Question 1

Which type of mutation is most likely to result in a protein that is completely nonfunctional due to a premature stop codon?

Accepted Answer

Nonsense mutation

Question 2

A patient presents with sickle cell anemia. Which specific mutation is responsible for this disease?

Accepted Answer

A substitution of thymine for adenine at codon 6 of the beta-globin gene

Question 3

Which equation best describes the Hardy-Weinberg equilibrium for a gene with two alleles, A and a?

Accepted Answer

$$p^2 + 2pq$$ + $$q^2 = 1$

Question 4

Why is the sickle-cell allele more frequent in regions where malaria is common?

Accepted Answer

Heterozygotes for the sickle-cell allele have increased resistance to malaria

Question 5

A frameshift mutation occurs when:

Accepted Answer

One or more base pairs are inserted or deleted, altering the reading frame

Question 6

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that results in the substitution of one amino acid for another

Question 7

A person exposed to mutagens such as radiation or certain chemicals is at increased risk for which of the following?

Accepted Answer

Both chromosomal and point mutations

Question 8

Which of the following is a possible outcome of a base-pair substitution mutation?

Accepted Answer

Silent mutation

Question 9

If a mutation causes a gain of function in a gene, which of the following is true?

Accepted Answer

The gene product has a new or enhanced activity

Question 10

Which of the following best explains why different mutations at the same location in a gene can have different effects?

Accepted Answer

The type of mutation and its effect on the protein determine the outcome

Question 11

A nonsense mutation is most likely to:

Accepted Answer

Shorten the protein by introducing a premature stop codon

Question 12

Which of the following is NOT a cause of mutation?

Accepted Answer

Normal cell division

Question 13

A chromosomal mutation that results in a segment of a chromosome being deleted is called:

Accepted Answer

Deletion

Question 14

Which of the following best describes the effect of a frameshift mutation on the protein product?

Accepted Answer

It may cause extensive missense or immediate nonsense mutations

Question 15

In the context of sickle cell anemia, which genotype provides resistance to malaria?

Accepted Answer

Hb A/Hb S

Question 16

Which of the following best explains why some mutations are neutral?

Accepted Answer

They do not change the amino acid sequence or protein function

Question 17

A person inherits a mutation that causes partial loss of function in a gene. Which of the following is a possible outcome?

Accepted Answer

The person may have a mild disease or altered phenotype

Question 18

Which of the following is an example of a real-world mutagen?

Accepted Answer

Ultraviolet radiation

Question 19

A mutation changes the codon UGA to UGG in mRNA. What is the most likely effect?

Accepted Answer

A missense mutation

Genetic Mutations: Types, Effects, and the Case of Sickle Cell Disease

Study Guide - Practice Questions