Pathogens and disease Knowledge-Based Practice

Questions

1. 1.

   Which of the following molecules serves as the primary bacterial endotoxin embedded in the outer membrane of Gram-negative pathogens and is typically released upon cell lysis to trigger an intense immune reaction?

   • A) Peptidoglycan composing the bacterial cell wall
   • B) Lipopolysaccharide anchored in the outer membrane
   • C) Teichoic acid spanning the Gram-positive cell envelope
   • D) Pilin protein forming surface attachment structures
2. 2.

   Which of the following types of pathogens is an acellular agent composed entirely of an abnormally folded protein and completely lacks a nucleic acid genome?

   • A) Viroid
   • B) Bacteriophage
   • C) Mycoplasma
   • D) Prion
3. 3.

   Which of the following cellular features is present in pathogenic fungi, but absent in both pathogenic bacteria and viruses, and serves as a specific target for antifungal agents?

   • A) Peptidoglycan in the cell wall
   • B) A protein capsid surrounding nucleic acid
   • C) 70S ribosomes in the cytoplasm
   • D) Chitin within the cell wall
4. 4.

   Which of the following infectious diseases is caused by a eukaryotic protozoan pathogen that is transmitted to humans through an insect vector?

   • A) Tuberculosis
   • B) Malaria
   • C) Cholera
   • D) Measles
5. 5.

   Which of the following statements correctly distinguishes pathogenic viruses from pathogenic bacteria in terms of how they interact with and harm a host organism?

   • A) Pathogenic viruses produce metabolic exotoxins that damage cell membranes, whereas pathogenic bacteria must integrate into the host genome to cause illness.
   • B) Pathogenic viruses must replicate inside living host cells and typically destroy them upon release, whereas pathogenic bacteria can replicate independently and often cause damage through the secretion of toxins.
   • C) Pathogenic viruses possess a rigid peptidoglycan wall that provokes inflammatory responses, whereas pathogenic bacteria lack any cell boundary and rely entirely on host enzymes.
   • D) Pathogenic viruses actively consume host nutrients through extracellular digestion, whereas pathogenic bacteria are obligate intracellular agents incapable of extracellular survival.

Answers and step-by-step solutions appear after you finish the test.