Viruses are classified by all of the following characteristics, except

A. Primary and secondary: Primary and secondary are general terms for stages or classifications but are not the accepted categories used to describe fungi that cause human disease.

B. Primary and vegetative: Vegetative refers to the active, growing form of a fungus (hyphae or yeast), which is a morphological description, not a category of pathogenicity.

C. Opportunistic and primary: Primary fungi can cause disease in healthy hosts, while opportunistic fungi cause disease mainly in immunocompromised individuals. These two categories encompass the major ways fungi lead to human illness.

D. Secondary and opportunistic: Opportunistic fungi are correct, but secondary is not used as a distinct category for fungal pathogens.

E. Vegetative and reproductive: Vegetative and reproductive describe fungal growth forms or structures, not their disease-causing categories in humans.

A. It has sterols (like cholesterol) in its membrane: Sterols insert themselves between phospholipids in the cell membrane, preventing tight packing of fatty acid chains. This helps maintain fluidity even in cold environments, allowing essential processes like transport and signaling to continue.

B. It has a higher amount of protein in its membrane: While membrane proteins are crucial for transport and enzymatic functions, they do not significantly impact the bilayer’s ability to remain fluid in near-freezing temperatures.

C. It has a thicker glycocalyx: The glycocalyx primarily aids in protection, adhesion, and biofilm formation. It does not play a major role in maintaining membrane fluidity under cold stress.

D. It has a thick cell wall: A thick cell wall protects against osmotic lysis and provides shape, but it does not regulate the lipid bilayer’s flexibility or prevent rigidity in freezing conditions.