Wisconsin Esthetics State Board Practice Test

Which bacterial structure is characterized by growing in pairs and often leads to pneumonia?

1. Bacilli

2. Streptococci

3. Diplococci

4. Spirilla

The correct answer is: Diplococci

The bacterial structure characterized by growing in pairs is known as diplococci. This type of bacteria has a unique arrangement where two spherical bacteria are joined together, resulting in a cocci shape that can often be seen under a microscope. Diplomococci are particularly significant in medical microbiology because certain species, such as Streptococcus pneumoniae, are known to cause pneumonia and other respiratory infections. In contrast, bacilli refers to rod-shaped bacteria, which do not typically grow in pairs, and spirilla are spiral-shaped bacteria. Streptococci usually grow in chains rather than pairs. Understanding these differences helps in identifying bacterial pathogens and their potential impact on human health, particularly concerning respiratory illnesses.