Mutation
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Lilli Howard
BIOL/GEN 313
Dr. Vollbrecht
04/08/14
Types of Mutations
Germline Mutations/Somatic Mutations
Base Substitutions
Transition and Transversion
Single Base Substitutions
Insertions/ Deletions
Intra/Intergenic Suppressors
Effects of Mutations
Neutral
Loss of Function/Gain of Function
Causes of Mutations
Tautomeric Shifts
Depurination
Deamination
Chemical Mutagenesis
UV Light
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu
1. Which of the following types of gene mutation in a protein-coding gene usually have the
least severe effects?
a. Missense mutations
b. Nonsense mutations
c. Single base deletions
d. Expansion of a dinucleotide repeat
e. ‘all of the above generate equally severe phenotypes
2. Which of the following is not a reason that understanding mutations is important?
a. Mutations provide stability to genomes
b. Mutations cause inherited diseases
c. Mutations provide variability that is the basis of evolutionary selection
d. Mutations provide information about biological mechanisms
e. Mutations can cause cancer in somatic tissue
3. Which type of mutation is likely to lead to an intragenic suppressor of a forward mutation
that was caused by insertion of a single base pair?
a. Insertion of one additional base pair
b. Insertion of two additional base pairs
c. Deletion of two additional base pairs
d. Transition mutation elsewhere in the gene
e. Transversion mutation elsewhere in the gene
4. Which kind of mutation is most likely to cause loss-of-function of the protein product of
the gene?
a) Transition
b) Transversion
c) Frame shift
d) Missense
e) Spontaneous
5. Which of the following is a defining characteristic of a germ line mutation?
a) A stop codon is abnormally placed within the coding region of gene
b) Abnormal extra nucleotides are found within the coding region of gene
c) The mutation causes cancer in a clonal population of cells within an organism
d) The mutation is found in the progeny of the individual in which it arose
e) The mutation arose in an individual early in its lifespan
6. What is the basis for induction of mutations by ultraviolet light?
a) UV light causes formation of dimers between two adjacent T bases stacked in the double helix
b) UV light causes spontaneous depurination
c) UV light causes spontaneous deamination of cytosine bases
d) UV light causes DNA polymerase to become error prone
e) UV light cleaves the sugar-phosphate backbone of DNA
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu