Final answer:
Oral streptococci strains are predominantly alpha-hemolytic, where they alter hemoglobin to methemoglobin, which appears greenish around the bacterial colonies on Blood Agar Plates.
Step-by-step explanation:
Oral streptococci strains are predominantly C. alpha-hemolytic. This classification is based on the type of hemolysis observed when these bacteria are grown on Blood Agar Plates. Alpha-hemolysis, also known as green or partial hemolysis, is characterized by the reduction of hemoglobin in red blood cells to methemoglobin, giving a greenish color around the colonies. It is distinct from beta-hemolysis, which completely lyses red blood cells, and gamma hemolysis, also known as non-hemolytic, where no hemolysis occurs. Oral streptococci, such as Streptococcus mutans, a contributor to dental caries, generally do not cause complete lysis of red blood cells but may alter the hemoglobin to a reduced form that imparts a greenish hue surrounding the bacterial colonies.