Q: Which equation correctly represents the surface area-to-volume ratio for a cube-shaped cell, and why is this ratio important for prokaryotes?

$$\frac{\text{Surface Area}}{\text{Volume}} = \frac{6a^2$}{a^3$}$$; a higher ratio allows for more efficient nutrient exchange.

Question 1

Which of the following statements best describes a key difference between bacterial and archaeal plasma membranes?

Accepted Answer

Archaeal plasma membranes contain long-branched fatty acids, while bacterial membranes contain linear fatty acids.

Question 2

A Gram-negative bacterium is more resistant to certain antibiotics than a Gram-positive bacterium. Which structural feature is primarily responsible for this increased resistance?

Accepted Answer

Outer membrane containing porins

Question 3

Which of the following best explains why prokaryotic cells are generally small (0.5–2.0 μm in diameter)?

Accepted Answer

Smaller cells maximize the surface area-to-volume ratio, facilitating efficient nutrient diffusion.

Question 4

A patient is diagnosed with tuberculosis, caused by Mycobacterium tuberculosis. Which staining method would be most appropriate for identifying this bacterium, and why?

Accepted Answer

Acid-fast stain, because Mycobacterium contains mycolic acid in its cell wall.

Question 5

Which of the following prokaryotic structures is primarily involved in gene transfer between cells?

Accepted Answer

Pili

Question 6

A bacterium is described as pleomorphic. What does this mean, and how might it benefit the organism?

Accepted Answer

It can take on different shapes, enhancing survival and transmission to new hosts.

Question 7

Which equation correctly represents the surface area-to-volume ratio for a cube-shaped cell, and why is this ratio important for prokaryotes?

Accepted Answer

$$\frac{	ext{Surface Area}}{	ext{Volume}} = \frac{6a^2$}{a^3$}$$; a higher ratio allows for more efficient nutrient exchange.

Question 8

Which of the following is TRUE regarding endospore formation in bacteria?

Accepted Answer

Endospores are metabolically inactive structures that allow survival during environmental stress.

Question 9

Which of the following genera are known for producing medically important endospores?

Accepted Answer

Bacillus and Clostridium

Question 10

A Gram-positive bacterium is found to survive better in dry environments than a Gram-negative bacterium. Which feature most likely explains this observation?

Accepted Answer

Thick peptidoglycan layer

Question 11

Which of the following best describes the function of teichoic acids in Gram-positive bacteria?

Accepted Answer

They stabilize the cell wall, help maintain shape, transport cations, and aid in cell division regulation.

Question 12

A researcher observes a bacterium with a single flagellum at one pole. What is the correct term for this flagellar arrangement?

Accepted Answer

Monotrichous

Question 13

Which of the following structures allows prokaryotes to form biofilms by adhering to surfaces and each other?

Accepted Answer

Fimbriae

Question 14

Which of the following statements about Mycoplasma species is correct?

Accepted Answer

They lack a cell wall and have a sterol-enriched plasma membrane.

Question 15

Which of the following is a function of the prokaryotic cytoskeleton?

Accepted Answer

Providing structural support and shape to the cell

Question 16

A bacterium is observed to move toward a nutrient source. Which term best describes this type of movement?

Accepted Answer

Chemotaxis

Question 17

Which of the following best describes the nucleoid region in prokaryotic cells?

Accepted Answer

It is a region containing a single circular chromosome not surrounded by a membrane.

Question 18

Which of the following statements about bacterial ribosomes is correct?

Accepted Answer

They are 70S ribosomes composed of 50S and 30S subunits.

Question 19

Which of the following is TRUE regarding the glycocalyx in prokaryotes?

Accepted Answer

The capsule is a well-organized, tightly associated glycocalyx that aids in adhesion and protection.

Question 20

Which of the following best explains why acid-fast bacteria require long drug therapies?

Accepted Answer

Their waxy cell wall containing mycolic acid prevents rapid drug penetration.

Prokaryotes: Structure, Function, and Clinical Relevance

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