Q.11 Bacteria containing a tuft of flagella that comes out from one pole is called ___.
(A) Lophotrichous
(B) Peritrichous
(C) Monotrichous
(D) Amphitrichous
The correct answer is (A) Lophotrichous. Bacteria with a tuft of flagella emerging from one pole feature multiple flagella bundled at a single end, enabling coordinated propulsion. This arrangement matches the description precisely among the options.
Option Explanations
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(A) Lophotrichous: Multiple flagella form a tuft at one pole, acting together for directed movement, as in Pseudomonas fluorescens or Spirillum volutans.
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(B) Peritrichous: Flagella distribute across the entire cell surface, excluding poles, allowing bundle formation during swimming, seen in E. coli or Salmonella.
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(C) Monotrichous: A single flagellum attaches at one pole for propulsion, typical in Vibrio cholerae.
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(D) Amphitrichous: Single flagella (or rarely tufts) appear at both poles, as in Alkaligenes faecalis.
Bacteria tuft flagella one pole lophotrichous arrangement defines microbes like Pseudomonas with bundled polar flagella for swift navigation in viscous environments.
Flagella Structure Basics
Flagella consist of flagellin protein filaments, basal body motors, and hooks, rotating via proton motive force for bacterial motility. Gram-negative types feature L, P, and MS rings; Gram-positive have fewer.
Arrangement Types Compared
| Type | Flagella Description | Pole Location | Examples |
|---|---|---|---|
| Lophotrichous | Tuft (multiple) at one pole | Single end | Pseudomonas fluorescens, Spirillum volutans |
| Peritrichous | Multiple over entire surface | All around | E. coli, Salmonella |
| Monotrichous | Single flagellum | One pole | Vibrio cholerae |
| Amphitrichous | Single (or tufts) at both poles | Both ends | Alkaligenes faecalis |
Lophotrichous tufts bundle at polar organelles for energy-efficient thrust.
CSIR NET Relevance
This topic falls under Unit 1 (Microbiology), testing flagellar arrangements for identification and motility mechanisms vital for exams. Examples like Campylobacter jejuni highlight pathogenic roles.
