Question 1

Which of the following statements best describes the difference between prokaryotic and eukaryotic chromosomes?

Accepted Answer

Prokaryotes have a single, supercoiled circular chromosome, while eukaryotes have multiple linear chromosomes.

Question 2

Which structure is unique to Gram-negative bacteria and acts as a barrier to many antimicrobial compounds?

Accepted Answer

Outer membrane containing lipopolysaccharides (LPS)

Question 3

A bacterium is observed to have a single flagellum at each end. What is the correct term for this flagellar arrangement?

Accepted Answer

Amphitrichous

Question 4

Which of the following is a function of the glycocalyx in bacteria?

Accepted Answer

Formation of biofilms and protection from dehydration

Question 5

During the Gram stain procedure, what is the most important step for differentiating Gram-positive from Gram-negative bacteria?

Accepted Answer

Decolorization with alcohol or acetone

Question 6

Which component of the bacterial cell wall is targeted by lysozyme, leading to cell lysis?

Accepted Answer

Peptidoglycan at the $$\beta-1$$,4 linkage between N-acetylglucosamine and N-acetylmuramic acid

Question 7

Which of the following is NOT a function of bacterial pili?

Accepted Answer

Motility

Question 8

A patient is infected with a bacterium that releases lipid A, causing fever and shock. Which structure is responsible?

Accepted Answer

Lipopolysaccharide (LPS) in the outer membrane

Question 9

Which of the following best describes the ribosomes found in prokaryotic cells?

Accepted Answer

70S ribosomes composed of 50S and 30S subunits

Question 10

Which bacterial structure is primarily responsible for the formation of biofilms and increased resistance to phagocytosis?

Accepted Answer

Glycocalyx (capsule or slime layer)

Question 11

Which of the following statements about endospores is TRUE?

Accepted Answer

Endospores are metabolically inactive and highly resistant to environmental stress.

Question 12

Which of the following is a major difference between Gram-positive and Gram-negative cell walls?

Accepted Answer

Gram-positive cell walls contain teichoic acids and a thick peptidoglycan layer.

Question 13

Which bacterial cell envelope structure is most likely to be targeted by antibiotics such as penicillin?

Accepted Answer

Peptidoglycan

Question 14

A bacterium with no cell wall but a cell membrane stabilized by sterols is most likely:

Accepted Answer

A Mycoplasma species

Question 15

Which of the following is a function of the bacterial cytoskeleton?

Accepted Answer

Cell shape, division, and movement of materials

Question 16

Which of the following best describes the process of conjugation in bacteria?

Accepted Answer

Transfer of a copy of plasmid DNA via conjugation pili

Question 17

Which of the following is a major function of porin proteins in Gram-negative bacteria?

Accepted Answer

Regulation of materials entering and leaving the cell

Question 18

Which bacterial structure is most likely to be involved in chemotaxis?

Accepted Answer

Flagella

Question 19

Which of the following statements about plasmids is TRUE?

Accepted Answer

Plasmids are small, circular, double-stranded DNA molecules that can be exchanged between bacteria.

Question 20

Which of the following best describes the fluid mosaic model of the bacterial cell membrane?

Accepted Answer

A phospholipid bilayer with embedded proteins that allows selective permeability

Microbial Cell Structures: Prokaryotic and Eukaryotic Cells, Bacterial Cell Envelopes, and Specialized Structures

Study Guide - Practice Questions