What term refers to spherical-shaped bacteria that grow in pairs and can cause pneumonia?

The term that specifically refers to spherical-shaped bacteria that grow in pairs and can cause pneumonia is "diplococci." This classification is derived from the Greek words "diplos," meaning double, and "coccus," meaning berry, which describes their characteristic arrangement. Diplococci are involved in various infections, with certain types, such as Neisseria pneumoniae, being significant pathogens responsible for pneumonia in humans.

In contrast, the general term "cocci" refers to spherical bacteria but does not specify their arrangement. This makes it a broader classification that includes not just pairs but also single, chains, or clusters of spherical bacteria.

"Bacilli" are rod-shaped bacteria, while "spirilla" describes bacteria that have a spiral shape. Since neither of these shapes corresponds to the description of spherical bacteria, they do not apply to the specific scenario of bacteria that grow in pairs and are associated with pneumonia. Thus, the most accurate and specific term for this type of bacteria is "diplococci."