Download DNA mutations 11.3 notes

11.3 Mutations
Review
DNA controls structure and function of cells
because it holds the code to build all proteins.
The Central Dogma is:
. DNA
Amino acid
sequence
mRNA
transcription
translation
1. A change in the DNA sequence is called
a Mutation
A mutation can also be called a mistake in
the DNA
2.
2. Mutations can be cause by errors in,
replication, transcription, or cell
division as well as by forces outside
the cell.
Mutations can occur in
reproductive cells
(sperm or egg)
or
in body cells.
Mutation in sperm or egg
Only offspring affected
New protein
that is better
than before
New protein
hurts
organism or
doesn’t work
at all.
Mutation in body cell
Only adult cells affected
Cell may no
longer work
properly
Cell doesn’t
reproduce
properlymay
lead to cancer
3.
A change in the nucleotide
sequence (a mutation) in an egg cell
or sperm cell [would, would not]
be passed along to the offspring
(child).
4.
When is a mutation helpful?
.
It may produce a new trait that
helps the organisms
5.
5. What are some sources of radiation
that can cause mutations in body
cells?
X-rays, sun, radioactive
materials
6.
A change in a body cell (like a skin
cell) [would, would not ] be passed
along to the offspring.
7.
How can a mutation in a body cell
cause cancer?
The cell may grow and divide too
quickly.
8.
If the DNA is mutated, what will
happen to the mRNA?
It will take the changed info into the
cytoplasm and the tRNA will bring the
wrong amino acid to the rRNA. The
protein will be based on the mutated
information.
Certain types of mutations are
found in the genes or DNA
. Point mutation is the change in a
single base pair.
–EX. When you change one letter in
a sentence:
THE DOG BIT THE CAT.
THE DOG BIT THE CAR.
9.
The change in a single base pair is called
a ________ mutation.
point
.Frameshift mutation is when one base is
deleted or inserted and the whole
sequence shifts.
– EX: If you delete the letter G, from the original
sentence:
THE DOG BIT THE CAT.
THE DOB ITT HEC AT.
– EX: If you insert the letter A, into the
sequence.
THE DOG ABI TTH ECA T.
10
The addition or deletion of a single
base is known as a _____ mutation.
frameshift
Chromosomes carry large amounts of
genetic material and can also have
mutations
Results of chromosomal mutations
Sometimes parts of the chromosomes
break off during mitosis or meiosis. The
pieces may join to the wrong
chromosomes, join backwards or in the
wrong places, or even get lost.
Most common in plants
Few chromosomal mutations are passed
on because the egg usually dies.
12 (no 11)
Chromosomal mutations more
common in [ plants, animals ].
Why are few chromosomal mutations
passed on?
The fertilized egg usually dies.
13.
What is a mutagen?
A mutagen is an outside agent that
causes a mutation.
What are examples of mutagens?
Radiation like: nuclear, X-rays, or U-V rays
from the sun
chemicals like: asbestos and formaldehyde
DNA repair
Organisms have evolved several enzymes
that check and repair DNA, but the more
exposure to a substance, the more
chances for mistakes.
ATT
CAG
DNA complement:
TAA
mRNA strand:
U AA
Point mutation:
TTA
GTC
GUC
GTC