#: ___ scientist’s name: _____________
Mutations
Comp 5c-2
5.Demonstrate an understanding of the molecular basis of heredity.
Discuss the characteristics & implications of both chromosomal & gene
mutations. (DOK 2)
Textbook: Chapter 12-4
DaBook: Section 12.4
Mutation:



a change in the ____________
It’s a mistake that’s made during ________ or __________
can be harmful:


helpful:
neutral:
if a mutation occurs in __________ or ____________, that mutation is passed onto
offspring.
if a mutation occurs in ___________, that mutation affects only the organism and is not
passed onto offspring.
Gene Mutations:


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
Change in __________________ caused by change in structure of the DNA
Gene mutations can be caused by DNA bases being:
When genes are added or removed, the mutation is called a ________

Adding or removing genes is called a
____________________.
_____________________ (red blood cells are
C-shaped so can't carry as much oxygen) is an
example of a gene mutation in African
Americans
 __________________ (a disorder where the
nervous system deteriorates) is a fatal gene
mutation in Jewish people of Central European Descent
__________________ OR PKU occurs from the inability of a gene to synthesize
a single enzyme necessary for the normal metabolism of phenylalanine and
results in death
Are usually harmful because a mistake in DNA is carried into mRNA & results in
many wrong...



Correct DNA: ATA
CCG
TGA
2
TAT
GGC
ACT
Correct mRNA: UAU
GGC
Correct amino acids: Tyrosine
ACU
Glycine
Threonine
Extra inserted base (G) shifts how we read the
codons (3 bases), which changes the amino acids
Frameshift mutation
in DNA:
Mutated mRNA:
Wrong amino acids:
ATG
TAC
UAC
ACC
TGG
UGG
GTG
CAC
CAC
Tyrosine Tryptophan
A
T
U
Histadine
Point mutations: Bases are ________
 Harmful when:
 Not harmful when:
Correct DNA
Correct mRNA
CTC
Correct amino acid
CUC
Leucine GAG
Point mutation in DNA
CTC
Arginine
GCG
Mutated mRNA
Wrong amino acid
CGC
A should pair with T, but instead C is mismatched
to T
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Chromosome Mutations:







__________ are changes in genes or chromosomes that can be passed on to
offspring
Mutations…
Chromosomal mutations include changes in …
_________ occurs when an individual has only one of a particular type of
chromosome
_______________ (X0) is an example of monosomy
_______________ occurs when and individual has three of a particular type of
chromosome
Examples of trisomy include:
1. _____________________ (XXY)
2. _____________________ or Trisomy 21 where the individual has three 21st
chromosomes











________________ causes both monosomy & trisomy; results when
chromosomes fail to separate during meiosis
Monosomy and trisomy (aneuploidy) occur in plants and animals and may be
______________.
_____________ offspring have more than two sets of chromosomes; occurs
often in plants (3n, 4n ...)
Environmental factors that cause chromosomes to break causing a change in
chromosomal structure:
_____________ occurs when a piece of a chromosome breaks off & reattaches
to the same place but in the reverse order
_____________ occurs when a chromosome segment breaks off & attaches to a
different chromosome
_____________ occur when the end of a chromosome breaks off & is lost
_____________ (results in retardation & a cat-like cry) is due to a deletion of a
portion of chromosome 5
_____________ occur when a section of a chromosome is doubled
_____________ caused by an abnormal number of repeats (CCG) results in
retardation & long, narrow face becomes more pronounced with age
Draw Figure 12-8 in DaBook
Mutagen:
Examples:
Carcinogen:
Examples:
Karyotype:
4
What information is gained from a karyotype?
DNA Technology
Molecular genetics ~
Genetic engineering ~
DNA extraction ~

_______________ cause cells and nuclei to burst
 The DNA is inherently ________, and can be pulled out of the mixture
 This is called ___________________ DNA
Cutting DNA
Restriction enzymes ~
DNA Fingerprinting (RFLP Analysis):
5
DNA fingerprinting 
In RFLP analysis, the DNA of an organism is cut up into
fragments using restriction enzymes producing a

Because no two individuals have identical DNA, no two
individuals will have
Gel electrophoresis
 technique used to separate the
DNA fragments according to
________
 The fragments are placed in wells
on a sheet of ________, and an
_____________ is applied to the
sheet
 The _______________ are
negatively charged
 Negative DNA moves toward the
_____________ end
 The _________________ will
move the fastest because they are able to move through the pores in the gelatin
faster
 _________ will be produced on the gelatin where the fragments accumulate
 ________ fragments will accumulate near one end of the gelatin (furthest from the
wells), and the ___________, slower-moving ones will remain near the other end
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
DNA bands must be _________ to make them visible
Recombinant DNA ~
Transformation
Plasmid
7
Growth hormones
Human growth hormone (HGH)
List three diseases that could be treated by replacing defective genes with normal
genes.
Transgenic organisms
Genetic pollution
Reproductive cloning
Clone ~
May be produced by _____________ (mitosis)
A ______________ from one organism and an _______________
from
another
organism are fused
 The resulting cell
divides like a
_________________
Cloning “Dolly”
How cloning works...
Human Genome Project Examples of genetic
technology in use today.
 DNA testing –
Paternity, identity
 Genetically engineered
foods – transplanting
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



genes in rice to contain Vitamin A, slow ripening fruits, virus resistant crops, low
fat avocadoes, safer meat
Modified bacteria to make pharmaceutical drugs
Cloning
Stem Cell Research
Selective Breeding – race horses, bulls, champion dogs, hunting dogs, livestock
(cows, sheep, pigs, chickens)
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