Question 1

Which of the following is a key structural difference between Gram-positive and Gram-negative bacterial cell envelopes?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer and lack an outer membrane.

Question 2

Which of the following best explains why prokaryotes are generally so small?

Accepted Answer

Their small size increases the surface area-to-volume ratio, facilitating efficient nutrient uptake and waste removal.

Question 3

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

Accepted Answer

Water will leave the cell, causing plasmolysis.

Question 4

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

Accepted Answer

They allow bacteria to survive extreme environmental conditions such as heat, desiccation, and chemicals.

Question 5

Which structure is responsible for bacterial motility and how does it benefit the cell?

Accepted Answer

Flagella; they enable movement toward nutrients and away from harmful substances, increasing survival.

Question 6

Which of the following statements about passive and active transport in prokaryotic cells is correct?

Accepted Answer

Active transport requires energy input, while passive transport relies on concentration gradients.

Question 7

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

Accepted Answer

Human cells lack peptidoglycan in their cell walls, so these antibiotics do not affect them.

Question 8

Which of the following is a function of thylakoids in prokaryotic cells?

Accepted Answer

They are involved in photosynthesis by housing pigments and electron transport chains.

Question 9

A patient is infected with Bacillus anthracis, a bacterium known to form endospores. Why is this infection particularly difficult to eradicate?

Accepted Answer

Endospores are highly resistant to heat, chemicals, and desiccation, making them difficult to destroy.

Question 10

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

Accepted Answer

It is an irregularly shaped region containing the bacterial chromosome, not surrounded by a membrane.

Question 11

Which of the following is a correct statement about the coordination of DNA replication and cell division in prokaryotes?

Accepted Answer

DNA replication and cell division are tightly coupled, allowing rapid population growth.

Question 12

Which of the following best explains the difference between isotonic, hypotonic, and hypertonic solutions for prokaryotic cells?

Accepted Answer

In a hypotonic solution, water enters the cell; in a hypertonic solution, water leaves the cell; in an isotonic solution, there is no net water movement.

Question 13

Which of the following is a plausible reason why Gram-negative bacteria are generally more resistant to detergents than Gram-positive bacteria?

Accepted Answer

The outer membrane of Gram-negative bacteria acts as a barrier to many detergents.

Question 14

Which of the following best describes the function of bacterial storage granules?

Accepted Answer

They store nutrients such as glycogen or polyphosphate for later use.

Question 15

Which of the following is a medically important endospore-forming bacterium that can cause disease in humans?

Accepted Answer

Clostridium botulinum

Question 16

A scientist stains a bacterial sample and observes purple cells under the microscope. Which of the following is the most likely explanation?

Accepted Answer

The bacteria are Gram-positive, retaining the crystal violet stain due to a thick peptidoglycan layer.

Question 17

Which of the following best explains how pili contribute to bacterial survival?

Accepted Answer

They facilitate attachment to surfaces and other cells, aiding colonization and gene transfer.

Question 18

Which of the following is a correct statement about the structure of a typical prokaryotic cell?

Accepted Answer

It contains a nucleoid region, ribosomes, plasma membrane, cell wall, and sometimes flagella or pili.

Question 19

Which of the following best explains why antibiotics that target bacterial ribosomes are generally not toxic to human cells?

Accepted Answer

Bacterial ribosomes (70S) differ structurally from eukaryotic ribosomes (80S), allowing selective targeting.

Prokaryotic Cell Structure and Function: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard