Q.82 Match organisms in Group I with shapes in Group II and flagellar arrangements in Group III.
| Group I |
|---|
| (P) Salmonella typhi (Q) Saccharomyces cerevisiae (R) Aquaspirillum serpens (S) Vibrio cholerae |
| Group II |
|---|
| (i) helical (ii) rod (iii) curved rod (iv) ovoid |
| Group III |
|---|
| (1) non-motile (2) amphitrichous (3) peritrichous (4) polar |
Introduction
Microorganisms exhibit distinct cellular shapes and flagellar arrangements, which are key diagnostic features in microbiology. These characteristics help in identification, classification, and understanding motility patterns of microbes.
Exam questions often test the ability to simultaneously correlate:
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the organism,
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its cell shape, and
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its flagellar arrangement.
This article explains the correct matching of organisms given in the question and evaluates all answer options.
Correct Matching with Explanation
P. Salmonella typhi
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Shape: Rod (ii)
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Flagella: Peritrichous (3)
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Explanation:
Salmonella species are rod-shaped bacteria with flagella distributed all over the surface, enabling strong motility.
Q. Saccharomyces cerevisiae
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Shape: Ovoid (iv)
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Flagella: Non-motile (1)
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Explanation:
Yeast cells are oval or ovoid in shape and lack flagella, hence are non-motile.
R. Aquaspirillum serpens
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Shape: Helical (i)
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Flagella: Amphitrichous (2)
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Explanation:
Aquaspirillum is a spiral/helical bacterium with flagella at both ends, a classic example of amphitrichous arrangement.
S. Vibrio cholerae
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Shape: Curved rod (iii)
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Flagella: Polar (4)
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Explanation:
Vibrio cholerae has a comma-shaped (curved rod) morphology and a single polar flagellum.
Correct Answer
✅ Option (A)
P-ii-3, Q-iv-1, R-i-2, S-iii-4
Option-Wise Analysis
Option (A)
✅ Correct
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All organisms are accurately matched with their correct shape and flagellar arrangement.
Option (B)
❌ Incorrect
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Saccharomyces cerevisiae is not helical.
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Vibrio cholerae is not peritrichous.
Option (C)
❌ Incorrect
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Salmonella typhi is not amphitrichous.
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Vibrio cholerae is not peritrichous.
Option (D)
❌ Incorrect
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Saccharomyces cerevisiae is not rod-shaped.
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Aquaspirillum does not show peritrichous flagella.
Quick Revision Table
| Organism | Shape | Flagella |
|---|---|---|
| Salmonella typhi | Rod | Peritrichous |
| Saccharomyces cerevisiae | Ovoid | Non-motile |
| Aquaspirillum serpens | Helical | Amphitrichous |
| Vibrio cholerae | Curved rod | Polar |
Conclusion
Accurate identification of microorganisms requires a clear understanding of cell morphology and flagellar distribution. These traits are stable, characteristic, and highly testable in exams.
Among the given options, Option (A) correctly matches all organisms with their respective shapes and flagellar arrangements.
Final Answer
✅ Option (A): P-ii-3, Q-iv-1, R-i-2, S-iii-4
