Unit 4- 2b DNA Mutations Review Lesson

Mutations in DNA

C

What is a mutation?

•Mutation- change in the nucleotide sequence of DNA

Multiple Choice

Any change in the sequence of DNA is...

• transgenic shift
• Single Genotype
• Monohybrid Trait
• Mutation

Why do mutations matter?

➔ Changing nitrogen bases can change the protein that is

being built.
◆ Remember the DNA code is instructions for creating

proteins and running the organism.

➔ 3 nitrogen bases code for an amino acid, amino acids are

monomers of proteins.

➔ Ex. CTA
(Cytosine-Thymine-Adenine)

Types of Mutations

1. Point mutation: AKA Substitution Mutation

•A chemical change in just one base pair

• Example: Substituting a Cytosine (C) for an Adenine (A).

• Can cause the wrong amino acids to be made
• Can cause the early termination of a protein chain if it is a stop

codon (UAA, UGA, UAG)

Multiple Choice

What mutation has occurred here? 
T-G-A-C-C-A
T-G-A-G-C-A

• Substitution
• Deletion
• Insertion
• Frameshift 

Multiple Choice

DNA molecule segment is : TTACGCAAG
The mutated DNA segment is TTACGCAAC. This is an example of ___ mutation.

• Substitution
• Insertion
• Inversion
• Translocation

Multiple Choice

Identify the SUBSTITUTION mutation from the following DNA sequence: 
ATG CCA AAT

• ATG TCA AAT
• ATG CCT AAA T
• ATC CA  AT
• ATG CCA AAT

Multiple Choice

What is the definition of DNA mutation? 

• The original DNA strand
• The strand with four pairs 
• A change in the DNA strand
• The strand in a double helix 

Types of Mutations

2. Frameshift mutation:

•Mutations that change the “frame” of the amino acids
•Involves a gain or loss of a nucleotide which can cause
a change in the codon!
•WORST KIND!
•Examples: insertion and deletions

Frameshift Mutations

•Deletion: nucleotide gets
lost during replication or
transcription

•Insertion: extra
nucleotide is attached
to the sequence

Multiple Choice

If you are missing or have an extra base  at the end of your mutated DNA . What type of mutation occurred?

• Substitution
• Frameshift
• Duplication 
• Insertion

Multiple Choice

Which of the following would result in a frameshift mutation?

• Insertions only
• Substitution only
• Deletion only
• Insertions and Deletions

Multiple Choice

DNA molecule segment is : TTACGCAAG
The mutated DNA segment is TTCGCAAG. This is an example of ___ mutation.

• Substitution
• Deletion
• Insertion
• Inversion

Multiple Choice

Normal-
GAG-CTC-GAC-AGA
Mutant
GAG CTC-CAC-AGA

• no mutation
• substitution
• insertion
• deletion

Multiple Choice

Original: ATC CAT
Mutation: ATC GCAT
What mutation occurred?

• deletion
• insertion
• silent
• transverse

Multiple Choice

A frameshift mutation can occur with either _________ or __________ mutations.

• Addition, division
• Deletion, substitution
• Addition, substitution
• Addition, deletion

Multiple Choice

Which type of mutation is MOST LIKELY to cause the greatest disruption?

• Frameshift

• Silent

• Point

Multiple Choice

Identify the DELETION mutation from the following DNA sequence: 
ATG CCA AAT

• ATG TCA AAT
• ATG CCT AAA T
• ATC CA  AT
• ATG CCA AAT

Multiple Choice

Original: ATC CAT
Mutation: ATC GCAT
What mutation occurred?

• deletion
• insertion
• silent
• transverse