BIO 325 Exam 3 Study Questions and
Answers Graded A+ 2026
Mutation of a promoter sequence may ______ the rate of transcription -Correct
Answer ✔-increase or decrease
Mutation of a regulatory element/operator site may ___ the ability of the gene to
be properly regulated -Correct Answer ✔-disrupt
Mutatino of the 5'-UTR/3'-UTR may alter the ability of the ___ to be translated
and may alter ___ stability -Correct Answer ✔-mrna; mrna
Mutation of the splice recognition sequence may alter the ability of ____ to be
properly spliced -Correct Answer ✔-pre-mrna
Intragenic supressor -Correct Answer ✔-when the second mutant site is within the
same gene as the first (change in protein structure that compensates for an
abnormality in protein structure caused by the first mutation)
Intergenic suppressor -Correct Answer ✔-suppressor mutation in a different gene
from the first mutation (find info about proteins that have similar or redundant
functional roles)
_______ mutations are changes in DNA structure that result form abnormalities in
biological processes -Correct Answer ✔-spontaneous
_____ mutations are caused by environmental agents -Correct Answer ✔-induced
Name the cause of this spontaneous mutation: Abnormal crossing over may cause
deletions, duplications, translocations, and inversions -Correct Answer ✔-Aberrant
recombination
, Name the cause of this spontaneous mutation: Abnormal chromosomal
segregation may cause aneuploidy or polyploidy -Correct Answer ✔-Aberrant
segregation
Name the cause of this spontaneous mutation: Mistake in DNA polymerase
causing a point mutation -Correct Answer ✔-Errors in DNA replication
Name the cause of this spontaneous mutation: elements inserting themselves into
the sequence of a gene -Correct Answer ✔-Transposable elements
Name the cause of this spontaneous mutation: linkage between purines &
deoxyribose spontaneously breaks. If not fixed, can lead to a mutation -Correct
Answer ✔-Depurination
Name the cause of this spontaneous mutation: Cytosine and 5-methylcytosine
spontaneously deaminates to create uracil or thymine -Correct Answer ✔-
Deamination
Name the cause of this spontaneous mutation: Spontaneous shifts in base
structure causing mutations if they occur immediately prior to DNA replication -
Correct Answer ✔-Tautomeric shifts
Name the cause of this spontaneous mutation: The products of normal metabolic
processes, such as reactive oxygen species (ROS) may be chemically reactive
agents taht can alter teh structure of DNA -Correct Answer ✔-Toxic metabolic
products
Name the cause of this induced mutation: substances that may cause changes in
the structure of DNA -Correct Answer ✔-chemical agents
Name the cause of this induced mutation: physical phenomena that can damage
the DNA -Correct Answer ✔-UV light & X-rays
Answers Graded A+ 2026
Mutation of a promoter sequence may ______ the rate of transcription -Correct
Answer ✔-increase or decrease
Mutation of a regulatory element/operator site may ___ the ability of the gene to
be properly regulated -Correct Answer ✔-disrupt
Mutatino of the 5'-UTR/3'-UTR may alter the ability of the ___ to be translated
and may alter ___ stability -Correct Answer ✔-mrna; mrna
Mutation of the splice recognition sequence may alter the ability of ____ to be
properly spliced -Correct Answer ✔-pre-mrna
Intragenic supressor -Correct Answer ✔-when the second mutant site is within the
same gene as the first (change in protein structure that compensates for an
abnormality in protein structure caused by the first mutation)
Intergenic suppressor -Correct Answer ✔-suppressor mutation in a different gene
from the first mutation (find info about proteins that have similar or redundant
functional roles)
_______ mutations are changes in DNA structure that result form abnormalities in
biological processes -Correct Answer ✔-spontaneous
_____ mutations are caused by environmental agents -Correct Answer ✔-induced
Name the cause of this spontaneous mutation: Abnormal crossing over may cause
deletions, duplications, translocations, and inversions -Correct Answer ✔-Aberrant
recombination
, Name the cause of this spontaneous mutation: Abnormal chromosomal
segregation may cause aneuploidy or polyploidy -Correct Answer ✔-Aberrant
segregation
Name the cause of this spontaneous mutation: Mistake in DNA polymerase
causing a point mutation -Correct Answer ✔-Errors in DNA replication
Name the cause of this spontaneous mutation: elements inserting themselves into
the sequence of a gene -Correct Answer ✔-Transposable elements
Name the cause of this spontaneous mutation: linkage between purines &
deoxyribose spontaneously breaks. If not fixed, can lead to a mutation -Correct
Answer ✔-Depurination
Name the cause of this spontaneous mutation: Cytosine and 5-methylcytosine
spontaneously deaminates to create uracil or thymine -Correct Answer ✔-
Deamination
Name the cause of this spontaneous mutation: Spontaneous shifts in base
structure causing mutations if they occur immediately prior to DNA replication -
Correct Answer ✔-Tautomeric shifts
Name the cause of this spontaneous mutation: The products of normal metabolic
processes, such as reactive oxygen species (ROS) may be chemically reactive
agents taht can alter teh structure of DNA -Correct Answer ✔-Toxic metabolic
products
Name the cause of this induced mutation: substances that may cause changes in
the structure of DNA -Correct Answer ✔-chemical agents
Name the cause of this induced mutation: physical phenomena that can damage
the DNA -Correct Answer ✔-UV light & X-rays
