Question 1

Which of the following best explains why different cell types in the human body can have distinct functions despite having identical DNA?

Accepted Answer

Because different cell types express different sets of genes (differential gene expression).

Question 2

What is the effect of DNA methylation on chromatin structure and gene transcription?

Accepted Answer

DNA methylation causes chromatin to pack, decreasing gene transcription.

Question 3

Which of the following is TRUE regarding histone acetylation?

Accepted Answer

Histone acetylation leads to decondensed chromatin and increased gene transcription.

Question 4

Epigenetic inheritance refers to:

Accepted Answer

The inheritance of chromatin modifications, such as DNA methylation and histone acetylation, through cell division.

Question 5

Which of the following best describes the role of activator proteins in transcription?

Accepted Answer

Activator proteins bind to enhancer regions and increase transcription.

Question 6

A repressor protein binds to a silencer region of DNA. What is the expected outcome?

Accepted Answer

Transcription of the associated gene will decrease.

Question 7

Alternative splicing allows a single gene to:

Accepted Answer

Produce multiple proteins by removing introns in different ways.

Question 8

MicroRNAs regulate gene expression by:

Accepted Answer

Binding to mRNA and either degrading it or blocking its translation.

Question 9

Which of the following is a consequence of a nonsense mutation in a gene?

Accepted Answer

A stop codon is introduced prematurely, resulting in a truncated protein.

Question 10

A frameshift mutation is most likely to occur when:

Accepted Answer

One or two nucleotides are inserted or deleted, altering the reading frame.

Question 11

Given the following original DNA sequence: $$3'\ ATA\ ACC\ GAT\ CAT\ CT...\ 5'$$ and its mRNA: $$5'\ UAU\ UGG\ CUA\ GUA\ CA...\ 3'$$, what type of mutation would result if the codon $$UGG is $$changed to $$UGA$$?

Accepted Answer

Nonsense mutation

Question 12

Which of the following statements about silent mutations is correct?

Accepted Answer

Silent mutations do not change the amino acid sequence due to redundancy in the genetic code.

Question 13

A patient inherits a chromatin modification that keeps a tumor suppressor gene permanently packed and silenced. What is the most likely mechanism?

Accepted Answer

Epigenetic inheritance of DNA methylation.

Question 14

Which process is most directly responsible for the inheritance of chromatin modifications during cell division?

Accepted Answer

Epigenetic inheritance

Question 15

If a microRNA binds perfectly to its target mRNA, what is the expected outcome?

Accepted Answer

The mRNA is cut and rapidly degraded.

Question 16

Which of the following best describes the relationship between chromatin structure and transcription?

Accepted Answer

Decondensed chromatin allows transcription to occur.

Question 17

A mutation changes a hydrophobic amino acid to a hydrophilic one in a protein. What type of mutation is this, and what is a possible consequence?

Accepted Answer

Missense mutation; it may alter protein folding and function.

Question 18

Which of the following scenarios would most likely result in a frameshift mutation?

Accepted Answer

Deletion of one nucleotide from a coding region.

Question 19

Which of the following is NOT a level at which eukaryotic gene expression is regulated?

Accepted Answer

DNA replication

Regulation of Gene Expression in Eukaryotes and the Effect of Genetic Mutations

Study Guide - Practice Questions

Study Guide - Flashcards