1
Why is a capsule advantageous to a bacterium?
- It protects the bacterium from desiccation.
- It provides means of locomotion
- It allows bacterium to "hide" from host's immune system.
- It allows the bacterium to attach to the surface.
Answer
(3) It allows bacterium to "hide" from host's immune system.
Solution
As per NCERT, the glycocalyx of a bacterium may be a loose sheath (slime layer) or thick and tough (capsule).
⇒ The thick polysaccharide capsule masks the surface antigens of the bacterium and resists phagocytosis by white blood cells.
∴ A capsule allows a pathogenic bacterium to "hide" from the host's immune system, which makes it more virulent.
∵ Locomotion is due to flagella and attachment to surfaces is mainly by pili and fimbriae, options (2) and (4) are not the main advantage of a capsule.
Answer: (3)
NEET 2013 (Karnataka)