Final answer:
The term 'bacillus' usually refers to a rod-shaped bacterium, but in taxonomy, the class Bacilli can include both bacillus-shaped and coccus-shaped bacteria such as Bacillus and Staphylococcus.
Step-by-step explanation:
The word 'bacillus' refers to bacteria that are rod-shaped. However, in a broader taxonomic sense, the class Bacilli is not just limited to rod-shaped bacteria but includes both bacillus-shaped and coccus-shaped genera. It includes various species, with some of the clinically significant ones being Bacillus and Staphylococcus. Bacillus is a genus of bacteria that are indeed bacillus in shape and can produce endospores. These bacteria may be aerobic or facultative anaerobes and have applications in industries such as antibiotics, enzymes, and detergents production. On the other hand, although Staphylococcus is included in the class Bacilli, it is coccus-shaped, resembling bunches of grapes in culture. This class of bacteria is diverse and is sorted based on various characteristics including their Gram stain reaction, shape, and other cellular and metabolic features.