Transcript MUTATIONS

Warm-Up #17
2/22/13
Identify the type of mutation:
1.Gene or Chromosome
2. Point, Frame Shift, Deletion, Duplication,
Inversion, or Translocation
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QRSSST UVWX
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Mutation Quiz Study Guide
1) What is a mutation?
2) What are the 2 causes of
3)
4)
5)
6)
7)
8)
9)
mutations?
What are the 3 affects of mutation?
What is a mutagen? List 5
examples.
What two places can a mutation
occur (in the body)?
What are the 2 types of mutations?
How are they different?
What is nondisjunction? What are
the 3 types.
Be able to identify these types of
mutations. (ON NEXT SLIDE)
Be able to find the mutation in the
chart. (ON NEXT SLIDE)
8
THESE WERE ON
YESTERDAY’S
HOMEWORK
9
Warm-Up #16
2/21/13
1) What did the scientist Franklin discover?
2) Watson and crick are responsible for
what?
3) What type of RNA is pictured?
4) What is polymerase and what does it do?
5) Using the following words list the steps to
transcription and translation.
Nucleus, mRNA, tRNA, Ribosome, DNA,
Amino Acids
MUTATIONS
Unit 7: Molecular Genetics
Chapters 12 & 13
Today is About…
 Essential Question:
 How can a mutation
in DNA affect an
organisms ability to
survive?
 ESSENTIAL
QUESTION
is on back of
the notes!
 Objectives:
1. Contrast gene mutations
2.
3.
4.
5.
and chromosomal
mutations
Describe a typical gene
Describe how the lac
genes are turned on and
off
Explain how must
eukaryotic genes are
controlled
Relate gene regulation
to development
Mutations can be visible
Polydactyly
Conjoined twins
Or microscopic!
Sickle cell anemia
Mutations can be fatal
Spina bifida
Or cause medical disorders.
Hemophilia
Mutation
 A change in the genetic material.
Mutations
 May be harmful, beneficial, or
cause no effect.
 Harmful Mutation: Sickle Cell
 Beneficial Mutation: Antibiotic Resistant
Bacteria (beneficial to the bacteria)
 No Effect Mutation: Same Protein Made
 May occur in somatic cells—not
inheritable.
 May occur in gametes—inheritable.
Mutations are caused by mutagens.
 Radiation
 Hormones
 Viruses
 Temperature
 Chemicals
Two types of mutations:
 Gene mutations
 Chromosomal mutations
Gene mutations involve
individual genes (proteins). Two
types are:
 Point mutations--change of one
nucleotide. (substitution)
 Frame shift mutations--loss or
gain of one nucleotide.
 Examples include sickle cell
anemia, cystic fibrosis, and
Duchenne muscular dystrophy.
Point
Mutation
Frameshift
Mutations
Deletion
Substitution
Insertion
Chromosomal mutations
involve segments or whole
chromosomes.
 Nondisjuntion
 Deletion
 Duplication
 Inversions
 Translocations
Nondisjunction (ON BACK)
 One cell has an extra chromosome while
the other lacks one.
 During meiosis chromosomes stick
together instead of pulling apart
 Produces an odd number of chromosomes
 Ex. get 45 or 47- Instead of 46 normal –
Types of Nondisjuction
(ON BACK)
 Trisomy – 1 extra chromosomes
 Down’s Syndrome, three of chromsome 21
 Klinefleter’s Syndrome – Extra X = XXY
 Jacob’s syndrome- Extra Y= XYY
 Monosomy – missing chromosome
 Ex. Turner’s Syndrome – Female with 1 X = OX
 Polyploid – 4 or more chromosomes
 Instead of 1n, gametes are 3n or 4n
 Common in plants
 Lethal in humans
Del ions
 Part of or an entire chromosome
is missing.
Deletion
The entire B gene has been
deleted from the
chromosome.
EX: Cri du Chat is a deletion
mutation. An affect person
sounds like a cat when they cry.
 Part of
chromosome 5 is
missing in this rare
genetic disorder.
 Duplipliplication
 Part of a
chromosome
is duplicated.
Duplication
The entire B gene has
been duplicated so there
are two copies of it on
one chromosome.
Fragile X
Syndrome
One of the most
common causes
of mental
retardation is
Fragile X
syndrome
where there are
55-200 copies
of a gene on the
X chromosome.
er
Inv
sions
 Part of a
chromosome is
cut out and
reattached in
the wrong
direction.
Inversion
The B and C genes have
flipped around with the D
and E genes.
Chromosome inversion
Normal
chromosome
Chromosome with
inversion--often has
normal individual.
 Trans
tions
 Part of a
chromosome is
cut out and
reattached on
a differentloca
chromosome.
Translocation
The DEF and JKL genes
have broken off and moved
to another chromosome.
Philadelphia translocation
 This is found
in tumor cells
of patients
with chronic
myelogenous
leukemia.
CML (Leukemia) vs. healthy blood
Gene regulation
 A cell only uses some genes;
other genes are kept “silent”
(turned off).
 Sites near the promoter
determine if a gene is turned
on or off.
Gene regulation
 Prokaryotes have operons-
genes that work together and
can be turned on and off.
Gene regulation
 Eukaryotes control genes
individually
 A liver cell has all of the genetic
code- uses only parts of the code
needed for liver functions.
PLEASE play mutation
video located on the
desk top now