Transcript Mutations - Allen ISD

Mutations
and
Genetic Modifications
TEKS BIO 6C
Instructions---READ
EVERYTHING

Today, you will learn about
MUTATIONS. Follow the
powerpoint, watching any videos
that may be presented, and fill in
your notes as you go. Be sure
to read each slide to ensure you
are completing your notes
correctly.
Engage: One Wrong LetterYou have seen this video before. You may choose to watch
it again, or move on to the next slide.
Explore:
What about Mistakes??
Mutation

Any changes to the genetic
material (DNA) of a cell
Mutations
How Mutations Happen

click the link above to watch the
video before moving on

How can mutations occur?
Simple replication errors in DNA
 Environmental Mutagens

Types of Mutations

Point Mutations

Base Pair Substitutions



Base Pair Insertions and deletions




Silent
Missense – new protein (Amino Acid Substitutions)
Triplet Repeats
Frameshift Mutations
Variation in Chromosome Number
Chromosome Abnormalities




Deletions
Translocations
Duplications
Inversions
Point Mutations- one base
change in the DNA sequence
Potential Results of Point Mutation
 Observe what happens when
the following Point Mutations
Occur for each set:
 CCA=Lys
 CCC=Lys
 GGA=Arg
 GGU=Arg
 UCU=Stop
 UCA=Stop


Amino acid meaning is not
altered for each set
This demonstrates a
Silent mutation
Potential Result of Point Mutation


If the amino acid meaning is
changed, cells could be altered
Example: Sickle Cell Anemia

Valine is replaced with Glutamic Acid
Point Mutations:
Frame Shift


Insertion or deletion of one or more bases into the
sequence of the gene
How many DNA nucleotides can a ribosome read at
one time?



three letters (called CODONS) code into 1 amino acid (“word”)
adding or removing one letter changes each subsequent “word”
These mutations can make the DNA meaningless

shortened and functionless protein
ACTIVITY

READ ALL DIRECTIONS ON THE
NEXT SLIDE AFTER PICKING UP
THE PAGE FROM THE FRONT

READ ALL DIRECTIONS ON THE
NEXT SLIDE BEFORE
COMPLETING ACTIVITY

READ ALL DIRECTIONS ON THE
NEXT SLIDE BEFORE
COMPLETING ACTIVITY
ACTIVITY:
“Modeling Chromosomal Mutations”
READ EVERYTHING before moving on

First, read the directions on the “Modeling
Chromosomal mutations” page and follow the
directions about how to complete the “original
chromosome.” Cut out the original chromosome
and paste it to the top of your notes.

Continue with the slideshow AFTER completing
the directions on each slide

Cut out the colored diagram AND question and
glue BOTH near the corresponding slide. (either
on the slide or below it)
Deletion
Frame Shifts

A deletion of
one or more
bases on a
section of the
chromosome.

Color the “deletion” section
on your “modeling
chromosomal mutations”
page, answer the question
that follows, then cut and
glue both onto your slide.
Base Pair Insertions
(Triplet Repeats)


Occurs when
DNA is not
copied correctly
and a segment
is repeated
Ex) Huntington
Disease—CAG
Repeat
Variation in Chromosome Number


Having any
number of
chromosomes
that does not
equal 23 pairs.
Ex) Down
Syndrome –
3 Chromosome
21’s
Chromosome Abnormalities
-Translocations
-Duplications
-Inversions
Translocations

When one piece of
a chromosome
breaks off and
attaches to
another
chromosome

Color the “translocation” section
on your “modeling chromosomal
mutations” page, answer the
question that follows, then cut
and glue both onto your slide.
Duplications

Occurs during
crossing over and one
chromosome ends up
with more genes than
it received.

Color the “duplication” section on your
“modeling chromosomal mutations”
page, answer the question that follows,
then cut and glue both onto your slide.
Inversions

A reversal in the order
of a segment of a
chromosome

Color the “inversion” section on your
“modeling chromosomal mutations”
page, answer the question that follows,
then cut and glue both onto your slide.
Elaboration 1

The next several slides will give
you information concerning a
particular mutation.

Use the small blue papers to
write your responses. LABEL
EACH SECTION CLEARLY!

You will be graded on your
responses.
Types of Mutations--1

DNA Sentence -

Mutation -
a)
b)
c)
THE FAT CAT ATE THE WEE RAT
THE FAT HAT ATE THE WEE RAT
If this was a DNA sequence, what would this type of
mutation be called?
Could this change cause the protein sequence to
change? How?
If this type of mutation occurred, what, if any, might be
the possible consequence for the organism?
Types of Mutations--2

Original Sample Gene

Mutation -
a)
b)
c)
- THE FAT CAT ATE THE WEE RAT
THE FAT KAT ATE THE WEE RAT
If this was a DNA sequence, what would this type of
point mutation be called?
Was the meaning of the gene sentence altered?
If this type of mutation occurred, would there be any
consequence for the organism? Yes/No. Why or why
not?
Types of Mutations--3

Original Sample Gene

Mutation -
a)
b)
- THE FAT CAT ATE THE WEE RAT
THE FAT CAA TET HEW EER AT
If this was a DNA sequence, what would this type of
mutation (chromosome abnormality) be called?
Could this change cause the polypeptide sequence to
change? Yes/No
How?
Types of Mutations--4

Original Sample Gene

Mutation -
a)
b)
- THE FAT CAT ATE THE WEE RAT
THE FAT ATE THE WEE RAT
If this was a DNA sequence, what would this type of
mutation be called?
Could this change cause the polypeptide sequence to
change? How?
Types of Mutations--5
- THE FAT CAT ATE THE WEE RAT
THE FAT CAT XLW ATE THE WEE RAT

Original Sample Gene

Mutation -
a)
b)
If this was a DNA sequence, what would this type of
mutation be called?
Could this change cause the polypeptide sequence to
change? How?
Evaluation


The next several slides will
show different types of
mutations you’ve learned.
On the back of your sheet, write
the type of mutation you think is
represented in the picture.
What Type of Mutation?--6
What Type of Mutation?--7
What Type of Mutation?--8
What Type of Mutation?--9
What Type of Mutation?--10
Genetic Modification--Where
can it lead?