MMBIO 222: Quiz 2 with Complete Solutions

Simple stain Correct Answer-Staining bacteria with a single dye. Does not differentiate. Shows morphology and arrangement. Two results of heat fixation Correct Answer-1. Kills the bacteria 2. Attaches it to the slide What is a dye? Correct Answer-A salt of a chromophore group and an oppositely charged ion. Most often it is a basic dye. Examples of dyes Correct Answer-Crystal violet, safranin, methylene blue, and carbolfuchsin What is a capsule? Correct Answer-A gelatinous covering around the outside of a cell. Composed of polysaccharides. Benefits (to the bacteria) of a capsule Correct Answer-1. Interfere with phagocytosis 2. Promote infection by attaching readily 3. Resistant to lethal action of complement 4. Resistant to lethal action of metals, dehydrating, and attack by bacterial viruses Quellung test Correct Answer-Capsular swelling in the presence of a specific antibody. Can identify specific