2. FOCUS QUESTIONS
Describe what a mutation is and how it can affect an organism?
What are 3 different kinds of mutations?
Explain how a change in the sequence of nitrogen base in a DNA molecule could result in a gene mutation?
Explain how the environment can affect the way some genes are expressed?

3. MUTATIONS
Mutations
1. Genes are actually ________________ of DNA molecules. Any alteration of the DNA sequence is called a _________________. A mutation changes the _____________ message carried by the gene. Many mutations involve the __________________ of one base for another. This will often cause a different _______________to be placed in a particular position in the growing ___________ chain.
Types of Mutations
2. Some mutations involve the ___________ of an additional base into an existing DNA sequence. Insertion mutations affects all of the ________ past the change.
SEGMENTS
MUTATION
NORMAL
SUBSTITUTION
AMINO ACID
PROTEIN
INSERTION
CODE

4. Use the genetic code to find the answer
INSERTION MUTATIONS
Example of Insertion mutation:
ORIGINAL DNA TEMPLATE STRAND CODING FOR PART OF PROTEIN
C A T T A G G A T
MUTATED STRAND CARRYING ALTERED CODE FOR THE PROTEIN
C A T T A G G A T
3. Some mutations involve the ____________ of an additional base into an existing DNA sequence.
4. Another type of mutation involves the ____________ of a base from the normal gene sequence. This would also _________ all the code past the change.
Does this insertion mutation affect the overall protein?
Use the genetic code to find the answer
Step #1: transcribe normal DNA to mRNA
C A T T A G G A T  G U A A U C C U A
Step #2: translate mRNA to amino acids
GUA AUC CUA
Val lle Leu
Step #3: transcribe mutated DNA to mRNA
C A T T T A G G A T  G U A A A U C C U A
Step #4: translate mRNA to amino acids
GUA AAU CCU A
Val Asn Pro X T
insertion
deletion
alter

5. Use the genetic code to find the answer
DELETION MUTATIONS
Example of Deletion mutation:
ORIGINAL DNA TEMPLATE STRAND CODING FOR PART OF PROTEIN
C A T T A G G A T
MUTATED STRAND CARRYING ALTERED CODE FOR THE PROTEIN
C A T A G G A T
5. Some mutations occur when the bases within a gene are ________________ rearranged. This is called an _____________ mutation. This too, alters the genetic code and can alter the shape and possibly the function of the protein causing severe problems.
Does this deletion mutation affect the overall protein?
Use the genetic code to find the answer
Step #1: transcribe normal DNA to mRNA
C A T T A G G A T  G U A A U C C U A
Step #2: translate mRNA to amino acids
GUA AUC CUA
Val lle Leu
Step #3: transcribe mutated DNA to mRNA
C A T A G G A T  G U A U C C U A
Step #4: translate mRNA to amino acids
GUA U C C U A
Val Ser XX
accidently
inversion

6. Use the genetic code to find the answer
INVERSION MUTATIONS
Example of an inversion mutation:
ORIGINAL DNA TEMPLATE STRAND CODING FOR PART OF PROTEIN
C A T T A G G A T
MUTATED STRAND CARRYING ALTERED CODE FOR THE PROTEIN
C A T G A T G A T
6. All of these alterations are _________ and can occur anywhere along the DNA molecule. It is very difficult to predict.
When a DNA sequence is changed, it is quite likely that the protein it codes for may be assembled _____________.
Does this inversion mutation affect the overall protein?
Use the genetic code to find the answer
Step #1: transcribe normal DNA to mRNA
C A T T A G G A T  G U A A U C C U A
Step #2: translate mRNA to amino acid
GUA AUC CUA
Val lle Leu
Step #3: transcribe mutated DNA to mRNA
C A T G A T G A T  G U A C U A C U A
Step #4: translate mRNA to amino acids
GUA C U A C U A
Val Leu Leu
RANDOM
INCORRECTLY