Question 1

Which of the following best explains why Mycoplasma pneumoniae is resistant to antibiotics like penicillin?

Accepted Answer

It lacks a cell wall, so penicillin has no target to act upon.

Question 2

A hospital patient develops a blue-green wound infection after surgery. Which bacterium is most likely responsible, and what is a key identifying feature?

Accepted Answer

Pseudomonas aeruginosa; production of blue-green pigments

Question 3

Which of the following statements about the lysogenic cycle of bacteriophages is CORRECT?

Accepted Answer

The phage DNA integrates into the host chromosome and is replicated with the host genome.

Question 4

Which of the following best describes the function of Okazaki fragments during DNA replication?

Accepted Answer

They are short DNA fragments synthesized on the lagging strand and later joined by DNA ligase.

Question 5

A patient presents with severe watery diarrhea after drinking contaminated water. Laboratory tests identify a curved, Gram-negative bacterium. Which organism is most likely responsible?

Accepted Answer

Vibrio cholerae

Question 6

Which of the following is a key difference between fungi and bacteria?

Accepted Answer

Fungi have sterols in their cell membranes, while bacteria generally do not.

Question 7

Which of the following best describes the role of reverse transcriptase in retroviruses?

Accepted Answer

It copies viral RNA into complementary DNA ($$cDNA).$$

Question 8

Which of the following is an example of horizontal gene transfer in bacteria?

Accepted Answer

A bacterium acquiring a plasmid through conjugation via a sex pilus.

Question 9

Which of the following is TRUE regarding the function of cyanobacteria in Earth's history?

Accepted Answer

They performed oxygenic photosynthesis, significantly increasing atmospheric oxygen.

Question 10

A patient with AIDS develops a chronic eye infection caused by a fungus that lacks mitochondria and is an obligate intracellular parasite. Which group does this fungus belong to?

Accepted Answer

Microsporidia

Question 11

Which of the following best explains why Cryptosporidium outbreaks can occur in chlorinated swimming pools?

Accepted Answer

Cryptosporidium is a protozoan with a cyst form that is resistant to chlorine.

Question 12

Which of the following is a correct pairing of a disease and its causative agent?

Accepted Answer

Whooping cough — Bordetella pertussis

Question 13

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

Accepted Answer

It is an inducible operon that is turned ON in the presence of lactose.

Question 14

Which of the following best describes the process of specialized transduction?

Accepted Answer

Specific bacterial genes are transferred by a lysogenic phage when the prophage is excised.

Question 15

Which of the following is a function of the viral envelope?

Accepted Answer

It is derived from the host cell membrane and helps the virus enter new host cells.

Question 16

A mutation changes a DNA codon from $$	ext{GAA} ($$glutamic acid) to $$	ext{GAG} ($$also glutamic acid). What type of mutation is this?

Accepted Answer

Silent mutation

Question 17

Which of the following best explains why E. coli is used as an indicator organism for water contamination?

Accepted Answer

It is commonly found in the intestinal tract and its presence indicates fecal contamination.

Question 18

Which of the following is a characteristic of facultative anaerobes?

Accepted Answer

They can grow with or without oxygen.

Question 19

Which of the following is a correct description of the function of tRNA during translation?

Accepted Answer

It brings specific amino acids to the ribosome and matches them to the mRNA codon via its anticodon.

Question 20

Which of the following best describes the role of snRNPs (spliceosome) in eukaryotic gene expression?

Accepted Answer

They remove introns from pre-mRNA, joining exons together.

Comprehensive Study Notes: Prokaryotes, Eukaryotic Microorganisms, Viruses, and Microbial Genetics

Study Guide - Practice Questions

Study Guide - Flashcards