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.

1. 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

2. ix). True
x) True
xi) False
Capsule and flagella needs special staining