AP-Micro Bacterial Classification 3

Question 1

Which of the following cell arrangements describes bacteria that divide in one plane and remain attached in chains?

Accepted Answer

Streptococci

Answer

Streptococci divide in a single plane and remain attached, forming chains of spherical cells.

Question 2

Proteobacteria are subdivided into classes (Alpha, Beta, Gamma, etc.) based on:

Accepted Answer

16S rRNA sequence similarity

Answer

Classes within Proteobacteria are defined by 16S rRNA phylogenetic analysis reflecting evolutionary relatedness.

Question 3

Which genus forms endospores that allow survival in boiling water for extended periods?

Accepted Answer

Clostridium

Answer

Clostridium (and Bacillus) endospores are highly heat-resistant structures that can survive boiling temperatures.

Question 4

A Gram-negative diplococcus isolated from a urethral swab is most likely which organism?

Accepted Answer

Neisseria gonorrhoeae

Answer

Neisseria gonorrhoeae is a Gram-negative diplococcus and the causative agent of gonorrhea.

Question 5

What is the primary basis for distinguishing Streptococcus species from one another in clinical labs?

Accepted Answer

Hemolysis pattern on blood agar

Answer

Streptococci are categorized as alpha-, beta-, or gamma-hemolytic based on how they lyse red blood cells on blood agar.

AP Practice Test