Question 1

Which of the following statements correctly describes a key difference between the two prokaryotic domains, Bacteria and Archaea?

Accepted Answer

Archaea have unique membrane lipids with ether bonds, while Bacteria have ester-linked membrane lipids.

Question 2

Which of the following is an extracellular structure found in prokaryotes that aids in attachment to surfaces and evasion of the host immune system?

Accepted Answer

Capsule

Question 3

What is the average diameter of a typical prokaryotic cell?

Accepted Answer

$$0.5-5\ \mu m$$

Question 4

A Gram-positive bacterium is more susceptible to which of the following due to its cell wall structure?

Accepted Answer

Lysozyme digestion

Question 5

Which passive transport mechanism allows water to move across a prokaryotic cell membrane in response to solute concentration gradients?

Accepted Answer

Osmosis

Question 6

A bacterial cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

The cell will lose water and shrink (plasmolysis).

Question 7

Which structure is primarily responsible for bacterial motility?

Accepted Answer

Flagellum

Question 8

How do periplasmic flagella benefit spirochetes in terms of movement and survival?

Accepted Answer

They enable corkscrew motion, allowing movement through viscous environments.

Question 9

Which statement best describes the organization of DNA in prokaryotic cells?

Accepted Answer

DNA is organized in a nucleoid region without a surrounding membrane.

Question 10

During prokaryotic cell division, how is DNA replication coordinated with cell growth?

Accepted Answer

DNA replication and cell division are tightly coupled, often overlapping to allow rapid growth.

Question 11

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

Accepted Answer

Storage of genetic material

Question 12

Bacterial endospores are medically important because:

Accepted Answer

They allow bacteria to survive extreme conditions, including heat and desiccation.

Question 13

Which of the following bacteria is known for producing endospores that cause disease in humans?

Accepted Answer

Bacillus anthracis

Question 14

Why are antibiotics that target peptidoglycan synthesis generally ineffective against human cells?

Accepted Answer

Human cells lack peptidoglycan in their cell walls.

Question 15

Which antibiotic mechanism specifically targets bacterial ribosomes, inhibiting protein synthesis?

Accepted Answer

Tetracycline binding to the 30S ribosomal subunit

Question 16

A patient is infected with a Gram-negative bacterium. Which structural feature makes this bacterium more resistant to certain antibiotics?

Accepted Answer

Presence of an outer membrane containing lipopolysaccharides

Question 17

Which of the following best explains why Gram-positive bacteria stain purple in the Gram stain procedure?

Accepted Answer

They have a thick peptidoglycan layer that traps the crystal violet-iodine complex.

Question 18

Which process is used by bacteria to actively transport nutrients against a concentration gradient?

Accepted Answer

Active transport using ATP

Question 19

A Gram-negative bacterium is exposed to detergents. What is the most likely effect on its cell envelope?

Accepted Answer

Disruption of the outer membrane, increasing permeability

Question 20

Which of the following best describes the role of pili in prokaryotic cells?

Accepted Answer

Attachment to surfaces and DNA transfer during conjugation

Fundamental Concepts in Prokaryotic Microbiology: Structure, Function, and Comparison

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