Streptococcus belongs to an order that is coccus-shaped and it is studied in biology.
Biology is a natural science concerned with the study of life and living organisms , including their structure , function , growth , evolution , distribution , identification and taxonomy . Sub-disciplines of biology are defined by the scale at which organisms are studied , the kinds of organisms studied , and the methods used to study them : biochemistry examines the rudimentary chemistry of life ; molecular biology studies the complex interactions among biological molecules ; botany studies the biology of plants ; cellular biology examines the basic building-block of all life , the cell ; physiology examines the physical and chemical functions of tissues , organs , and organ systems of an organism ; evolutionary biology examines the processes that produced the diversity of life ; and ecology examines how organisms interact in their environment . Lactobacillales or lactic acid bacteria ( LAB ) are an order of Gram-positive , low-GC , acid-tolerant , generally nonsporulating , nonrespiring , either rod - or coccus-shaped bacteria that share common metabolic and physiological characteristics . Streptococcus is a genus of coccus ( spherical ) Gram-positive bacteria belonging to the phylum Firmicutes and the order Lactobacillales ( lactic acid bacteria ) .