Which of the following best describes the cellular arrangement of streptococci?

• A. They form pairs of spiral-shaped cells.
• B. They form clusters of rod-shaped cells.
• C. They form tetrads of cuboidal cells.
• D. They form chains of spherical cells.

Answer: (D)

Verified step by step guidance

1. Understand the morphology and arrangement terms used to describe bacteria: 'cocci' refers to spherical-shaped cells, 'bacilli' to rod-shaped cells, and 'spirilla' to spiral-shaped cells.
2. Recall that 'strepto-' is a prefix used to describe bacteria that form chains, while 'staphylo-' describes bacteria that form clusters.
3. Identify that streptococci are spherical (cocci) bacteria that characteristically arrange themselves in chains.
4. Compare the options given: pairs of spiral-shaped cells would describe diplospirilla, clusters of rod-shaped cells would describe staphylobacilli (which is uncommon), tetrads of cuboidal cells describe sarcina, and chains of spherical cells describe streptococci.
5. Conclude that the best description of streptococci is 'They form chains of spherical cells' based on their morphology and arrangement.