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Welcome to Genetic Mutations!

https://www.youtube.com/watch?v=6zMIl
7x2WSY
Share out!
Today’s objective:
 SWBAT explain how genetic
mutations occur
 SWBAT distinguish between the 3
types of genetic mutations


GENETIC DISORDERS ARE CAUSED
BY GENETIC MUTATIONS!!!!!!
A. Introduction to Mutations
-A mutation is a change in DNA sequence
(order of nucleotides).
-Mutations are important because they
increase genetic variation.
Mutations in Body Cells
-Mutations in body
cells cannot be
passed on to your
children, however,
they can cause
cancer or other
problems in your
body.
A cancer cell.
Cancer as a result of mutations in
body cells:
A person with skin cancer-This is why it’s
important to always wear sunscreen!
Cancer as a result of mutations in
body cells:
Tongue cancer and lung cancer
are often caused by changes in
body cells as a result of smoking,
so don’t smoke!!!
Mutations in Reproductive (Sex)
Cells
-Mutations in sex cells (sperm and egg
cells) can lead to changes in the DNA
sequence which can be passed down to
a person’s children.
Mutations in sex cells
-X-men and X-women
would be a result of
mutations in sex
cells. These
people inherited
mutated (changed)
DNA from their
parents:
Good vs. Bad Mutations
Mutations can be good as well as bad. A good
mutation could lead to a change in a protein
that allows an animal to run faster or see
better. A bad mutation could lead to a
change in a protein that causes a genetic
disease such as Sickle Cell Anemia or
Hemophilia.
TURN AND TALK

WHAT IS A MUTATION?

WHAT IS THE MAIN DIFFERENCE
BETWEEN MUTATIONS IN SEX CELLS
AND MUTATIONS IN BODY CELLS?
B. Gene Mutations
There are 3 main types of
gene mutations:
 1. POINT MUTATIONS


SUBSTITUTIONS
2. SILENT MUTATIONS
 3. FRAMESHIFT
MUTATIONS

INSERTIONS
 DELETIONS

1. Point mutation
-Point mutation-a change in one base pair in a DNA
sequence.
Example: AUG=Met
AAG=Lys
-A point mutation can cause an amino acid to change,
which will change the structure of the protein being
made.
POINT MUTATION
Picture of A Point Mutation
mRNA
Normal
Protein
Stop
Replace G with A
mRNA
Point
mutation Protein
Stop
Point mutations in our lives!
-Sickle cell anemia is a blood disease caused
by a point mutation.
-A single nucleotide is changed from “A” to “T” which
causes the amino acid to change from glutamic
acid to valine:
Normal: ACT CCT GAG GAG
Amino Acids: Thr – Pro – Glu – Glu
Sickle cell: ACT CCT GTG GAG
Amino acids:Thr – Pro – Val – Glu
Point mutations in our lives!
-People with sickle cell
anemia often
experience a lot of
pain and swelling
and have trouble
exercising.
Sickle cells also can’t carry
Oxygen as effectively as normal
Cells.
2. SILENT MUTATION

A TYPE OF
MUTATION THAT
RESULTS IN A
CHANGE IN
CODON BUT
DOES NOT
CHANGE THE
AMINO ACID
CREATED.
Codons can code for the same Amino
acid!
Silent Mutations

Single nucleotide mutation that does not
result in a change in the amino acid
sequence of the protein made
THINK PAIR SHARE
WHAT IS THE DIFFERENCE BETWEEN
A POINT MUTATION AND A SILENT
MUTATION?
3. Frameshift mutation
-Frameshift mutation- Adding or deleting
nucleotides to a DNA sequence.
-A frameshift mutation is much worse than a
point mutation because it causes the entire
DNA sequence to be shifted over!
Example: DNA: ATTAAACCG
Delete this T
ATAAACCG
2 types of Frameshift mutations:
INSERTION
DELETION
FRAME-SHIFT MUTATIONS:
Insertion: Nucleotide added –
Entire DNA sequence changed
 Deletion: Nucleotide missing –
Entire DNA sequence changed

V. Frameshift mutation
Deletion of U
Frameshift
mutation
mRNA
Protein
Frameshift Mutations
Crohn’s Disease is caused by a
frameshift mutation.
 It causes inflammation to the digestive
tract.

THINK PAIR SHARE

WHAT IS THE DIFFERENCE
BETWEEN A POINT MUTATION AND A
FRAMESHIFT MUTATION?
Difference between a point mutation
and a frameshift mutation.
BRAIN POP VIDEO
https://www.youtube.com/watch?v=efstlgo
ynlk
GUIDED PRACTICEWHITEBOARDS
Is this a point mutation or a frameshift mutation?
-It’s a point mutation because only one nucleotide
changed!
Questions:
THE DOG BIT THE CAT
THE DOG BIT THE CAR
Point or frameshift?
Point!
Questions
THE DOG BIT THE CAT
THE DOB ITT HEC AT
Point or frameshift?
-frameshift
GUIDED PRACTICE
WHAT IS THE NAME OF THE TYPE OF
MUTATION THAT RESULTS IN A
CHANGE IN CODON BUT DOES NOT
CHANGE THE AMINO ACID?
SILENT MUTATION

A TYPE OF
MUTATION THAT
RESULTS IN A
CHANGE IN
CODON BUT
DOES NOT
CHANGE THE
AMINO ACID
CREATED.
GUIDED PRACTICE

What type of frame-shift mutation is
shown below?
Answer
INSERTIONFrameshift
GUIDED PRACTICE

What type of frame-shift mutation is
shown below?
Answer
DELETIONFrameshift

WHAT TYPE OF MUTATION IS
SHOWN BELOW?
Answer
POINT

BEFORE THE MUTATION, A DNA
CODON CODES FOR THE AMINO
ACID VALINE. AFTER THE MUTATION,
THE DNA CODON STILL CODES FOR
VALINE.

WHAT TYPE OF MUTATION IS THIS?
Answer
SILENT
Objective

Today’s objective:

SWBAT explain how genetic mutations
occur
 SWBAT distinguish between the 3 types of
genetic mutations
Rate 1-5 on how confident you feel with these objectives
1- Poor
5- Excellent