Q.77 Match the correct mode of cell division with respective bacteria.
Bacteria
(P) Streptomyces species
(Q) Rhodopseudomonas acidophila
(R) Bacillus subtilis
(S) Nocardia species

(A) (P)-(ii), (Q)-(iii), (R)-(i), (S)-(iv)
(B) (P)-(ii), (Q)-(i), (R)-(iii), (S)-(iv)
(C) (P)-(iv), (Q)-(ii), (R)-(i), (S)-(iii)
(D) (P)-(i), (Q)-(iv), (R)-(iii), (S)-(ii)

Matching Bacterial Species to Cell Division Modes: Streptomyces, Rhodopseudomonas, Bacillus subtilis, and Nocardia

Binary fission represents the standard mode of asexual reproduction in most bacteria, but species like Streptomyces species, Rhodopseudomonas acidophila, Bacillus subtilis, and Nocardia species exhibit specific variations tailored to their lifestyles.

Question Breakdown

The query requires matching four bacterial species to illustrated modes of cell division, labeled (i) through (iv), with options (A) through (D) providing combinations such as (P)-(i), (Q)-(ii), etc. Diagrams typically depict: (i) binary fission (midcell constriction), (ii) budding (outgrowth from pole), (iii) fragmentation (hyphal breaking), and (iv) septation (multiple cross-walls or sporulation ladders). Correct matching aligns with biological traits: (C) (P)-(v), (Q)-(ii), (R)-(i), (S)-(iii), assuming (v) denotes sporulation septa or cross-walls for Streptomyces, though standard labels adjust to fragmentation/septation for filamentous forms.

Species Explanations

Streptomyces species (P): Filamentous actinomycetes form multinucleate hyphae with infrequent vegetative cross-walls, fragmenting into spores during sporulation via multiple synchronous septa, distinct from rod binary fission. Matches diagram (iii) or (iv) showing hyphal septation/fragmentation.

Rhodopseudomonas acidophila (Q): This photosynthetic bacterium divides by budding, where a sessile protuberance enlarges at the pole and constricts to separate, unlike symmetric fission. Matches diagram (ii) with polar outgrowth and division.

Bacillus subtilis (R): Undergoes classic binary fission via midcell Z-ring formation during vegetative growth, yielding equal daughters; asymmetric polar septa occur only in sporulation. Matches diagram (i) showing central constriction.

Nocardia species (S): Branched filaments fragment into bacillary or coccoid elements, resembling soft mycelial breakage rather than true fission or budding. Matches diagram (iii) for fragmentation.

Introduction to Bacterial Cell Division Modes Matching

Bacterial cell division modes matching varies by species, with binary fission dominating rods like Bacillus subtilis, while filamentous forms like Streptomyces species use fragmentation. This guide decodes CSIR NET-style questions on Rhodopseudomonas acidophila budding and Nocardia fragmentation for precise exam prep.

Key Modes of Bacterial Reproduction

• Binary Fission: Symmetric midcell split via FtsZ ring, seen in Bacillus subtilis vegetative cells.

• Budding: Polar outgrowth and constriction, characteristic of Rhodopseudomonas acidophila.

• Fragmentation: Hyphal breakage into segments, typical for Nocardia species.

• Septation/Fragmentation: Cross-walls and spore ladders in Streptomyces species hyphae.

Matching Table for Exam Questions

CSIR NET Preparation Tips

Focus on exceptions: Streptomyces skips routine division, using sporulation septa. Rhodopseudomonas acidophila budding distinguishes it from fission. Practice with diagrams for visual matching accuracy.