Question 1

Which of the following statements best describes a key structural difference between bacterial and archaeal plasma membranes?

Accepted Answer

Bacterial plasma membranes contain linear fatty acids, while archaeal membranes contain long-branched fatty acids.

Question 2

A clinical microbiologist observes spherical bacteria arranged in chains from a throat culture. Which term best describes this arrangement?

Accepted Answer

Streptococci

Question 3

Which component is unique to Gram-negative bacteria and contributes to their increased resistance to chemical agents?

Accepted Answer

Outer membrane containing lipopolysaccharide (LPS)

Question 4

Which of the following best explains why prokaryotic cells are limited in size?

Accepted Answer

Their nutrients are obtained primarily through diffusion, which is limited by the surface area-to-volume ratio.

Question 5

Which of the following is the correct sequence of events in binary fission?

Accepted Answer

DNA is copied, cell elongates, copied chromosome is drawn to opposite ends, septum forms, daughter cells separate

Question 6

Which of the following best describes the function of the bacterial capsule?

Accepted Answer

It helps bacteria adhere to surfaces and protects against desiccation and some antibiotics.

Question 7

A bacterium is placed in a hypertonic solution. What is the most likely outcome for the cell?

Accepted Answer

The cell will lose water, resulting in plasmolysis.

Question 8

Which of the following transport mechanisms requires energy and can move substances against their concentration gradient?

Accepted Answer

Active transport

Question 9

Which structure is responsible for the corkscrew motility observed in spirochetes?

Accepted Answer

Periplasmic flagella (axial filaments)

Question 10

Which of the following statements about endospores is TRUE?

Accepted Answer

Endospores are highly resistant structures that allow certain bacteria to survive harsh conditions.

Question 11

Which of the following best describes the composition of peptidoglycan in bacterial cell walls?

Accepted Answer

Alternating N-acetyl-D-glucosamine (NAG) and N-acetylmuramic acid (NAM) residues cross-linked by peptides

Question 12

Which of the following is a medically important Gram-positive, nonmotile, encapsulated bacterium that causes streptococcal pharyngitis?

Accepted Answer

Streptococcus pyogenes

Question 13

Which of the following statements about acid-fast bacteria is correct?

Accepted Answer

They have a waxy cell wall containing mycolic acid, which makes them resistant to many drugs.

Question 14

Which of the following best describes the function of fimbriae in prokaryotic cells?

Accepted Answer

Adhesion to surfaces and biofilm formation

Question 15

Which of the following is NOT a function of the prokaryotic plasma membrane?

Accepted Answer

Site of DNA replication

Question 16

Which of the following best explains why penicillin is generally effective against Streptococcus pyogenes?

Accepted Answer

Penicillin interferes with peptidoglycan synthesis, which is abundant in Gram-positive bacteria like S. pyogenes.

Question 17

Which of the following is a correct statement about the nucleoid region in prokaryotic cells?

Accepted Answer

It contains the cell's circular chromosome.

Question 18

Which of the following best describes the difference between simple diffusion and facilitated diffusion?

Accepted Answer

Facilitated diffusion requires membrane proteins, while simple diffusion does not.

Question 19

Which of the following structures is NOT typically found in Archaea?

Accepted Answer

Peptidoglycan in the cell wall

Question 20

A bacterium is observed to have a tuft of flagella at one pole. What is the correct term for this flagellar arrangement?

Accepted Answer

Lophotrichous

Chapter 3

Study Guide - Practice Questions