Increased in turbidity is an index of bacterial growth The p

Increased in turbidity is an index of bacterial growth. The primary stain of the gram\'s staining reaction is called methylene blue. The secondary/counter stain of the gram\'s staining reaction is crystal violet: iodine Gram positive cells have a thin layer cell peptidoglycan. Crystal violet is used in staining acid fast organisms. Colony consists of a group genetically identical cells of bacterium. Streak-plate technique yields quantitative information. Thioglycollate medium is used to identify gram negative organisms Turbidometeric methods are used to count live cells. MSA plates selects for halophiles. Simple staining method uses simple stains. A Simple stain will show the capsule and the flagellum of bacteria cell.

Solution

Question no. 31.

i). False.

Reason: Growth of bacteria in culture medium makes the media turbid. More the turbidity more is the bacterial growth.

ii) False.

Reason: The bacteria are stained with Gram stain to investigate the Gram character of the bacteria. The bacteria are first stained with Crystal Violet. Gram-negative bacteria can not take crystal violet stain due to the thin cell walls. The cells were then counter-stained with pink safranin.

iii). False.

Reason: Secondary stain is Safranin and not Iodine. Iodine may be added to primary stain to prolong its binding to the cell wall of Gram-positive bacteria.

iv). False

Reason: Gram-positive bacteria have thicker cell walls due to higher peptidoglycan and lipid content as compared with the Gram-negative ones.

v). False

Reason: Acid-fast cells do not take crystal-violet stain due to the presence of the waxy lipid in their cell wall.

vi).True

vii). False

Streak plate technique is to isolate a single pure colony. It is a qualitative technique.

x) False

Thioglycolate is to determine the oxygen requirement

Viii). False

Turbidometric test would measure all bacteria, whether living or dead

ix). True

x) True

xi) False

Capsule and flagella needs special staining