Q.83 Based on their properties, match the “Genera” in Group 1 with those in Group 2
Group 1
P. Bacillus
Q. Neisseria
R. Rhizobium
S. Caulobacter
Group 2
1. Sarcina
2. Azotobacter
3. Hyphomicrobium
4. Clostridium
(A) P-4, Q-1, R-2, S-3
(B) P-4, Q-1, R-3, S-2
(C) P-2, Q-4, R-1, S-3
(D) P-1, Q-4, R-2, S-3
Bacillus Neisseria Rhizobium Caulobacter Genera Properties Matching
Bacillus shares endospore-forming rod properties with Clostridium, while Neisseria matches diplococci resembling Sarcina arrangements. Rhizobium and Caulobacter link to free-living and stalked nitrogen-fixers like Azotobacter and Hyphomicrobium, respectively. The correct answer is option (A).
Correct Answer
(A) P-4, Q-1, R-2, S-3
This matching groups genera by shared morphological, physiological, or ecological properties in bacterial taxonomy.
Genera Properties
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P. Bacillus → 4. Clostridium: Both Gram-positive, rod-shaped (bacilli), aerobic/facultative vs strict anaerobes, form heat-resistant endospores.
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Q. Neisseria → 1. Sarcina: Both cocci; Neisseria diplococci (pairs), Sarcina tetrads/packets from division in two/three planes, Gram-negative vs positive.
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R. Rhizobium → 2. Azotobacter: Both nitrogen-fixing; Rhizobium symbiotic rods in legume nodules, Azotobacter free-living aerobic cysts/polysaccharides.
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S. Caulobacter → 3. Hyphomicrobium: Both prosthecate; stalked cells for adhesion, asymmetric division, aquatic oligotrophs.
Option Analysis
| Option | Matching | Why Correct/Incorrect |
|---|---|---|
| (A) | P-4, Q-1, R-2, S-3 | Correct: Endospores (Bacillus-Clostridium), cocci forms (Neisseria-Sarcina), N-fixers (Rhizobium-Azotobacter), prosthecate (Caulobacter-Hyphomicrobium). |
| (B) | P-4, Q-1, R-3, S-2 | Wrong: Rhizobium not prosthecate like Hyphomicrobium (3); Caulobacter not free-living N-fixer like Azotobacter (2). |
| (C) | P-2, Q-4, R-1, S-3 | Wrong: Bacillus not N-fixer Azotobacter (2); Neisseria cocci not rods Clostridium (4). |
| (D) | P-1, Q-4, R-2, S-3 | Wrong: Bacillus rods not cocci Sarcina (1); Neisseria not anaerobes Clostridium (4). |
Introduction to Bacterial Genera Matching
Matching Bacillus, Neisseria, Rhizobium, Caulobacter genera properties evaluates bacterial morphology like endospores, cocci arrangements, nitrogen-fixation, and prosthecae in microbiology taxonomy. This MCQ highlights similarities with Clostridium, Sarcina, Azotobacter, Hyphomicrobium for exams like CSIR NET biotech.
Shared Properties Explained
Bacillus and Clostridium both form endospores as Gram-positive rods, surviving extremes. Neisseria diplococci pair like Sarcina’s packet-forming cocci via orthogonal division. Rhizobium fixes N2 symbiotically, akin to free-living Azotobacter’s cysts. Caulobacter’s stalks mirror Hyphomicrobium’s hyphae/prosthecae for budding reproduction.
Why Option A Wins for Microbiology Students
Option A correctly groups by properties: spore-formers, cocci, N-fixers, stalked bacteria—essential for understanding phylogeny and ecology in advanced microbio courses.
