A clinical microbiologist isolates a strain of the bacterium Klebsiella pneumoniae. Under an electron microscope, the cells are observed to have a thick, gelatinous outer layer surrounding their murein cell wall, which protects them from engulfment by host white blood cells. Additionally, these bacteria are observed to be non-motile.
Which of the following correctly pairs the cellular structure that protects K. pneumoniae from phagocytosis with the structure whose absence explains its lack of motility?
Protective structure: capsule; Absent structure: flagella
Protective structure: murein cell wall; Absent structure: flagella
Protective structure: capsule; Absent structure: plasmids
Protective structure: capsule; Absent structure: pili
