Q.29 Match the cell structures in Group I with the organismsin Group II.
Group I Group II
P. Endospores 1. Methanobacterium
Q. Bipolar flagella 2. Treponema
R. Pseudomurine in cell wall 3. Spirillum
S. Periplasmic flagella 4. Clostridium
(A) P-4, Q-3, R-1, S-2 (B) P-4, Q-3, R-2, S-1
(C) P-3, Q-4, R-1, S-2 (D) P-4, Q-1, R-3, S-2
Correct Answer: (A) P-4, Q-3, R-1, S-2. Endospores form in Clostridium, bipolar flagella characterize Spirillum, pseudomurein defines Methanobacterium cell walls, and periplasmic flagella enable Treponema motility.
Cell Structure Functions
These prokaryotic features provide survival, locomotion, and structural integrity. Endospores resist harsh conditions, flagella configurations determine movement patterns, pseudomurein replaces peptidoglycan in archaea, and periplasmic flagella power spirochete rotation.
Correct Matching Details
P. Endospores → 4. Clostridium. Gram-positive anaerobes like Clostridium form heat/chemical-resistant endospores via sporulation, containing dipicolinic acid for desiccation tolerance.
Q. Bipolar flagella → 3. Spirillum. These rigid spirals exhibit lophotrichous flagella at both poles, enabling rapid darting motility in aquatic environments.
R. Pseudomurein in cell wall → 1. Methanobacterium. Methanogenic archaea use pseudomurein (N-acetyltalosaminuronic acid-β-1,3-linked) instead of bacterial peptidoglycan, resisting lysozyme due to distinct glycosidic bonds.
S. Periplasmic flagella → 2. Treponema. Spirochetes house axial filaments (periplasmic flagella) between outer sheath and protoplasmic cylinder, creating corkscrew propulsion.
Option Analysis
Option (B) P-4, Q-3, R-2, S-1 incorrectly swaps pseudomurein to Treponema (bacterial peptidoglycan) and periplasmic flagella to Methanobacterium (non-motile archaeon).
Option (C) P-3, Q-4, R-1, S-2 wrongly assigns endospores to Spirillum (non-sporeformer) and bipolar flagella to Clostridium (peritrichous).
Option (D) P-4, Q-1, R-3, S-2 mismatches bipolar flagella to Methanobacterium (archaeal, lacks true flagella) and pseudomurein to Spirillum (peptidoglycan).
Microbial Taxonomy Insights
This matching distinguishes bacterial (Clostridium, Spirillum, Treponema) from archaeal (Methanobacterium) cell walls—pseudomurein biosynthesis uses talosaminuronic acid and β-1,3 linkages, enabling methanogen survival in anaerobic niches.
