Question 1

Which of the following best explains why small prokaryotic cells have a higher metabolic efficiency compared to larger cells?

Accepted Answer

They have a higher surface area-to-volume ratio, allowing greater nutrient and waste exchange per unit cell volume. 
$	ext{Surface Area to Volume Ratio} = \frac{	ext{Surface Area}}{	ext{Volume}}$

Question 2

A bacterium is observed to have a thick peptidoglycan layer, teichoic acids, and no outer membrane. Which type of cell wall does it most likely possess?

Accepted Answer

Gram-positive cell wall

Question 3

Which of the following is a function of the bacterial S-layer?

Accepted Answer

Providing osmotic protection and acting as a molecular sieve

Question 4

A scientist isolates a prokaryote with ether-linked membrane lipids and isoprenoid side chains. Which domain does this organism most likely belong to?

Accepted Answer

Archaea

Question 5

Which of the following statements about Gram-negative bacteria is correct?

Accepted Answer

Their outer membrane contains lipopolysaccharide (LPS), which contributes to pathogenicity.

Question 6

Which structure is responsible for the resistance of bacterial endospores to heat and desiccation?

Accepted Answer

Endospore coat and cortex, which contain peptidoglycan and small acid-soluble spore proteins (SASPs)

Question 7

A bacterium is found to move toward a chemical attractant. Which process is responsible for this behavior?

Accepted Answer

Chemotaxis

Question 8

Which of the following best describes the function of group translocation in bacterial cells?

Accepted Answer

Transport of a substance into the cell while chemically modifying it during passage across the membrane

Question 9

Which of the following is a distinguishing feature of the bacterial nucleoid?

Accepted Answer

It contains a single, circular, double-stranded DNA molecule.

Question 10

A patient is infected with a bacterium that is resistant to penicillin. Which of the following is the most likely explanation for this resistance?

Accepted Answer

The bacterium has a plasmid encoding a gene for beta-lactamase, which degrades penicillin.

Question 11

Which of the following best explains why lysozyme is effective against many bacteria but not Archaea?

Accepted Answer

Lysozyme cleaves the $\beta$-1,4 glycosidic bonds in peptidoglycan, which is absent in Archaea.

Question 12

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

Accepted Answer

Site of ATP synthesis

Question 13

A Gram-negative bacterium is found to be highly resistant to certain antibiotics. Which component of its cell envelope most likely contributes to this resistance?

Accepted Answer

Outer membrane containing porins and lipopolysaccharide (LPS)

Question 14

Which of the following best describes the arrangement of flagella in a peritrichous bacterium?

Accepted Answer

Flagella distributed evenly over the entire cell surface

Question 15

Which of the following inclusion bodies is primarily used for nitrogen storage in cyanobacteria?

Accepted Answer

Cyanophycin granules

Question 16

During sporulation, which event occurs first in the formation of a bacterial endospore?

Accepted Answer

Asymmetric cell division and formation of the forespore

Question 17

Which of the following best explains why the O-antigen of lipopolysaccharide (LPS) is important for bacterial survival in a host?

Accepted Answer

It helps the bacterium evade host immune responses by varying its structure.

Question 18

Which of the following is a key difference between simple transport and ABC transport systems in bacteria?

Accepted Answer

Simple transport uses the proton motive force, while ABC transport uses ATP hydrolysis. 
$	ext{ABC Transport:} \quad 	ext{ATP} ightarrow 	ext{ADP} + 	ext{P}_i$

Question 19

A bacterium is observed to have a single, circular chromosome and several small, closed circular DNA molecules that replicate independently. What are these small DNA molecules called?

Accepted Answer

Plasmids

Question 20

Which of the following best describes the process of germination in bacterial endospores?

Accepted Answer

Activation, breaking of the spore coat, and emergence of a metabolically active cell

Structure and Function of Prokaryotic Cells: Microbiology Study Notes

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