Question 1

A mutation occurs in the somatic tissue of a zebrafish, as shown in the first image. Which of the following statements best describes the consequence of this mutation?

Accepted Answer

The mutation will only affect the cells derived from the mutated somatic cell and will not be inherited by offspring.

Question 2

Refer to the second image. If a germline mutation occurs in a zebrafish, what is the most likely outcome for its offspring?

Accepted Answer

All offspring will inherit the mutation in every cell.

Question 3

The p53 protein, as shown in the third image, is known as the 'guardian of the genome.' Which of the following best describes its role in the cell?

Accepted Answer

It regulates multiple cellular processes including cell cycle arrest, apoptosis, and DNA repair in response to DNA damage.

Question 4

A family pedigree (fourth image) shows a pattern of inheritance for a disease. If the disease is caused by a germline mutation in the Tp53 gene, what is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 5

Which type of chromosomal rearrangement is depicted in the sixth image, where a segment of the chromosome is missing?

Accepted Answer

Deletion

Question 6

In the seventh image, a segment of the chromosome is repeated. What is the most likely consequence of this chromosomal rearrangement?

Accepted Answer

Altered gene dosage and potential problems during meiosis

Question 7

A chromosome segment is reversed end to end, as shown in the tenth image. What is this type of chromosomal rearrangement called?

Accepted Answer

Inversion

Question 8

In the eleventh image, genetic material is exchanged between two nonhomologous chromosomes. What is the name of this chromosomal rearrangement?

Accepted Answer

Translocation

Question 9

A DNA sequence changes from $$	ext{GGG AGT GTA GAT CGT} to$$ $$	ext{GGG AGT GCA GAT CGT} as $$shown in the thirteenth image. What type of mutation has occurred?

Accepted Answer

Base substitution

Question 10

Using the genetic code chart (fourteenth image), what amino acid is encoded by the codon $$	ext{GCA}$$?

Accepted Answer

Alanine

Question 11

A base substitution changes a codon from $$	ext{GTA} to$$ $$	ext{GCA}. $$Using the genetic code chart, what type of mutation is this if the original codon encoded valine and the new codon encodes alanine?

Accepted Answer

Missense mutation

Question 12

Which of the following best describes a transition mutation?

Accepted Answer

A purine is replaced by another purine, or a pyrimidine is replaced by another pyrimidine

Question 13

A DNA sequence undergoes a single nucleotide insertion, as shown in the nineteenth image. What is the most likely consequence of this mutation?

Accepted Answer

Frameshift mutation

Question 14

Which DNA repair mechanism is most likely to repair a pyrimidine dimer caused by UV light?

Accepted Answer

Nucleotide excision repair

Question 15

A patient inherits a mutant allele of BRCA1, a gene involved in homologous recombination. What is the most likely consequence for DNA repair in this patient’s cells?

Accepted Answer

Cells will rely more on nonhomologous end joining, increasing the risk of chromosomal rearrangements.

Question 16

Which of the following best describes a retrotransposon?

Accepted Answer

A transposable element that moves via an RNA intermediate and encodes reverse transcriptase

Question 17

A chemical mutagen causes the loss of a purine base from DNA. What is this process called?

Accepted Answer

Depurination

Question 18

Which of the following is a likely result of a frameshift mutation?

Accepted Answer

The reading frame is altered, changing all downstream amino acids.

Question 19

Which DNA repair mechanism uses a sister chromatid as a template to accurately repair double-strand breaks?

Accepted Answer

Homologous recombination

Question 20

A suppressor mutation occurs in a different gene than the original mutation. What is this type of suppressor mutation called?

Accepted Answer

Intergenic suppressor

Gene Mutations and DNA Repair: Structured Study Notes for Genetics

Study Guide - Practice Questions

Study Guide - Flashcards