Stain is not taken by capsule in gram negative organisms because the capsule consist of -
a) Polysaccharides
b) Lipopolysaccharides
c) Lipids
d) Protein
1.b
2.c
3.ac
4.ad
Explanation:
- Capsules are protective walls that surround the cell membranes of gram-positive and gram-negative bacteria.
- They are usually composed of simple sugar (polysaccharide) except in Bacillus anthracis it is made up of polypeptide (protein).
- Capsule is not visible in gram stained smear as it has little affinity for basic dyes.
Note -
- For single option go ahead for option ‘a’, i.e. polysaccharide because, except for Bacillus anthracis, the capsule of almost all the important bacteria is composed of sugar (polysaccharide).
- Don’t get confuse with word gram-negative in question because the capsule, whether it is of grain positive or gram negative bacteria, is not visible on gram staining.