Question 1

Which of the following best distinguishes a capsule from a slime layer in prokaryotes?

Accepted Answer

Capsules are tightly attached with a tight matrix, while slime layers are loosely attached and easily deformed.

Question 2

A researcher observes a prokaryotic cell with a thick, tightly attached layer outside the cell wall that helps the cell evade phagocytosis. What is this structure most likely to be?

Accepted Answer

Capsule

Question 3

Which of the following is NOT a function of polysaccharide layers (capsules and slime layers) in bacteria?

Accepted Answer

Providing significant structural strength to the cell wall

Question 4

Which structure is primarily responsible for twitching motility in some bacteria, and what is the energy source for this movement?

Accepted Answer

Type IV pili; powered by ATP

Question 5

What is the main difference between fimbriae and pili?

Accepted Answer

Pili are typically longer and fewer in number than fimbriae.

Question 6

Which of the following structures is unique to some Archaea and functions to anchor cells to surfaces, forming biofilms?

Accepted Answer

Hami

Question 7

A bacterium is found to accumulate polyphosphate granules. What is the primary function of these inclusions?

Accepted Answer

Reservoir for inorganic phosphate used in nucleic acid and phospholipid synthesis

Question 8

Which of the following best describes the function of gas vesicles in planktonic microbes?

Accepted Answer

They confer buoyancy, allowing cells to position themselves in the water column.

Question 9

A bacterium is observed to orient itself along magnetic field lines. Which structure is responsible for this behavior, and what is the process called?

Accepted Answer

Magnetosomes; magnetotaxis

Question 10

Which of the following is a correct statement about endospores?

Accepted Answer

Endospores are highly resistant, dormant structures formed by some Gram-positive bacteria during unfavorable conditions.

Question 11

Which of the following is NOT a typical step in the germination of a bacterial endospore?

Accepted Answer

Formation of dipicolinic acid and spore coat

Question 12

What is the role of dipicolinic acid and calcium ions in the core of bacterial endospores?

Accepted Answer

They cross-link to reduce water content and increase heat resistance.

Question 13

A microbiologist discovers a bacterium with inclusions that act as ballast, helping the cell maintain its position deep in an aquatic environment. Which type of inclusion is most likely present?

Accepted Answer

Carbonate mineral inclusions (e.g., benstonite)

Question 14

Which of the following best explains why endospores are more resistant to heat than vegetative cells?

Accepted Answer

Endospores contain high levels of dipicolinic acid and calcium, which reduce water content and stabilize macromolecules.

Question 15

Which of the following is a correct sequence of events during the reactivation of a bacterial endospore?

Accepted Answer

Activation → Germination → Outgrowth

Question 16

A patient is infected with a bacterium that forms biofilms on medical devices and resists being washed away. Which structure is most likely responsible for this property?

Accepted Answer

Hami

Question 17

Which of the following inclusions is primarily used by bacteria to store excess carbon?

Accepted Answer

Poly-β-hydroxybutyric acid (PHB)

Question 18

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

Accepted Answer

The formation of carbonate minerals as cellular inclusions

Question 19

A bacterium is found to have inclusions that allow it to orient itself toward sediments in low-oxygen aquatic environments. Which structure is responsible for this behavior?

Accepted Answer

Magnetosomes

Question 20

Which of the following statements about sporulation in Bacillus subtilis is correct?

Accepted Answer

Sporulation involves the expression of over 200 spore-specific genes.

Prokaryotic Cell Surface Structures and Inclusions

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