Question

How many basal body rings do Gram positive bacteria have in the flagella?

(a) 2

(b) 3

(c) 4

(d) 1

This question was posed to me in a job interview.

This intriguing question originated from Two Fundamentally Different Classes of Cells in chapter Introduction to Cell of Cell Biology

Answer 1

Correct choice is (a) 2

For explanation: Gram positive bacteria have 2 basal rings in the flagella, one in the peptidoglycan layer and one in the plasma membrane. Gram negative bacteria have 4 basal rings in their flagella. The L ring is located in the plane in the outer membrane, P ring in the plane of peptidoglycan around flagellar rod, MS ring that is located within and above cytoplasmic membrane and C ring extends into the cytoplasm.