Question 1

Which of the following statements correctly distinguishes between the cell walls of Bacteria and Archaea?

Accepted Answer

Bacterial cell walls contain peptidoglycan, while archaeal cell walls lack peptidoglycan and may contain pseudomurein.

Question 2

A microbiologist isolates a microbe from a hot spring with a cell membrane containing ether linkages and isoprene chains. Which domain does this organism most likely belong to?

Accepted Answer

Domain Archaea

Question 3

Which cell envelope component is found in all prokaryotes and is primarily responsible for selective permeability?

Accepted Answer

Cytoplasmic membrane

Question 4

During Gram staining, which structural difference causes Gram-positive bacteria to retain the crystal violet stain?

Accepted Answer

A thick layer of peptidoglycan stabilized by peptide cross-links

Question 5

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

Accepted Answer

They aid in surface attachment, biofilm formation, and protection against desiccation.

Question 6

A bacterium is observed to have peritrichous flagella. What does this mean?

Accepted Answer

Flagella are distributed all over the cell surface.

Question 7

Which of the following is a function of gas vesicles in aquatic bacteria?

Accepted Answer

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

Question 8

Endospores are highly resistant structures formed by some bacteria. Which of the following is NOT a property of endospores?

Accepted Answer

They are dormant and highly differentiated.

Question 9

Which of the following best explains why Gram-negative bacteria are generally more resistant to antibiotics than Gram-positive bacteria?

Accepted Answer

Gram-negative bacteria possess an outer membrane that acts as a barrier to many antibiotics.

Question 10

Which of the following storage inclusions is synthesized when carbon is in excess and can be broken down for energy when needed?

Accepted Answer

Poly-β-hydroxyalkanoate (PHA)

Question 11

A scientist observes a microbe that migrates along magnetic field lines. Which cellular structure is responsible for this behavior?

Accepted Answer

Magnetosomes

Question 12

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

Accepted Answer

Eukaryotic flagella are composed of microtubules in a 9+2 arrangement and move by a whip-like motion powered by ATP.

Question 13

Which of the following best describes the role of S-layers in Archaea?

Accepted Answer

They provide strength, protection from lysis, and facilitate cell surface interactions.

Question 14

Which of the following structures is involved in genetic exchange between bacterial cells during conjugation?

Accepted Answer

Conjugative pili

Question 15

A Gram-positive bacterium is exposed to lysozyme. What is the most likely outcome?

Accepted Answer

The peptidoglycan layer will be degraded, leading to cell lysis.

Question 16

Which of the following best describes the process of binary fission in prokaryotes?

Accepted Answer

A single cell divides into two genetically identical daughter cells.

Question 17

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

Accepted Answer

Modification and shipping of proteins and other macromolecules.

Question 18

Which equation best represents the oxidation of elemental sulfur to sulfate in bacteria?

Accepted Answer

$$\mathrm{S} + 2\mathrm{O}_2 \rightarrow \mathrm{SO}_4$$^{2-}$$

Question 19

A cell is observed to have a nucleus, mitochondria, and chloroplasts. According to the endosymbiosis theory, which statement is correct?

Accepted Answer

Mitochondria and chloroplasts originated from free-living prokaryotes engulfed by ancestral eukaryotic cells.

Question 20

Which of the following best describes the function of the cytoskeleton in eukaryotic cells?

Accepted Answer

It provides mechanical support, enables cell movement, and organizes cell division.

Microbial Cell Structure and Function: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard