Question 1

Which enzyme is responsible for relieving supercoiling ahead of the replication fork during DNA replication in bacteria?

Accepted Answer

Gyrase

Question 2

A DNA strand has the sequence 5'-ATGCGT-3'. What is the complementary RNA sequence produced during transcription?

Accepted Answer

5'-UACGCA-3'

Question 3

Which of the following best describes the difference between the leading and lagging strands during DNA replication?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.

Question 4

Which of the following mutations is most likely to result in a truncated protein?

Accepted Answer

Nonsense mutation

Question 5

A bacterial cell is exposed to UV light, which causes the formation of thymine dimers. Which DNA repair mechanism is most likely to fix this damage?

Accepted Answer

Excision repair

Question 6

Which of the following statements about operons is TRUE?

Accepted Answer

Operons allow bacteria to regulate multiple genes with a single promoter, providing efficient gene regulation.

Question 7

Which of the following microbes uses reverse transcription as part of its replication cycle?

Accepted Answer

HIV

Question 8

In Griffith’s experiment with S. pneumoniae, what process was demonstrated when non-virulent rough bacteria acquired virulence from heat-killed smooth bacteria?

Accepted Answer

Transformation

Question 9

Which of the following best explains why RNA viruses evolve faster than DNA viruses?

Accepted Answer

RNA polymerases lack proofreading ability, leading to higher mutation rates.

Question 10

Which of the following is NOT a criterion used to classify viruses?

Accepted Answer

Ability to form endospores

Question 11

Antigenic shift in influenza viruses is primarily caused by:

Accepted Answer

Reassortment of genome segments between different viral strains

Question 12

Which of the following best describes the difference between lytic and lysogenic replication in bacteriophages?

Accepted Answer

Lytic replication results in immediate destruction of the host cell, while lysogenic replication involves integration of phage DNA into the host genome.

Question 13

Which of the following is a medically important consequence of phage conversion?

Accepted Answer

Bacteria acquire new virulence factors, such as toxin production.

Question 14

Which of the following methods is commonly used to culture viruses in the laboratory?

Accepted Answer

Chicken embryo eggs

Question 15

Which of the following viruses is considered oncogenic and is associated with cervical cancer?

Accepted Answer

Human papillomavirus (HPV)

Question 16

Which of the following drugs targets viral reverse transcriptase?

Accepted Answer

Zidovudine (AZT)

Question 17

Which of the following best describes prions?

Accepted Answer

Infectious proteins that cause neurodegenerative diseases such as Creutzfeldt-Jakob disease

Question 18

Which of the following stains is used to identify bacteria with waxy cell walls, such as Mycobacterium tuberculosis?

Accepted Answer

Acid-fast stain

Question 19

Which of the following best explains why Gram-positive and Gram-negative bacteria stain differently in the Gram stain?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer that retains crystal violet, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane that does not retain crystal violet after decolorization.

Question 20

Which bacterial arrangement is described by the term 'strepto-'?

Accepted Answer

Chains

Microbiology Module 2 Study Guide – Step-by-Step Guidance

Study Guide - Practice Questions

Study Guide - Flashcards