Download MUTATIONS

MUTATIONS
Changes in DNA that affect genetic
information
What Causes Mutations?
 Mutations can be inherited.
 Parent to child
 Mutations can be acquired.
 Environmental damage
 Mistakes when DNA is copied
Significance of Mutations
• Some are harmful
• Down Syndrome
• Some are
beneficial
• Immunity to HIV
• MOST ARE
NEUTRAL!
• Eye color
• Birth marks
Gene Mutations
changes in one or more nucleotides on
one section of DNA
Example: Point, and Frameshift
 Point Mutations – changes in one
or a few nucleotides
THE FAT CAT ATE THE RAT
 1 Nucleotide Substitution
 THE FAT HAT ATE THE RAT
 3 nucleotide Insertion
 THE FAT CAT SAT ATE THE RAT
 3 nucleotide Deletion
 THE FAT ATE THE RAT
Gene Mutations
 Frameshift Mutations – shifts the
reading frame of the genetic
message so that the protein may
not be able to perform its function.
THE FAT CAT ATE THE RAT
 1 nucleotide Insertion
 THE FAT HCA TAT ETH ERA T
 1 nucleotide Deletion
 TEF ATC ATA TET HER AT
Chromosome Mutations
Changes in number and structure of
entire chromosomes
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Original Chromosome
Deletion
Duplication
Inversion
Translocation
ABC * DEF
AC * DEF
ABBC * DEF
AED * CBF
ABC * JKL
GHI * DEF
Karyotype
 Set of
chromosome
photographs
grouped in
order and in
pairs
 Can be used
to diagnose
chromosomal
mutations
Chromosome Mutations
 Down’s Syndrome
 Chromosome 21 does
not separate correctly.
 They have 47
chromosomes in stead
of 46.
 Children with Down’s
Syndrome develop
slower, may have heart
and stomach illnesses
and vary greatly in their
degree of inteligence.
Chromosome Mutations
 Cri-du-chat
 Deletion of material on 5th
chromosome
 Characterized by the cat-like
cry made by cri-du-chat
babies
 Varied levels of mental
handicaps
Pataos Syndrome
Trisomy 13
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Incomplete brain
Severe mental retardation
Cleft lip and palate
Absence of eyes
Heart valve disorder
Average live expectancy = 130 days
Edward’s Syndrome
Trisomy 18
 Clenched fists
 Rocker bottom feet
 Malformed heart
 3 months – 15 years
Sex Chromosome
Abnormalities
 Klinefelter’s
Syndrome
(Hermaphrodite)
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XXY, XXYY, XXXY
Male
Sterility
Small testicles
Breast enlargement
Sex Chromosome
Abnormalities
 Jacob’s Syndrome
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XYY
Normal male traits
Often tall and thin
Associated with antisocial and behavioral
problems
Sex Chromosome
Mutations
 Turner’s Syndrome
 X
 Female
 sex organs don't
mature at
adolescence
 sterility
 short stature
Sex
Chromosome
Mutations
Trisomy X
 Female
 Little or no visible
differences
 tall stature
 learning disabilities
 limited fertility
http://www.angelfire.com/ca2/BornHermaphrodite/
Some mutations even
make it on SNL!