Question 1

Which of the following is a key difference between prokaryotic and eukaryotic cells?

Accepted Answer

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have both.

Question 2

A bacterium is found to have a thick peptidoglycan layer and teichoic acids in its cell wall. After Gram staining, what color will it appear and why?

Accepted Answer

Purple, because the thick peptidoglycan layer retains the crystal violet-iodine complex.

Question 3

Which structure is responsible for bacterial motility and consists of a filament, hook, and basal body?

Accepted Answer

Flagella

Question 4

A scientist observes a cell with a single, circular DNA molecule, 70S ribosomes, and a cell wall lacking peptidoglycan. This cell is most likely:

Accepted Answer

An archaeal cell

Question 5

Which of the following best describes the function of the bacterial glycocalyx capsule?

Accepted Answer

It prevents recognition by the host immune system and aids in attachment.

Question 6

Which process involves the movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration?

Accepted Answer

Osmosis

Question 7

A bacterium is placed in a hypertonic solution. What will most likely happen to the cell?

Accepted Answer

It will lose water and undergo plasmolysis.

Question 8

Which of the following is true regarding group translocation in bacteria?

Accepted Answer

The transported substance is chemically modified during passage across the membrane.

Question 9

Which of the following structures is found in both prokaryotic and eukaryotic cells and is the site of protein synthesis?

Accepted Answer

Ribosome

Question 10

A patient is infected with a Gram-negative bacterium. Which component of the bacterial cell wall may contribute to the severity of the infection?

Accepted Answer

Lipopolysaccharide (LPS)

Question 11

Which of the following equations best represents the process of osmosis?

Accepted Answer

$$J = -L_p (\Delta P - \sigma \Delta \pi)$$

Question 12

Which of the following statements about eukaryotic flagella is correct?

Accepted Answer

They are anchored by a basal body and undulate rhythmically.

Question 13

Which of the following is a function of the eukaryotic Golgi body?

Accepted Answer

Processing and packaging molecules for export

Question 14

A bacterial cell is observed to have a single pilus. What is the most likely function of this structure?

Accepted Answer

Transfer of DNA during conjugation

Question 15

Which of the following best explains why antibiotics that target peptidoglycan are effective against bacteria but not human cells?

Accepted Answer

Bacterial cells have peptidoglycan in their cell walls, while human cells do not.

Question 16

Which of the following is NOT a function of the prokaryotic cytoplasmic membrane?

Accepted Answer

Protein synthesis

Question 17

Which of the following statements about endospores is correct?

Accepted Answer

They are resistant structures formed by some bacteria as a defensive strategy.

Question 18

Which of the following is a unique feature of archaeal cell walls compared to bacterial cell walls?

Accepted Answer

Presence of specialized polysaccharides and proteins

Question 19

According to the endosymbiotic theory, which organelle is believed to have originated from an aerobic prokaryote?

Accepted Answer

Mitochondrion

Question 20

Which of the following best describes the arrangement of microtubules in a eukaryotic flagellum?

Accepted Answer

9+2 arrangement of microtubules

Cell Structure and Function in Microbiology

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