Question 1

Which of the following statements best describes the main difference between Gram-positive and Gram-negative bacterial cell walls?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane containing LPS.

Question 2

A patient is diagnosed with toxic shock syndrome caused by a bacterial infection. Which component of the bacterial cell wall is most likely responsible for this condition?

Accepted Answer

Lipid A of lipopolysaccharide (LPS)

Question 3

Which bacterial structure is primarily responsible for motility and can be arranged in monotrichous, lophotrichous, amphitrichous, or peritrichous patterns?

Accepted Answer

Flagella

Question 4

A bacterium is found to survive boiling water and harsh disinfectants. Which structure is most likely responsible for this resistance?

Accepted Answer

Endospore

Question 5

Which of the following best describes the function of the glycocalyx in bacteria?

Accepted Answer

It aids in attachment to surfaces and evasion of the immune system.

Question 6

Which of the following antibiotics targets the peptidoglycan layer of bacterial cell walls, making it more effective against Gram-positive bacteria?

Accepted Answer

Penicillin

Question 7

A bacterium is described as pleomorphic. What does this mean?

Accepted Answer

It can change its shape and does not have a single, defined morphology.

Question 8

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

Accepted Answer

Encoding essential genes for cell survival

Question 9

Which group of bacteria is known for nitrogen fixation and includes pathogens such as Rickettsia typhi?

Accepted Answer

Alphaproteobacteria

Question 10

A scientist isolates a bacterium from a hot spring with a temperature of 110°C. The organism lacks peptidoglycan in its cell wall and produces methane. To which domain does this organism most likely belong?

Accepted Answer

Archaea

Question 11

Which of the following best describes the process of osmosis in bacterial cells?

Accepted Answer

Movement of water from high to low concentration of water across a semi-permeable membrane

Question 12

Which of the following bacterial structures is most directly involved in conjugation and horizontal gene transfer?

Accepted Answer

Pilus

Question 13

Which of the following is a distinguishing feature of Mycobacterium species such as M. tuberculosis?

Accepted Answer

Presence of mycolic acid in the cell wall

Question 14

Which of the following best describes the arrangement of Streptococci?

Accepted Answer

Chains of spherical cells

Question 15

A bacterium is found to have axial filaments for movement. Which group does it most likely belong to?

Accepted Answer

Spirochetes

Question 16

Which of the following is true regarding the function of fimbriae in bacteria?

Accepted Answer

They are used for attachment to surfaces.

Question 17

Which of the following best explains why penicillin is more effective against Gram-positive bacteria than Gram-negative bacteria?

Accepted Answer

Gram-positive bacteria have a thicker peptidoglycan layer that is more accessible to penicillin.

Question 18

Which of the following is a characteristic of Archaea but NOT Bacteria?

Accepted Answer

Ability to live in extreme environments such as high salinity or temperature

Question 19

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

Accepted Answer

Protein synthesis

Question 20

A patient presents with a bacterial infection that is resistant to boiling and many disinfectants. The causative agent is most likely to be which of the following?

Accepted Answer

A spore-forming bacterium such as Clostridium difficile

The Prokaryotes: Structure, Function, and Diversity

Study Guide - Practice Questions

Study Guide - Flashcards