Question 1

Which of the following statements best describes the difference between the cell walls of Bacteria and Archaea?

Accepted Answer

Bacterial cell walls are primarily composed of peptidoglycan, while archaeal cell walls lack peptidoglycan and may contain pseudopeptidoglycan.

Question 2

A microbiologist observes a bacterium that can change its shape in response to environmental conditions. What is the term for this property, and what is its main advantage?

Accepted Answer

Pleomorphism; it allows the bacterium to adapt to different environments and evade immune responses.

Question 3

Which of the following best explains why Gram-negative bacteria are less susceptible to penicillin than Gram-positive bacteria?

Accepted Answer

Gram-negative bacteria have an outer membrane that acts as a barrier to penicillin, limiting its access to the thin peptidoglycan layer.

Question 4

A patient is diagnosed with a lung infection caused by Mycobacterium tuberculosis. Which staining property and cell wall component are most relevant for laboratory identification?

Accepted Answer

Acid-fast staining; mycolic acid in the cell wall.

Question 5

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

Accepted Answer

They provide motility, allowing bacteria to move toward or away from stimuli such as chemicals (chemotaxis) or light (phototaxis).

Question 6

Which of the following is the main molecule found in the nucleoid region of a prokaryotic cell?

Accepted Answer

DNA

Question 7

A bacterial cell is placed in a solution with a higher solute concentration than the cytoplasm. Which process will occur, and what is the name for this type of solution?

Accepted Answer

Water will move out of the cell by osmosis; the solution is hypertonic.

Question 8

Which of the following best describes the difference between simple diffusion and facilitated diffusion across a prokaryotic plasma membrane?

Accepted Answer

Simple diffusion does not require membrane proteins, while facilitated diffusion requires specific transport proteins.

Question 9

Which of the following genera is best known for lacking a cell wall and being resistant to antibiotics that target peptidoglycan synthesis?

Accepted Answer

Mycoplasma

Question 10

A scientist is studying a prokaryotic cell that contains a 70S ribosome. Which of the following statements is correct regarding this ribosome?

Accepted Answer

It is smaller than the 80S ribosome found in eukaryotic cells.

Question 11

Which of the following is a function of bacterial capsules that increases their pathogenicity?

Accepted Answer

They help bacteria evade phagocytosis and promote adhesion to host tissues.

Question 12

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

Accepted Answer

It is an asexual process in which a single cell divides to produce two genetically identical daughter cells.

Question 13

Which of the following is the core component of the outer membrane of Gram-negative bacteria that acts as an endotoxin?

Accepted Answer

Lipid A portion of lipopolysaccharide (LPS)

Question 14

Which of the following best explains why mitochondria and chloroplasts are considered evidence for the endosymbiotic theory?

Accepted Answer

They contain 70S ribosomes, similar to prokaryotes.

Question 15

A bacterium is found to have fimbriae and pili. What is the primary function of these structures?

Accepted Answer

Attachment to surfaces and other cells, and in some cases, transfer of genetic material.

Question 16

Which of the following best describes the function of inclusion bodies in prokaryotic cells?

Accepted Answer

They store nutrients and other substances for later use.

Question 17

Which of the following genera are the best-known examples of acid-fast bacteria?

Accepted Answer

Mycobacterium and Nocardia

Question 18

Which of the following is a medically relevant genus that produces endospores?

Accepted Answer

Clostridium

Question 19

Which of the following best describes the difference between active and passive transport across the prokaryotic plasma membrane?

Accepted Answer

Active transport requires energy (usually ATP) to move substances against their concentration gradient, while passive transport does not require energy and moves substances down their concentration gradient.

Question 20

A patient is infected with an enteric bacterium. Where in the body is this bacterium most likely to be found?

Accepted Answer

In the intestines

Study Guide: Introduction to Prokaryotic Cells (Microbiology)

Guida di studio - Domande di pratica

Study guide - Flashcard