$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following best describes the function of DNA polymerase during DNA replication?

Accepted Answer

DNA polymerase adds nucleotides to the growing DNA strand and proofreads for errors.

Question 2

In the context of the central dogma of molecular biology, which sequence correctly represents the flow of genetic information?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 3

A frameshift mutation is most likely to result from which of the following?

Accepted Answer

The insertion or deletion of one or more nucleotide pairs.

Question 4

Which enzyme is responsible for relaxing supercoiling ahead of the replication fork during DNA replication?

Accepted Answer

DNA gyrase

Question 5

In bacteria, what is the significance of simultaneous transcription and translation?

Accepted Answer

It enables rapid protein synthesis since mRNA is available to ribosomes before transcription is complete.

Question 6

Which of the following statements about the lac operon is correct?

Accepted Answer

The lac operon is induced when allolactose binds to the repressor, preventing it from binding to the operator.

Question 7

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that results in a change in one amino acid.

Question 8

What is the role of cAMP in catabolite repression of the lac operon?

Accepted Answer

cAMP binds to CAP, which then binds to the promoter and enhances transcription when glucose is scarce.

Question 9

Which of the following is a mechanism of horizontal gene transfer in bacteria?

Accepted Answer

Transfer of DNA via conjugation, transformation, or transduction.

Question 10

Which of the following best explains why bacterial DNA replication is highly accurate?

Accepted Answer

DNA polymerase has proofreading capabilities that correct errors during replication.

Question 11

A scientist exposes bacteria to UV radiation. Which repair mechanism is most likely to fix the resulting thymine dimers?

Accepted Answer

Photolyase (light-repair enzyme)

Question 12

Which of the following is true about plasmids in bacteria?

Accepted Answer

Plasmids are circular DNA molecules that may carry genes for antibiotic resistance.

Question 13

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

Accepted Answer

The protein is truncated due to the introduction of a stop codon.

Question 14

Which of the following best describes the function of snRNPs in eukaryotic cells?

Accepted Answer

snRNPs remove introns and splice exons together in mRNA processing.

Question 15

Which of the following is an example of positive regulation of gene expression in bacteria?

Accepted Answer

The binding of cAMP-CAP complex to the promoter to enhance transcription of the lac operon.

Question 16

Which of the following statements about genetic recombination is correct?

Accepted Answer

Genetic recombination involves the exchange of genes between two DNA molecules, increasing genetic diversity.

Question 17

Which of the following best describes the function of microRNAs (miRNAs) in gene regulation?

Accepted Answer

miRNAs bind to mRNA, making it double-stranded and targeting it for enzymatic destruction.

Question 18

Which of the following is a correct description of the function of the operator in an operon?

Accepted Answer

The operator is the site where repressors bind to control transcription of structural genes.

Question 19

Which of the following best explains the effect of a nucleoside analog mutagen?

Accepted Answer

It is structurally similar to normal bases and incorporates into DNA, causing mistakes in base pairing.

Microbial Genetics: Structure, Function, and Regulation of Genetic Material

Study Guide - Practice Questions