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

$$\text{Surface area-to-volume ratio} = \frac{\text{Surface area}}{\text{Volume}}$$

Question 1

Which of the following statements best explains why most prokaryotic cells are small in size?

Accepted Answer

Their small size increases the surface area-to-volume ratio, enhancing diffusion of nutrients and waste.

Question 2

Which prokaryotic domain contains organisms with long-branched fatty acids in their plasma membranes, and what is a key difference from the other domain?

Accepted Answer

Archaea; they can have lipid monolayers instead of bilayers.

Question 3

A bacterium is placed in a hypertonic solution. What is the most likely outcome for the cell?

Accepted Answer

The cell will lose water, and plasmolysis may occur.

Question 4

Which bacterial structure is responsible for motility and is powered by ATP, rotating like a propeller?

Accepted Answer

Flagella

Question 5

Which arrangement describes bacteria forming chains of rod-shaped cells?

Accepted Answer

Streptobacilli

Question 6

Gram-negative bacteria are typically harder to kill with chemical agents than Gram-positive bacteria. Which structural feature is primarily responsible for this?

Accepted Answer

The presence of an outer membrane containing lipopolysaccharide (LPS)

Question 7

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

Accepted Answer

DNA is replicated, the cell elongates, a septum forms, and two daughter cells are separated.

Question 8

Which of the following is a clinically significant implication of acid-fast bacteria, such as Mycobacterium tuberculosis?

Accepted Answer

They require long, multi-drug therapies due to their slow growth and waxy cell wall.

Question 9

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

Accepted Answer

$$	ext{Surface area-to-volume ratio} = \frac{	ext{Surface area}}{	ext{Volume}}$$

Question 10

Which structure allows bacteria to adhere to surfaces and each other, and is especially common in Gram-negative bacteria?

Accepted Answer

Fimbriae

Question 11

A patient is infected with Clostridioides difficile. Which property of this bacterium makes it particularly challenging to control in healthcare settings?

Accepted Answer

It forms endospores that survive for extended periods on surfaces.

Question 12

Which of the following best describes the function of the prokaryotic ribosome, and why is its size clinically relevant?

Accepted Answer

It synthesizes proteins; its 70S size allows certain antibiotics to target bacteria without affecting eukaryotic cells.

Question 13

Which transport mechanism involves the movement of water across a membrane from areas of low solute concentration to areas of high solute concentration?

Accepted Answer

Osmosis

Question 14

Which bacterial structure is a sticky carbohydrate-rich layer that can protect against antibiotics and desiccation, and what are its two forms?

Accepted Answer

Glycocalyx; slime layer and capsule

Question 15

Which of the following is NOT a function of membrane proteins in prokaryotic plasma membranes?

Accepted Answer

DNA replication

Question 16

Which type of active transport in prokaryotes uses an ion gradient to drive the movement of substances, and what are the two main types?

Accepted Answer

Secondary active transport; symport and antiport

Question 17

Which bacterial genus lacks a cell wall, is pleomorphic, and is the causative agent of 'walking pneumonia'?

Accepted Answer

Mycoplasma

Question 18

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

Accepted Answer

A cytoplasmic region containing a single circular chromosome of double-stranded DNA

Question 19

Which structure is used by bacteria to transfer DNA from cell to cell, spreading antibiotic resistance genes?

Accepted Answer

Conjugation pilus

Question 20

Which of the following is a property of L-forms, and why are they clinically significant?

Accepted Answer

They are bacteria that lost their cell wall, making them resistant to antibiotics targeting cell wall structures.

Prokaryotic Cell Structure and Function: Microbiology Study Guide

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