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7 Mutations and Genetic Variation Online Quiz Questions

Use this free practice quiz with 20 questions to review 7 Mutations and Genetic Variation, test your knowledge, and prepare for your next test or exam.

20 questions
01
True or false
1 point

True or false: DNA damage is already a mutation even if it is repaired without changing the DNA sequence.

  1. A

    True

  2. B

    False

02
Written response
1 point

What is the name of the spontaneous chemical reaction in which a DNA base loses an amino group?

03
Choose one
1 point

A DNA change occurs in a cell that will give rise to an egg or sperm. Which statement best describes its inheritance potential?

  1. A

    A mutation in a somatic cell is generally inherited, but a mutation in a germ cell is not.

  2. B

    A mutation in a germ cell may be passed to offspring, but a somatic-cell mutation generally is not.

  3. C

    Mutations in either cell type are always passed to offspring.

  4. D

    Neither cell type can pass a mutation to offspring.

04
Fill in the blank
1 point

As replication occurs, DNA polymerase corrects many copying errors through .

05
True or false
1 point

True or false: The same DNA change can have different consequences in different biological contexts.

  1. A

    True

  2. B

    False

06
Choose one
1 point

A coding sequence gains one nucleotide. What is the most likely consequence of this insertion?

  1. A

    It changes only the amino acid at the position of the insertion and leaves downstream codons unchanged.

  2. B

    It removes or adds one amino acid without changing the reading frame.

  3. C

    It shifts the reading frame, changing downstream codons and often introducing an early stop.

  4. D

    It necessarily has no effect on the encoded protein.

07
Choose one
1 point

A chromosome acquires an extra copy of a segment that contains a gene. Which type of larger-scale mutation best describes this change?

  1. A

    A chromosome segment containing a gene is copied, creating an extra copy.

  2. B

    A single nucleotide is replaced by another nucleotide.

  3. C

    A damaged base is removed and its gap is filled.

  4. D

    A DNA strand is broken and its ends are joined.

08
Written response
1 point

What term describes a substitution in a protein-coding sequence that changes a codon but still specifies the same amino acid?

09
Fill in the blank
1 point

The repair pathway that removes a damaged or chemically altered DNA base and then fills and seals the gap is .

10
Choose all
1 point

Which statements accurately describe mismatch repair? Select all that apply.

  1. A

    It recognizes certain mismatched bases or small insertion–deletion loops.

  2. B

    It removes part of the newly copied strand.

  3. C

    It uses the newly copied strand as the template for replacing the original strand.

  4. D

    It replaces the removed section using the original strand as a template.

11
Choose all
1 point

Which statements correctly describe ways cells can repair double-strand breaks? Select all that apply.

  1. A

    Homologous recombination can use a matching DNA sequence as a template.

  2. B

    Non-homologous end joining joins broken ends directly.

  3. C

    Direct joining can sometimes introduce small sequence changes.

  4. D

    Both pathways repair breaks by removing a short stretch containing a bulky lesion.

12
Choose one
1 point

Ultraviolet radiation and some chemicals can induce DNA changes. What is the general term for agents that can cause mutations?

  1. A

    Proofreading enzymes

  2. B

    Mutagens

  3. C

    Codons

  4. D

    Somatic cells

13
Open ended
1 point

Explain how a mutation in a protein-coding sequence could affect a cell differently from a mutation in a gene's regulatory sequence. Include one possible consequence of each.

14
Choose one
1 point

A single-nucleotide substitution changes a codon, but the altered codon still specifies the same amino acid. How is this substitution classified?

  1. A

    Silent

  2. B

    Missense

  3. C

    Nonsense

  4. D

    Frameshift

15
Written response
1 point

A mutation may be passed to offspring if it occurs in what type of cell?

16
Choose one
1 point

A coding sequence acquires an insertion of three nucleotides. What is the expected reading-frame effect?

  1. A

    It shifts the reading frame and changes every downstream codon.

  2. B

    It adds an amino acid without shifting the reading frame.

  3. C

    It necessarily converts the codon into a stop codon.

  4. D

    It cannot affect the protein sequence.

17
True or false
1 point

During mismatch repair, the cell removes part of the original template strand and uses the newly copied strand as a template.

  1. A

    True

  2. B

    False

18
Choose one
1 point

Which repair pathway removes a short stretch of DNA containing a bulky, helix-distorting lesion?

  1. A

    Base-excision repair

  2. B

    Mismatch repair

  3. C

    Nucleotide-excision repair

  4. D

    Non-homologous end joining

19
Written response
1 point

What is the name of the double-strand break repair pathway that uses a matching DNA sequence as a template?

20
Choose one
1 point

A mutation occurs in a gene's regulatory sequence rather than its protein-coding sequence. Which effect is possible?

  1. A

    It must change the amino acid sequence of the protein.

  2. B

    It can change when or how much RNA is produced.

  3. C

    It always prevents the gene from being copied.

  4. D

    It can only affect the DNA sequence of neighboring genes.