin
 growth hormone
 clotting factor
Recombinant
DNA
Gene for human
growth hormone
Gene for human
growth hormone
Human Cell
Bacterial
chromosome
Sticky
ends
DNA
recombination
DNA
insertion
Bacteria cell
Plasmid
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Prentice
Hall
Bacteria cell
containing gene for
human growth
hormone
..\Genetic engineering\1 gen mod insulin
wit res enz.wmv
http://www.youtube.com/watch?v=8rXizmL
jegI
Animals and plants
Transgenic animals: genes inserted into
animals so they produce what humans need.
A way to improve the food supply: livestock
given genes that make them grow faster or resist
bacteria that cause infections.
Mice are given human genes that make their
immune system work like ours. They can now
be used for researching the human immune
system
Transgenic Plants
Transgenic plants: plants are given genes
that make them produce a natural
pesticide. Now they don’t have to be
sprayed with cancer causing pesticides.
25% of all corn is like this. It called
genetically modified or GM.
Cloning
Cloning
A clone is a member of
a population of
genetically identical
cells produced from a
single cell.
In 1997, Ian Wilmut
cloned a sheep called
Dolly.
Dolly and Bonnie
Cloning
Donor Nucleus
Fused cell
Egg Cell
Embryo
Cloned
Lamb
Foster Mother
Cloning
1. A single cell is removed from a parent
organism.
2. An entire individual is grown from that
cell.
3. Remember one cell has all the DNA it
needs to make an entire organism.
4. Each cell in the body has the same DNA,
but cells vary because different genes
are turned on in each cell.
Dolly
Dolly was the first animal cloned.
She had the same exact DNA as
her mother and had no father.
Cloning is a form of asexual
reproduction.
Since Dolly, cats and other
organisms have been cloned.
The cat that was cloned had the
same exact DNA but different
color fur than the mother.
How can this be?
Environment plays a huge part
in the way organisms develop.
http://content.tutorvista.com/biology_11/content/media/cloning.swf
..\Genetic
engineering\Bonehead_Detectives_of_the
_Paleoworld__The_Dino_Clones.wmv
Cool cloning vids
http://videos.howstuffworks.com/discovery/38036-discovery-news-techhuman-cloning-video.htm
http://videos.howstuffworks.com/tlc/29324-understanding-cloning-a-cowvideo.htm
http://videos.howstuffworks.com/tlc/29134-understanding-savingendangered-species-with-cloning-video.htm
http://videos.howstuffworks.com/science-channel/39069-popscis-futureof-organ-factory-video.htm
Human Genome
Human Chromosomes
Human Chromosomes
Cell biologists analyze chromosomes by looking at
karyotypes.
Cells are photographed during mitosis. Scientists
then cut out the chromosomes from the
photographs and group them together in pairs.
A picture of chromosomes arranged in this way is
known as a karyotype.
Human Karyotype
Human Traits
Pedigree Charts
A pedigree chart shows the relationships within a
famliy.
Genetic counselors analyze pedigree charts to
infer the genotypes of family members.
Human Traits
A horizontal line
connecting a
male and a
female
represents a
marriage.
A shaded
circle or
square
indicates
that a person
expresses
the trait.
A circle
represents
a female.
A square
represents
a male.
A vertical line and a
bracket connect the
parents to their
children.
A circle or square
that is not shaded
indicates that a
person does not
express the trait.
Human Genes
Blood Group Genes
Human blood comes in a variety of genetically
determined blood groups.
A number of genes are responsible for human blood
groups.
Human Genes
Recessive Alleles
Many disorders are caused by autosomal recessive
alleles.
Human Genes
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Hall
From Gene to Molecule
Sickle Cell Disease
Sickle cell disease is a
common genetic disorder
found in African Americans.
It is characterized by the bent
and twisted shape of the
red blood cells.
Sex-Linked Genes
Sex-Linked Genes
The X chromosome and the Y chromosomes
determine sex.
Genes located on these chromosomes are called
sex-linked genes.
More than 100 sex-linked genetic disorders have
now been mapped to the X chromosome.
Sex-Linked Genes
The Y chromosome is
much smaller than the X
chromosome and appears
to contain only a few
genes.
Sex-Linked Genes
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For a recessive allele to be expressed in
females, there must be two copies of the
allele, one on each of the two X
chromosomes.
Males have just one X
chromosome. Thus, all X-linked
alleles are expressed in males,
even if they are recessive.
Chromosomal Disorders
The most common error in meiosis occurs when
homologous chromosomes fail to separate.
This is known as nondisjunction, which means,
“not coming apart.”
If nondisjunction occurs, abnormal numbers of
chromosomes may find their way into gametes, and
a disorder of chromosome numbers may result.
Chromosomal Disorders
Down syndrome
produces mild to
severe mental
retardation.
It is characterized
by:
increased
susceptibility to
many diseases
higher frequency of
some birth defects
Down Syndrome Karyotype
The Human Genome Project
A genome is all the DNA in one cell of an
organism.
The main goal of the Human Genome
Project was to identify the DNA sequence
of every gene in the human genome. It
was completed in May 2006.
Scientists estimate that human DNA has
around 25,000 genes.
Gene Therapy
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In gene therapy, an absent or faulty gene is
replaced by a normal, working gene.
The body can then make the correct protein or
enzyme, eliminating the cause of the disorder.
Gene Therapy
Viruses are often
used because of
their ability to enter a
cell’s DNA.
Virus particles are
modified so that they
cannot cause
disease.
Copyright Pearson Prentice
Hall
Gene Therapy
A DNA fragment containing a replacement
gene is spliced to viral DNA.
Copyright Pearson Prentice
Hall