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Mutations & Genetic Engineering
Indicator B – 4.8:
Compare the consequences of mutations in body cells
with those in gametes.
Indicator B – 4.9:
Exemplify ways that introduce new genetic
characteristics into an organism or a population by
applying the principles of modern genetics.
 Mutation:

mutagen, mutant cell, gene mutation,
chromosomal mutation, nondisjunction
 Beneficial
mutations
 Pedigree
 Genetic

Engineering:
gene map, genome, cloning, gene therapy, stem
cells
 Selective

Breeding:
Inbreeding, hybridization
Students have no previous knowledge of this
concept. It has not been addressed in previous
grades.
A mutation is an alteration of an organism’s DNA and
can range in severity.
 Most mutations are automatically repaired by the
organism’s enzymes, but those that are not repaired
may result in altered chromosomes or genes.
 Mutant body cells are not passed on to offspring but
mutant gametes may be inherited.
 In some cases, mutations are beneficial to organisms.
 A pedigree is a chart constructed to show an inheritance
pattern within a family through multiple generations.
 Genetic engineering is the process of replacing specific
genes in an organism in order to ensure that the organism
expresses a desired trait.
 Cloning, gene therapy, and hybridization are applications of
genetic engineering.
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Compare the consequences of mutations in body cells with those in
gametes.
Recall the causes of mutations.
Classify mutations as resulting from sex cell or somatic cell alterations.
Classify mutations as genetic or chromosomal.
Exemplify genetic or chromosomal disorders.
Interpret a pedigree with regard to the nature of specific traits
within a family.
Exemplify ways that introduce new genetic characteristics into
an organism or a population.
Recognize types of genetic engineering and selective breeding.
Summarize the purposes of the various types of genetic
engineering and selective breeding.
Compare selective breeding and hybridization.
Summarize the benefits & drawbacks of the types of genetic
engineering & selective breeding.
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Mutation
Point mutation
Frameshift mutation
Mutagen
Clone
Genetic engineering
Recombinant DNA
Transgenic
Genomics
Human Genome Project
Gene therapy
Artificial selection (selective breeding)
A mutation is any change in the DNA
sequence that causes a change in the amino
acid sequence, thus a variation in the
protein.
 Mutations



can occur many ways:
They can be inherited from the parent(s).
They can occur in an egg or sperm cell just after
fertilization.
They can be acquired during the organism’s
lifetime.
Egg
Sperm
Mutation Occurs
Fertilized Egg
Body Cells of Offspring
Mutation
 Mutations
in Gametes
Can be passed on to
offspring.
 May result in poorly formed
or nonfunctional
proteins.
 May be lethal.

 Mutations
in Somatic
Cells
Not passed on to
offspring.
 Can interfere with cell
function.
 Due to mitosis, the
mutation will be passed
on to other cells.

 Two


types:
Gene Mutations
Chromosomal Mutations


Result from changes in
a single gene.
Point mutation


Occur at a single point.
A nucleotide can be
substituted for another
and can change the
entire sequence of
amino acids therefore
messing with the
protein.
Normal Reading Frame:
THE FLY HAD ONE RED EYE
Point Mutation on Reading Frame:
THE FLY HID ONE RED EYE
Remember: DNARNAAmino Acidsproteins.
 Due
to a point mutation in the Beta Globin
gene.
 DNA
should be C T C but is actually C A C.
 RNA should be G A G but is actually G U G.
 This change causes a change in the amino acid.
Normal hemoglobin & RBC
Sickled hemoglobin & RBC

Frame-shift
Mutation
Involves deletions
and insertions of
nucleotides.
 Can change the
entire reading frame
of the codon, thus
causing problems
with the protein.

Normal Reading Frame:
THE FLY HAD ONE RED EYE
Insertion:
THE FLY QHA DON ERE DEY
Deletion:
THE FLH ADO NER EDE YE
Remember DNARNAAmino Acidsproteins.
video segment
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Involves changes in the number or
structure of chromosomes.
May change the locations of genes on the
chromosomes and even the number of
copies of some.
Four types:




Deletion
Duplication
Inversion
Translocation
May lead to
genetic
disorders
 There
are many different chromosomal
mutation disorders. The following slides
highlight just a few of these. They do contain
images that may be hard for some students
to view, so please view them with caution.
Down Syndrome is the most recognizable
of these, but there are others.


http://medgen.genetics.utah.edu/photographs/pages/trisomy_13.htm
http://www.plasticsurgery4u.com/klinefelters_xxy/index.html
Turner Syndrome
Cri du Chat Syndrome
http://www.genome.gov/19519119
http://www.genome.gov/19517558
 Polyploidy
usually leads to death in
animals.
 Some plants are successful with extra
set(s) of chromosomes.
http://waynesword.palomar.edu/hybrids1.htm#watermelon
In some cases mutations
are beneficial to
organisms. Beneficial
mutations are changes
that may be useful to
organisms in different
changing environments.
These mutations result
in phenotypes that are
favored by natural
selection and increase
in population.
Antibiotic resistant bacteria is an
example of a beneficial mutation-at
least from the point of view from the
bacteria.
 Mutations
 By
can lead to genetic disorders.
examining a pedigree, geneticists can also
see the likelihood of an individual inheriting
a genetic disorder.
A pedigree is a chart
constructed to show an
inheritance pattern
within a family through
multiple generations.
Through the use of a
pedigree chart and key,
the genotype and
phenotype of the family
members and the
genetic characteristic
can be tracked.
Unaffected
Female
Unaffected Male
Mating
Unaffected male Offspring
Affected female
Offspring
offspring
Changes are possible that will NOT lead to a
change in the protein…not a mutation.
 Mutations occur about 1/100 000 000 bases.

 Wobble
position: 3rd base in codon provides
protection against mutation.
 Ex: CCA, CCG, CCC, CCU = proline
 DNA has proofreading enzymes that can repair
mismatches before transcription.
The role of DNA polymerase is to proofread a
frame before it is ready to be translated.
Often, this enzyme can catch a mutation
before it goes through translation, but not
always. If the mutation is caught and
correct, the organism will never be affected.
However, if it doesn’t then the organism will
be affected.
 Mutagens
are factors such as radiation,
chemicals, ultraviolet light, etc. that can
cause changes in DNA. Some are natural,
others are not.
Check out some mutagens....and what they do!
Mutagens
Since ALL living things use DNA as their genetic
material, it is possible to insert DNA from one species
to another, either through a cross if the organisms are
of the same species, or through recombinant DNA if the
organisms are dissimilar.

Scientists are now able to
manipulate, or handle and
change, DNA within organisms.

They are able to examine DNA
on an entirely new level
because of increases in
technology.

They are able to change DNA
or extract DNA from one
organism and place it in
another. However, this is not
always successful.
 Genetic
engineering
the process of
replacing specific
genes in an organism
in order to ensure
that the organism
expresses a desired
trait.

Accomplished by taking
specific genes from one
organism and placing
them into another
organism.
Genetic engineering occurs when scientists know
exactly where genes occur on chromosomes. A gene
map shows this.
 Genome
refers to all
the genetic material
in an organism.
 The
Human Genome
Project that mapped
the DNA sequence of
human genes is useful
in identifying genes
for specific traits.
In cloning, an identical copy of a gene or an
entire organism is produced. Cloning brings
benefits but may also result in genetic disorders
or health problems.
In gene therapy, scientists insert normal genes into
absent or abnormal genes. Once inserted, the normal
gene begins to produce the correct protein or enzyme,
eliminating the cause of the disorder. However, gene
therapy has had limited success because the hose often
rejects the injected genetic material.
 Plants
that make natural insecticides, are higher
in protein, or spoil more slowly.
 Animals that are bigger, are faster growing, or are
resistant to disease.
 Bacteria that produce hormones such as human
insulin or human growth hormones.
 In humans, it is theoretically possible to insert
copies of normal genes into the cells of people
with different genetic disorders.
 Why
would you want to selectively breed an
organism?
 How
is selective breeding done?
 What
are some organisms that are often
products of selective breeding?
 Selective
breeding is the
method of artificially
selecting and breeding
only organisms with a
desired trait to produce
the next generation.
Almost all domesticated
animals and most crops
have been selectively
bred.
Pug
Beagle
Canis familiaris
Canis familiaris
***What would have
to be done to make
the puggle a breed?
Canis familiaris
Puggle
***What evidence
would we have that a
new breed had been
created?

In order to keep lines of
breeds pure, breeders
will often interbreed
their organism, called
inbreeding. While the line
will stay pure, it may also
result in many genetic
disorders and problems.
The drawback being
recessive gene defects
often show up.
Tiger + Lion = Liger
Panthera tigris x Panthera leo
Top 10 Animal Hybrids
http://members.diaryland.com/edit/adclick.phtml?a=709142448
http://www.eriksaunders.com/archive.FEB05.htm
They say that the closest relative of humans
is the chimpanzee. Would a hybrid be possible?
K:
P:
C:
O:
F:
G:
S:
Animalia
Chordata
Mammalia
Primates
Homindae
Pan
troglodytes
K:
P:
C:
O:
F:
G:
S:
Animalia
Chordata
Mammalia
Primates
Homindae
?
?
K:
P:
C:
O:
F:
G:
S:
Animalia
Chordata
Mammalia
Primates
Hominidae
Homo
sapiens
http://www.primarilyprimates.org/videos/index.html
 Faster
than selective breeding.
 Only 1 generation needed.
 More predictable results than selective
breeding.
 Can transfer traits from species that are
completely unrelated.
These fluorescent Zebrafish contain DNA of a
sea anemone to cause their glow.
Corn earworms frequently destroy corn crops.
GM Corn can be made to produce a protein
that kills these insects—corn that makes its
own pesticide.
GM chickens in Israel can be grown
featherless, but more meaty—a benefit to
farmers.
GOOD: can increase world food supply—can make farming easier
BAD: can aggravate food allergies—too much use of antibiotics—
risk of pesticide resistance
“ORGANIC”
food products that have not had any genetic modification.
Are organic foods healthier?
Should they cost more?
Is there any danger posed by eating GM foods?
Should food labels indicate the GM of the food
products?
Guess What’s for Dinner!!