Question 1

Which organism is responsible for causing tuberculosis, and what is its classification?

Accepted Answer

Mycobacterium tuberculosis; acid-fast bacillus

Question 2

A patient presents with ringworm. Which organism is most likely responsible, and what is its classification?

Accepted Answer

Trichophyton rubrum; fungus

Question 3

Which of the following pathogens is transmitted by the vector shown in $$image_10$$ and is responsible for Lyme disease?

Accepted Answer

Ixodes spp.

Question 4

A blood smear shows ring forms inside red blood cells. Which protozoan is most likely present, and what disease does it cause?

Accepted Answer

Plasmodium spp.; malaria

Question 5

Which organism is identified by its acid-fast staining properties and clumped bacilli appearance under the microscope?

Accepted Answer

Mycobacterium tuberculosis

Question 6

A patient with a tapeworm infection is found to have eggs with a radiating shell pattern. Which organism is responsible?

Accepted Answer

Taenia solium

Question 7

Which organism is a nematode helminth and is identified by its pale ring, darker center, and bumpy surface eggs?

Accepted Answer

Ascaris lumbricoides

Question 8

A patient presents with scabies. Which organism is responsible, and where are its eggs typically found?

Accepted Answer

Sarcoptes scabiei var. hominis; under the surface of the skin

Question 9

Which organism is a yeast fungus and can appear as either yeast or hyphae under the microscope?

Accepted Answer

Candida albicans

Question 10

Which protozoan is teardrop-shaped and causes giardiasis?

Accepted Answer

Giardia spp.

Question 11

A patient is diagnosed with Chagas disease. Which protozoan is responsible, and what is its appearance in blood smears?

Accepted Answer

Trypanosoma spp.; worm-like in red blood cells

Question 12

Which vector is responsible for transmitting malaria, and what is its classification?

Accepted Answer

Anopheles spp.; mosquito (animal, biological vector)

Question 13

Which organism is classified as a trematode helminth and is identified by an egg with a spine resembling a speech bubble?

Accepted Answer

Schistosoma mansoni

Question 14

Which dsDNA virus is associated with melting red blood cells and causes mononucleosis?

Accepted Answer

Epstein-Barr virus

Question 15

A Gram stain of bacteria shows dark purple, blue-stained clusters. Which organism is most likely present?

Accepted Answer

Staphylococcus aureus

Question 16

Which protozoan is flagellated and causes trichomoniasis?

Accepted Answer

Trichomonas vaginalis

Question 17

A patient presents with valley fever. Which organism is responsible, and what is its classification?

Accepted Answer

Coccidioides immitis; fungus

Question 18

Which organism is responsible for causing ascariasis, and what is its classification?

Accepted Answer

Ascaris lumbricoides; nematode helminth

Question 19

Which organism is responsible for causing taeniasis, and what is its classification?

Accepted Answer

Taenia solium; cestode helminth

Question 20

A patient presents with candidiasis. Which organism is responsible, and what is its classification?

Accepted Answer

Candida albicans; yeast fungus

Key Microbial Pathogens and Their Microscopic Identification

Study Guide - Practice Questions