Understanding the salient features of Monera is essential for B.Pharm students preparing for microbiology and pharmacology exams. This concise, keyword-rich introduction highlights core Monera concepts—prokaryotic cell structure, peptidoglycan cell walls, Gram staining differences, binary fission, plasmids, endospores, metabolic diversity, and antibiotic targets—framed to support MCQ practice and exam readiness. Emphasis on bacterial morphology, physiology, classification, resistance mechanisms, and laboratory identification helps students link theory to pharmaceutical applications such as antimicrobial therapy and drug development. Clear, targeted MCQs with answers will reinforce learning and improve retention. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. Which of the following is a defining feature of organisms in the kingdom Monera?
- Presence of membrane-bound nucleus
- Absence of membrane-bound organelles
- Multicellularity with specialized tissues
- Chloroplast-containing cells like plants
Correct Answer: Absence of membrane-bound organelles
Q2. The genetic material in Monera is typically organized as:
- Linear chromosomes within a nucleus
- Multiple linear chromosomes in mitochondria
- Single circular DNA molecule in the nucleoid
- Chromatin enclosed by nuclear membrane
Correct Answer: Single circular DNA molecule in the nucleoid
Q3. Which ribosome size is characteristic of prokaryotes like Monera?
- 80S
- 70S
- 60S
- 40S
Correct Answer: 70S
Q4. The cell wall of most bacteria in Monera is primarily composed of:
- Cellulose
- Peptidoglycan (murein)
- Chitin
- Sterols and phospholipids
Correct Answer: Peptidoglycan (murein)
Q5. Which staining method differentiates bacteria based on cell wall structure?
- Endospore staining
- Gram staining
- Capsule staining
- Flagella staining
Correct Answer: Gram staining
Q6. Gram-positive bacteria retain crystal violet and appear purple because they have:
- Thin peptidoglycan layer and outer membrane
- Thick peptidoglycan layer without outer membrane
- High lipid content in cell wall
- Multiple membranes like eukaryotes
Correct Answer: Thick peptidoglycan layer without outer membrane
Q7. The outer membrane containing lipopolysaccharide (LPS) is a feature of:
- Gram-positive bacteria
- Fungi
- Gram-negative bacteria
- Viruses
Correct Answer: Gram-negative bacteria
Q8. Which structure helps bacteria adhere to host tissues and surfaces?
- Ribosomes
- Plasmids
- Pili (fimbriae)
- Endospores
Correct Answer: Pili (fimbriae)
Q9. Bacterial endospores are specialized for:
- Motility in aqueous environments
- Reproduction by meiosis
- Survival under extreme conditions
- Protein synthesis acceleration
Correct Answer: Survival under extreme conditions
Q10. Which process is a common mode of asexual reproduction in Monera?
- Binary fission
- Conjugation
- Spore formation by meiosis
- Fragmentation
Correct Answer: Binary fission
Q11. Conjugation in bacteria primarily involves transfer of genetic material via:
- Bacteriophages
- Transformation of free DNA
- Sex pilus and plasmid transfer
- Fusion of nuclei
Correct Answer: Sex pilus and plasmid transfer
Q12. Bacterial transformation refers to:
- Transfer of DNA by bacteriophages
- Uptake of free DNA from the environment
- Direct transfer through a conjugation bridge
- Formation of resistant spores
Correct Answer: Uptake of free DNA from the environment
Q13. Which molecule in Gram-negative bacteria acts as an endotoxin?
- Peptidoglycan
- Teichoic acid
- Lipopolysaccharide (LPS)
- Exotoxin proteins
Correct Answer: Lipopolysaccharide (LPS)
Q14. Antibiotics that inhibit bacterial cell wall synthesis typically target:
- Ribosomal 30S subunit
- DNA gyrase
- Peptidoglycan cross-linking enzymes (transpeptidases)
- Plasma membrane sterols
Correct Answer: Peptidoglycan cross-linking enzymes (transpeptidases)
Q15. Which antibiotic class acts primarily by inhibiting 30S ribosomal subunit and protein synthesis?
- Penicillins
- Tetracyclines
- Cephalosporins
- Beta-lactamase inhibitors
Correct Answer: Tetracyclines
Q16. Bacterial plasmids often carry genes for:
- Human metabolic enzymes
- Antibiotic resistance and virulence factors
- Ribosomal RNA only
- Chloroplast formation
Correct Answer: Antibiotic resistance and virulence factors
Q17. Which term describes bacteria that require oxygen for growth?
- Obligate anaerobes
- Facultative anaerobes
- Obligate aerobes
- Aerotolerant anaerobes
Correct Answer: Obligate aerobes
Q18. Cyanobacteria are unique among Monera because they:
- Lack photosynthetic pigments
- Perform oxygenic photosynthesis and have thylakoid membranes
- Are strictly heterotrophic
- Have membrane-bound chloroplasts
Correct Answer: Perform oxygenic photosynthesis and have thylakoid membranes
Q19. The bacterial growth curve phase where cells adapt but do not multiply rapidly is:
- Log (exponential) phase
- Stationary phase
- Lag phase
- Death phase
Correct Answer: Lag phase
Q20. Which phase of bacterial growth is characterized by balanced rapid cell division?
- Lag phase
- Log (exponential) phase
- Stationary phase
- Death phase
Correct Answer: Log (exponential) phase
Q21. Bacterial spores are most commonly associated with which genera?
- Escherichia and Salmonella
- Staphylococcus and Streptococcus
- Bacillus and Clostridium
- Neisseria and Haemophilus
Correct Answer: Bacillus and Clostridium
Q22. Which of the following is NOT a method of horizontal gene transfer in bacteria?
- Transformation
- Transduction
- Conjugation
- Mitosis
Correct Answer: Mitosis
Q23. Bacteriophages are important in Monera for:
- Acting as organelles for energy production
- Mediating transduction and gene transfer
- Synthesizing peptidoglycan
- Generating spore structures
Correct Answer: Mediating transduction and gene transfer
Q24. Which biochemical test detects bacteria capable of fermenting lactose producing acid and gas?
- Oxidase test
- Indole test
- Methyl red test
- IMViC and lactose fermentation on MacConkey agar
Correct Answer: IMViC and lactose fermentation on MacConkey agar
Q25. Acid-fast staining is primarily used to identify bacteria with cell walls rich in:
- Peptidoglycan alone
- Mycolic acids and high lipid content
- Teichoic acids only
- Chitin and cellulose
Correct Answer: Mycolic acids and high lipid content
Q26. Which gas is produced by nitrogen-fixing bacteria as they convert atmospheric nitrogen?
- Oxygen
- Nitrogen gas (N2) is consumed, ammonia produced
- Carbon dioxide
- Methane
Correct Answer: Nitrogen gas (N2) is consumed, ammonia produced
Q27. Obligate anaerobes are inhibited or killed by:
- High salt concentrations
- Presence of oxygen
- Low pH only
- High temperature exclusively
Correct Answer: Presence of oxygen
Q28. Which structure increases bacterial motility and chemotaxis?
- Capsule
- Flagellum
- Plasmid
- Ribosome
Correct Answer: Flagellum
Q29. Bacterial capsules primarily function to:
- Facilitate DNA replication
- Protect against phagocytosis and desiccation
- Increase protein synthesis
- Generate ATP via oxidative phosphorylation
Correct Answer: Protect against phagocytosis and desiccation
Q30. Which component is a common target of beta-lactam antibiotics?
- Bacterial DNA helicase
- Transpeptidase enzymes involved in cell wall synthesis
- 30S ribosomal subunit
- Bacterial RNA polymerase
Correct Answer: Transpeptidase enzymes involved in cell wall synthesis
Q31. R-plasmids confer bacterial resistance primarily by encoding:
- Ribosomal RNAs
- Antibiotic-degrading enzymes and efflux pumps
- Cell wall synthesis proteins only
- Spore formation factors
Correct Answer: Antibiotic-degrading enzymes and efflux pumps
Q32. Which metabolic type describes bacteria that obtain energy from inorganic compounds and carbon from CO2?
- Photoheterotrophs
- Chemoautotrophs
- Photoautotrophs
- Chemoheterotrophs
Correct Answer: Chemoautotrophs
Q33. The bacterial cell membrane differs from eukaryotic membranes in that it:
- Contains sterols like cholesterol in most species
- Lacks a nucleus and supports electron transport directly at membrane
- Has membrane-bound mitochondria
- Is made of cellulose
Correct Answer: Lacks a nucleus and supports electron transport directly at membrane
Q34. Which test is used to detect cytochrome c oxidase activity in bacteria?
- Coagulase test
- Oxidase test
- Catalase test
- Urease test
Correct Answer: Oxidase test
Q35. Bacterial exotoxins are typically characterized as:
- Heat-stable lipopolysaccharides
- Protein toxins secreted by bacteria with specific targets
- Intracellular metabolic enzymes
- Cell wall structural lipids
Correct Answer: Protein toxins secreted by bacteria with specific targets
Q36. Which method is most appropriate for sterilization of heat-sensitive antibiotics?
- Autoclaving at 121°C
- Boiling for 30 minutes
- Filtration through 0.22 μm membrane
- Dry heat sterilization at 160°C
Correct Answer: Filtration through 0.22 μm membrane
Q37. Biofilms in clinical settings are problematic because they:
- Are easily removed by antibiotics
- Provide increased resistance to antimicrobials and host defenses
- Only form on plant surfaces
- Are exclusively formed by viruses
Correct Answer: Provide increased resistance to antimicrobials and host defenses
Q38. Which component is NOT typical of bacterial membranes?
- Phospholipid bilayer
- Integral membrane proteins
- Chitin polymers
- Hopanoids in some bacteria
Correct Answer: Chitin polymers
Q39. Quorum sensing in bacteria regulates:
- Photosynthesis exclusively
- Population-density dependent gene expression like virulence and biofilm formation
- Only DNA replication timing
- Host cell apoptosis directly
Correct Answer: Population-density dependent gene expression like virulence and biofilm formation
Q40. Which bacterial shape is described as spherical?
- Bacillus
- Coccus
- Spirillum
- Vibrio
Correct Answer: Coccus
Q41. Which staining technique is best to visualize bacterial capsules?
- Simple staining with crystal violet only
- Negative staining with India ink or nigrosin
- Gram staining
- Acid-fast staining
Correct Answer: Negative staining with India ink or nigrosin
Q42. Facultative anaerobes are organisms that:
- Only grow in the absence of oxygen
- Only grow in the presence of oxygen
- Can grow with or without oxygen but prefer oxygen
- Require high CO2 but no oxygen
Correct Answer: Can grow with or without oxygen but prefer oxygen
Q43. The discovery that bacteria have 70S ribosomes helped explain why:
- All antibiotics target eukaryotic ribosomes
- Some antibiotics selectively inhibit bacterial protein synthesis
- Bacteria perform photosynthesis like plants
- Viruses can be treated with antibiotics
Correct Answer: Some antibiotics selectively inhibit bacterial protein synthesis
Q44. Which of the following best describes facultative intracellular pathogens?
- Cannot enter host cells
- Only survive outside host cells
- Can live both inside and outside host cells
- Are obligate viruses
Correct Answer: Can live both inside and outside host cells
Q45. Which bacteria are primary producers in many aquatic ecosystems due to oxygenic photosynthesis?
- Cyanobacteria
- Firmicutes
- Actinobacteria
- Chlamydia
Correct Answer: Cyanobacteria
Q46. The IMViC test series is especially useful for distinguishing:
- Gram-positive cocci
- Enteric Gram-negative rods like E. coli and Enterobacter
- Anaerobic spore-formers
- Acid-fast bacilli
Correct Answer: Enteric Gram-negative rods like E. coli and Enterobacter
Q47. Which mechanism does NOT contribute to antibiotic resistance?
- Target modification
- Enzymatic drug inactivation
- Increased drug uptake by porins
- Efflux pumps removing antibiotic
Correct Answer: Increased drug uptake by porins
Q48. Bacterial endotoxin-induced septic shock is mainly due to excessive release of:
- Exotoxin proteins
- Lipopolysaccharide (LPS) leading to cytokine storm
- Viral particles
- Antibody-antigen complexes
Correct Answer: Lipopolysaccharide (LPS) leading to cytokine storm
Q49. In industrial microbiology, Monera members are exploited for:
- Production of antibiotics, enzymes, amino acids, and fermented products
- Serving as eukaryotic model organisms for organelle studies
- Generating complex multicellular tissues
- Replacing mammalian cells in organ transplants
Correct Answer: Production of antibiotics, enzymes, amino acids, and fermented products
Q50. Which taxonomic revision reflects current understanding of prokaryotic diversity beyond the traditional kingdom Monera?
- Retention of Monera as a single kingdom for all microbes
- Division into Bacteria and Archaea domains based on molecular phylogeny
- Grouping prokaryotes with plants
- Classifying all prokaryotes as fungi
Correct Answer: Division into Bacteria and Archaea domains based on molecular phylogeny
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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