Streptococcus has a generally round shape and it is studied in biology.
==== The viridans group: alpha-hemolytic ====The viridans streptococci are a large group of commensal bacteria that are either alpha-hemolytic, producing a green coloration on blood agar plates (hence the name "viridans", from Latin vrdis, green), or nonhemolytic
Beta-hemolytic streptococci are further classified by Lancefield grouping, a serotype classification (that is, describing specific carbohydrates present on the bacterial cell wall)

