Bell Ringer 3-27-09mparkerbiology.weebly.com/uploads/1/0/8/5/108540927/mutations_… · How many...
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MUTATIONS Mutations Great Pacific Media Clip Ted Ed – Where do genes come from?
Transcript of Bell Ringer 3-27-09mparkerbiology.weebly.com/uploads/1/0/8/5/108540927/mutations_… · How many...
MUTATIONSMutations Great Pacific Media Clip
Ted Ed – Where do
genes come from?
You are a mutant…
How many cells reproduce in our bodies everyday?
2,000,000,000,000
How many A,T,G, &C must be replicated so that a cell can
reproduce?
3,000,000,000
How many mistakes are missed and get passed on to
daughter cells?
3 per cell
How many mutations are made in our body everyday?
6,000,000,000,000
You’re welcome!
Junk DNA
What are the effects of mutations?
Mutations may help, harm,
or have no effect
Depends on where the
mutation occurs.
Depends on how much DNA
is affected
Lead to genetic variation in
the population
What is a Mutation?
Mutation – a change in the DNA or the amount of genetic material in an organism
What causes mutations?
Mistakes during DNA replication.
DNA polymerase and other enzymes catch some mistakes, but
not all
Mutagens – cause DNA to change shape so that the DNA
replicates incorrectly
Examples: radiation, UV light, cigarette smoke
Are mutations heritable?
Mutations are only
inherited if the mutation
occurs in the gamete
(sperm and egg).
If a mutation occurs in one
of your skin cell, it can
affect you, but not your
children.
Original (Not Mutated) DNA Sequence
Silent Mutation (substitution)
Causes no change to the
protein because it codes for
the same amino acid
Missense Mutation (substitution)
Causes a codon to code for
a different amino acid
Nonsense Mutation (substitution)
Causes a codon to change
to a STOP codon
Protein synthesis stops
early and the protein may
not function
Insertion
One or more
nucleotides are added
to the DNA which
changes the entire
protein sequence from
that point on
Deletion
One or more
nucleotides are
removed from the DNA
which changes the
entire protein sequence
from that point on
Nondisjunction
Occurs when homologous
chromosomes fail to separate
during meiosis I
One gamete ends up with an extra
chromosome and one is missing a
chromosome
Down syndrome – extra 21
chromosome
Aka – trisomy 21
Mutations Constructed ResponseUse the DNA sequence from your bell work.
A mutation occurs and the
5th nucleotide changes to
a T.
Transcribe to mRNA.
Translate to amino acids.
What type of mutation
happened?
(silent, missense, nonsense,
insertion, deletion)
How do you know?
TAC AGC CGT GGT CAG ACT
AUG UAG GCA CCA GUC UGA
Met. STOP
DNA
mRNA
AA/
protein
A mutation occurs and the 5th nucleotide is changed to
an T. Show the new DNA, mRNA, and protein.
T
What type of mutation occurred? Nonsense
Mutations Constructed ResponseUse the DNA sequence from your bell work.
A mutation occurs and the
10th nucleotide changes
to a T. Transcribe and
translate the mutated
sequence. What type of
mutation happened?
How do you know?
A mutation occurs and the
5th nucleotide changes to
a T. Transcribe and
translate the mutated
sequence. What type of
mutation happened?
How do you know?
TAC AGC CGT GGT CAG ACT
AUG UCG GCA ACA GUC UGA
Met. Ser. Ala. Thr. Val. STOP
DNA
mRNA
AA/
protein
A mutation occurs and the 10th nucleotide is changed to
an T. Show the new DNA, mRNA, and protein.
T
What type of mutation occurred? Missense
TAC AGC CGT GGT CAG ACT
AUG UAG GCA CCA GUC UGA
Met. STOP
DNA
mRNA
AA/
protein
A mutation occurs and the 5th nucleotide is changed to
an T. Show the new DNA, mRNA, and protein.
T
What type of mutation occurred? Nonsense
