Question 1

Which of the following statements best describes the main structural difference between prokaryotic and eukaryotic cells?

Accepted Answer

Prokaryotic cells have one circular chromosome not enclosed in a membrane, while eukaryotic cells have paired chromosomes within a nuclear membrane.

Question 2

A bacterium is observed to be rod-shaped and arranged in chains. What is the correct term for this arrangement?

Accepted Answer

Streptobacilli

Question 3

Which component of the bacterial cell wall is targeted by the enzyme lysozyme?

Accepted Answer

Disaccharide backbone of peptidoglycan

Question 4

A Gram-negative bacterium is more resistant to antibiotics because:

Accepted Answer

Its outer membrane contains porins and lipopolysaccharides that restrict entry of harmful substances.

Question 5

Which of the following best explains why Mycobacterium species are acid-fast?

Accepted Answer

Their cell walls contain waxy mycolic acids bound to peptidoglycan.

Question 6

Which structure allows bacteria to attach to surfaces and is often involved in the formation of biofilms?

Accepted Answer

Fimbriae

Question 7

A patient is infected with a bacterium that is resistant to desiccation, heat, and chemicals. Which structure is most likely responsible for this resistance?

Accepted Answer

Endospore

Question 8

Which of the following is a function of the plasma membrane in both prokaryotic and eukaryotic cells?

Accepted Answer

Selective permeability

Question 9

During the Gram stain procedure, what is the primary reason that Gram-negative bacteria lose the crystal violet-iodine complex during the alcohol wash?

Accepted Answer

Alcohol dissolves the outer membrane and leaves holes in the thin peptidoglycan layer.

Question 10

Which of the following best describes the movement of water across a selectively permeable membrane from an area of high water concentration to an area of low water concentration?

Accepted Answer

Osmosis

Question 11

A bacterium with peritrichous flagella is placed in a chemical gradient. Which process describes its movement toward an attractant?

Accepted Answer

Taxis

Question 12

Which of the following is NOT a characteristic of Gram-positive bacterial cell walls?

Accepted Answer

Outer membrane containing lipopolysaccharides

Question 13

Which of the following structures is responsible for the transfer of DNA from one bacterial cell to another during conjugation?

Accepted Answer

Pili

Question 14

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 thick peptidoglycan layer that is the target of penicillin.

Question 15

Which of the following is a unique feature of eukaryotic cells compared to prokaryotic cells?

Accepted Answer

Presence of membrane-bound organelles

Question 16

A bacterium is placed in a hypotonic solution. What is the most likely outcome if its cell wall is damaged?

Accepted Answer

The cell will burst due to osmotic lysis.

Question 17

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

Accepted Answer

Prevents phagocytosis and aids in attachment to surfaces

Question 18

Which of the following best describes the composition of peptidoglycan?

Accepted Answer

Polymer of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) linked by polypeptides

Question 19

Which of the following is a function of the Golgi complex in eukaryotic cells?

Accepted Answer

Membrane formation and secretion

Question 20

Which of the following statements about endospores is TRUE?

Accepted Answer

Endospores are resistant to desiccation, heat, and chemicals, and are formed by genera such as Bacillus and Clostridium.

Functional Anatomy of Prokaryotic and Eukaryotic Cells: Microbiology Study Guide

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