$$\text{New reading frame} = \text{Original reading frame} \pm 1$$

Question 1

Which type of DNA mutation is most likely to result in a frameshift mutation?

Accepted Answer

Base insertion

Question 2

A missense mutation results in which of the following changes at the protein level?

Accepted Answer

Replacement of one amino acid with another

Question 3

Which equation best represents the effect of a frameshift mutation on the reading frame of a gene?

Accepted Answer

$$	ext{New reading frame} = 	ext{Original reading frame} \pm 1$$

Question 4

Which of the following best describes a silent mutation?

Accepted Answer

A mutation that does not change the amino acid sequence

Question 5

A patient’s DNA sequence has a single base substitution that changes a codon from UAU (tyrosine) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 6

Which of the following is a transition mutation?

Accepted Answer

A purine is replaced by another purine

Question 7

Why are most DNA mutations considered neutral?

Accepted Answer

They often occur in regions that do not affect gene function

Question 8

Which of the following mutations is least likely to affect the function of a protein?

Accepted Answer

Silent mutation

Question 9

A base substitution in the third position of a codon often results in which type of mutation?

Accepted Answer

Silent mutation

Question 10

If a mutation changes the primary structure of a protein, what is the most likely consequence?

Accepted Answer

The protein’s folding and function may be altered

Question 11

Which of the following best explains why some amino acid substitutions do not affect protein function?

Accepted Answer

Some substitutions occur in regions not critical for protein function

Question 12

A mutation that changes a codon from GAA (glutamic acid) to GAG (glutamic acid) is classified as:

Accepted Answer

Silent mutation

Question 13

Which of the following is true regarding nonsense mutations?

Accepted Answer

They introduce a premature stop codon

Question 14

A DNA mutation that deletes two bases from a coding region will most likely result in:

Accepted Answer

A frameshift mutation

Question 15

Which of the following equations represents the number of possible codons given four bases and three positions?

Accepted Answer

$$4^3$$

Question 16

A mutation in the active site of an enzyme is most likely to:

Accepted Answer

Render the enzyme defective

Question 17

Which of the following is NOT a potential impact of a point mutation?

Accepted Answer

Frameshift mutation

Question 18

If a DNA sequence undergoes a transversion mutation, which of the following occurs?

Accepted Answer

A purine is replaced by a pyrimidine or vice versa

Question 19

Which of the following best describes the relationship between DNA sequence and protein structure?

Accepted Answer

Changes in DNA sequence can alter the folding and function of a protein

Question 20

A mutation that does not change the protein’s function is most likely:

Accepted Answer

A silent mutation or a missense mutation in a non-critical region

Classification and Impact of Mutations in Genetics

Study Guide - Practice Questions