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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
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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.
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 Two
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types:
Gene Mutations
Chromosomal Mutations
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Result from changes in
a single gene.
Point mutation
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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:
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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.
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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