HOSA Microbiology Practice Test 2025 Questions and Answers

Viruses are the smallest known infectious agents. Although they are not considered "living" by all definitions, they are smaller than bacteria, chlamydia, and rickettsia.

Rocky Mountain spotted fever is transmitted by tick bites, particularly from the Dermacentor species, and is characterized by a distinctive rash and systemic symptoms.

Yeasts are unicellular eukaryotic fungi that can synthesize proteins and vitamins, making them useful in food production and as nutritional supplements.

The correct spelling is “mycobacteria” (without the extra “e”).

Malaria is transmitted by the bite of an infected female Anopheles mosquito, which serves as the vector for the Plasmodium parasites.

coli is a common cause of urinary tract infections. It is also associated with gastrointestinal infections but is not responsible for gonorrhea, which is caused by Neisseria gonorrhoeae.

Bacillary dysentery is caused by Shigella species, making the condition also known as shigellosis.

Neisseria gonorrhoeae is a diplococcus (spherical and arranged in pairs), not rod shaped like the others listed.

Chlamydial infections often produce mucopurulent cervicitis or urethritis. While gonorrhea can also produce purulent discharge, the term “mucopurulent” is classically associated with chlamydia.

A virus that infects bacteria is specifically called a bacteriophage. The other terms relate to the inhibition or killing of bacteria by drugs.

Streptococci typically arrange themselves in chains, while staphylococci are found in clusters.

Molds (multicellular filamentous fungi) are the primary source of many antibiotics, such as penicillin from Penicillium species.

The correct spelling is “legionellosis” (without the extra “j”).

Autotrophs synthesize their own organic compounds from inorganic carbon dioxide, using light (photoautotrophs) or chemical reactions (chemoautotrophs) as an energy source.

Streptococci characteristically arrange themselves in chains, while staphylococci form clusters.

Species in the genus Clostridium produce some of the most potent exotoxins known (e.g., tetanus toxin, botulinum toxin).

Symbiosis refers to any close, long-term biological interaction between two different organisms, which can be mutualistic, commensalistic, or parasitic.

Staphylococci are characterized by their arrangement in clusters that resemble bunches of grapes. In contrast, streptococci form chains, spirochetes are spiral shaped, and the others have different morphologies.

Epstein-Barr virus (EBV) is the primary cause of infectious mononucleosis, also known as “mono” or the “kissing disease.”

Virulence refers to the degree of pathogenicity or the “power” of a microorganism to cause disease. Although pathogenicity also relates to disease-causing ability, virulence specifically denotes the intensity or severity of that ability.

The Gram stain does not work for all bacteria. Some bacteria (e.g., those lacking a typical cell wall structure, such as Mycoplasma) do not retain the Gram stain.

Spirilla are spiral-shaped bacteria. Cocci are spherical, bacilli are rod-shaped, and diplococci are spherical bacteria arranged in pairs.

Rickettsia are obligate intracellular bacteria that require a vector (such as ticks, lice, or fleas) for transmission. The other listed organisms do not depend on vectors for their spread.

Rabies often presents with fever, headache, and neurological symptoms (confusion, agitation, and altered sleep patterns) following an animal bite. Although hydrophobia is a hallmark, the overall neurological deterioration is key to suspecting rabies.