You are given an electron micrograph of a bacterial cell. In the micrograph you can clearly see three thin layers of different densities surrounding the cell. Based on the micrograph, you can infer that this cell is ________ and would appear ________ after application of the Gram stain procedure.
A) gram-positive / purple
B) gram-negative / pink
C) gram-positive / pink
D) gram-negative / purple

Question

Quizplus · Accepted Answer

The presence of three thin layers of different densities surrounding the cell indicates that it is a gram-negative bacterium. The Gram stain procedure involves applying crystal violet, iodine, alcohol, and safranin to the bacterial cells, which allows gram-positive cells to retain the violet color and appear purple under the microscope, while gram-negative cells lose the violet color and appear pink after the addition of safranin.

You Are Given an Electron Micrograph of a Bacterial Cell