Kingdom Monera — NEET Biology MCQs with Solutions
Free NEET Biology Kingdom Monera MCQs with step-by-step solutions (71 questions). Part of Biological Classification. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Kingdom Monera · easy · theory
Bacteria are grouped under Kingdom Monera because they are:
A. Prokaryotic ✓ Correct
B. Multicellular
C. Eukaryotic
D. Photosynthetic only
Solution: Monera comprises prokaryotes — organisms lacking a true membrane-bound nucleus and organelles.
Q2 — Kingdom Monera · easy · theory
On the basis of shape, a comma-shaped bacterium is called a:
A. Coccus
B. Bacillus
C. Vibrium (vibrio) ✓ Correct
D. Spirillum
Solution: Shapes: coccus (spherical), bacillus (rod), vibrium (comma), spirillum (spiral).
Q3 — Kingdom Monera · easy · theory
Archaebacteria differ from other bacteria mainly in the structure of their:
A. Cell membrane (branched-chain lipids) ✓ Correct
B. Nucleus
C. Ribosomes only
D. Mitochondria
Solution: Archaebacteria have a distinctive cell-wall structure and branched-chain lipids in the membrane, allowing survival in extreme habitats.
Q4 — Kingdom Monera · medium · theory
Methanogens, which produce methane (biogas) in the guts of ruminants, are:
A. Cyanobacteria
B. Mycoplasma
C. Archaebacteria ✓ Correct
D. Eubacteria (heterotrophic)
Solution: Methanogens are archaebacteria found in marshy areas and ruminant guts; they generate methane from CO₂/H₂.
Q5 — Kingdom Monera · medium · theory
Cyanobacteria (blue-green algae) fix atmospheric nitrogen in specialised cells called:
A. Basal cells
B. Hormogonia
C. Akinetes
D. Heterocysts ✓ Correct
Solution: Heterocysts are thick-walled, anaerobic cells (e.g. in Nostoc, Anabaena) that carry out nitrogen fixation.
Q6 — Kingdom Monera · medium · theory
Which group of Monera lacks a cell wall entirely and can survive without oxygen?
A. Actinomycetes
B. Chemosynthetic autotrophs
C. Cyanobacteria
D. Mycoplasma ✓ Correct
Solution: Mycoplasma are the smallest living cells, completely lack a cell wall, and many are anaerobic; some are pathogenic.
Q7 — Kingdom Monera · hard · theory
Chemosynthetic autotrophic bacteria obtain energy by oxidising inorganic substances such as nitrates, nitrites and ammonia. Their ecological importance is that they:
A. Perform oxygenic photosynthesis
B. Recycle nutrients (e.g. nitrogen, sulphur, iron) ✓ Correct
C. Fix carbon using sunlight
D. Cause food spoilage only
Solution: They derive energy from inorganic oxidation and play key roles in the recycling of N, S, P, Fe etc.
Q8 — Kingdom Monera · hard · theory
The mode of nutrition in the majority of Eubacteria is:
A. Photoautotrophic
B. Always parasitic
C. Heterotrophic (mostly decomposers) ✓ Correct
D. Chemoautotrophic
Solution: Most eubacteria are heterotrophs — important decomposers; some are autotrophic (photo- or chemosynthetic).
Q9 — Kingdom Monera · hard · theory
Which feature is shared by BOTH archaebacteria and eubacteria?
A. 80S ribosomes
B. Histone-wrapped chromosomes identical to eukaryotes
C. 70S ribosomes and a single circular DNA ✓ Correct
D. Membrane-bound nucleus
Solution: Both are prokaryotes with 70S ribosomes and a naked circular chromosome; archaea differ in wall/membrane chemistry and some molecular features.
Q10 — Kingdom Monera · easy · numerical
Colonies of cyanobacteria (blue-green algae) are commonly surrounded and held together by a:
A. layer of cellulose fibres
B. rigid chitinous wall
C. thick waxy cuticle
D. gelatinous mucilaginous sheath ✓ Correct
Solution: Cyanobacterial filaments/colonies are enclosed in a gelatinous (mucilaginous) sheath, not chitin, cuticle or cellulose.
Q11 — Kingdom Monera · easy · numerical
Which of the following is a free-living, nitrogen-fixing cyanobacterium?
A. Rhizobium
B. Nostoc ✓ Correct
C. Lactobacillus
D. Chlamydomonas
Solution: Nostoc is a free-living nitrogen-fixing cyanobacterium; Rhizobium is a symbiotic bacterium, Chlamydomonas is a green alga, and Lactobacillus does not fix nitrogen.
Q12 — Kingdom Monera · easy · numerical
Bacteria that meet their nutritional needs by breaking down dead and decaying organic matter are described as:
A. photosynthetic autotrophs
B. saprophytic heterotrophs ✓ Correct
C. chemosynthetic autotrophs
D. symbiotic nitrogen fixers
Solution: Decomposer bacteria that feed on dead organic matter are saprophytic (heterotrophic); autotrophs make their own food and symbionts live with a host.
Q13 — Kingdom Monera · medium · numerical
Archaebacteria living in extremely salty areas, in hot acidic springs, and in marshy or ruminant-gut environments are respectively called:
A. halophiles, thermoacidophiles and methanogens ✓ Correct
B. halophiles, methanogens and thermoacidophiles
C. methanogens, halophiles and thermoacidophiles
D. thermoacidophiles, methanogens and halophiles
Solution: Salt-lovers are halophiles, hot-acid dwellers are thermoacidophiles, and methane-producers of marshes/guts are methanogens.
Q14 — Kingdom Monera · medium · numerical
The remarkable ability of archaebacteria to survive extreme habitats is largely attributed to the unusual chemistry of their:
A. cytoplasm, which is packed with cellulose granules
B. cell wall, which is rich in peptidoglycan and muramic acid
C. cell membrane, which contains branched-chain, ether-linked lipids ✓ Correct
D. nucleus, which is bounded by a double membrane
Solution: Archaebacterial membranes have distinctive branched-chain, ether-linked lipids that resist extreme conditions; their walls notably LACK peptidoglycan and they have no true nucleus.
Q15 — Kingdom Monera · medium · numerical
Assertion (A): Many cyanobacteria can fix atmospheric nitrogen even while carrying out oxygen-releasing photosynthesis. Reason (R): Nitrogen fixation is confined to heterocysts, which provide an oxygen-free microenvironment for the enzyme nitrogenase.
A. A is false but R is true
B. Both A and R are true but R is not the correct explanation of A
C. Both A and R are true and R is the correct explanation of A ✓ Correct
D. A is true but R is false
Solution: The oxygen-sensitive nitrogenase works because heterocysts create an anaerobic microenvironment, letting fixation continue alongside photosynthesis — R correctly explains A.
Q16 — Kingdom Monera · medium · numerical
Match the moneran with its mode of nutrition: (i) Cyanobacteria (ii) Nitrifying chemosynthetic bacteria (iii) Majority of eubacteria; (p) photoautotroph (q) chemoautotroph (r) heterotroph.
A. (i)-(r), (ii)-(q), (iii)-(p)
B. (i)-(q), (ii)-(p), (iii)-(r)
C. (i)-(p), (ii)-(r), (iii)-(q)
D. (i)-(p), (ii)-(q), (iii)-(r) ✓ Correct
Solution: Cyanobacteria are photoautotrophs, nitrifying bacteria oxidise inorganic substances as chemoautotrophs, and most eubacteria are heterotrophs.
Q17 — Kingdom Monera · easy · theory
What is the mode of nutrition in Monera?
A. All of these ✓ Correct
B. Heterotrophic
C. Photosynthetic
D. Chemosynthetic
Solution: Monerans show heterotrophic, chemosynthetic and photosynthetic nutrition.
Q18 — Kingdom Monera · easy · theory
What is the mode of nutrition in blue-green monerans (cyanobacteria)?
A. None of these
B. Heterotrophic
C. Both autotrophic and heterotrophic
D. Autotrophic ✓ Correct
Solution: Cyanobacteria are photosynthetic autotrophs.
Q19 — Kingdom Monera · easy · theory
Mode of nutrition in bacteria is:
A. Parasitic
B. All of the above ✓ Correct
C. Chemosynthetic and photosynthetic
D. Saprophytic
Solution: Bacteria show autotrophic (photo/chemosynthetic) and heterotrophic (saprophytic/parasitic) nutrition.
Q20 — Kingdom Monera · medium · theory
Moneran cell wall is composed of:
A. Polysaccharide (cellulose)
B. Polysaccharide (chitin)
C. Amino acid and non-cellulosic polysaccharide ✓ Correct
D. Polysaccharide (non-cellulose) only
Solution: Bacterial cell wall is peptidoglycan (amino acids + polysaccharide).
Q21 — Kingdom Monera · easy · theory
Chemosynthetic mode of nutrition is found in:
A. Protista
B. Monera ✓ Correct
C. Fungi
D. Plantae
Solution: Chemosynthetic autotrophs are bacteria belonging to Monera.
Q22 — Kingdom Monera · medium · theory
Which statement is correct? (i) Cyanobacteria form blooms in polluted water bodies; (ii) Chemosynthetic autotrophic bacteria oxidise inorganic substances and use the released energy for ATP production; (iii) Heterotrophic bacteria are the most abundant in nature and majority are important decomposers.
A. Only chemosynthetic autotrophs oxidise inorganic substances for ATP
B. All are correct ✓ Correct
C. Only cyanobacteria form blooms in polluted water bodies
D. Only heterotrophic bacteria are the most abundant decomposers
Solution: All three statements about cyanobacteria, chemosynthetic and heterotrophic bacteria are true.
Q23 — Kingdom Monera · medium · theory
Archaebacteria survive in extreme conditions due to:
A. Different cell wall structure
B. Oxidising various inorganic substances
C. Different cell membrane structure
D. More than one is correct (different cell wall and cell membrane structure) ✓ Correct
Solution: Their distinctive cell wall and membrane lipids let them survive extreme habitats.
Q24 — Kingdom Monera · medium · theory
Cyanobacteria:
A. Are heterotrophic
B. More than one is correct ✓ Correct
C. Are unicellular, colonial or filamentous, aquatic or terrestrial algae
D. Have chlorophyll a similar to green plants
Solution: Cyanobacteria have chlorophyll a and are unicellular, colonial or filamentous; they are autotrophic (not heterotrophic).
Q25 — Kingdom Monera · easy · theory
Bacteria reproduce mainly by:
A. Fission ✓ Correct
B. Recombination
C. Spores
D. Conjugation
Solution: Bacteria reproduce mainly asexually by binary fission.
Q26 — Kingdom Monera · medium · theory
Which statement is correct for mycoplasma?
A. They are the smallest living cells known ✓ Correct
B. They completely have a cell wall
C. They cannot survive without oxygen
D. All are correct
Solution: Mycoplasmas lack a cell wall, can survive without oxygen and are the smallest living cells.
Q27 — Kingdom Monera · easy · theory
Based on their shape, bacteria are grouped as:
A. Coccus, Bacillus, Vibrio and Rickettsia
B. All of the above
C. Coccus, Bacillus, Mycoplasma and Spirillum
D. Coccus, Bacillus, Vibrio and Spirillum ✓ Correct
Solution: The four shapes are coccus, bacillus, vibrio and spirillum.
Q28 — Kingdom Monera · easy · theory
Based on their shape, bacteria are:
A. Spherical, rod-shaped, comma-shaped and filamentous
B. Spherical, rod-shaped, oval and Spirillum
C. None of the above
D. Spherical, rod-shaped, comma-shaped and spiral ✓ Correct
Solution: Coccus (spherical), bacillus (rod), vibrio (comma) and spirillum (spiral).
Q29 — Kingdom Monera · easy · theory
Archaebacteria live in:
A. Only salty areas
B. Only hot springs
C. All of these (salty areas, marshy areas, hot springs) ✓ Correct
D. Only marshy areas
Solution: Archaebacteria (halophiles, methanogens, thermoacidophiles) live in all these extreme habitats.
Q30 — Kingdom Monera · medium · theory
Which is not correct for methanogens?
A. They are responsible for the production of methane
B. They are present in the gut of several ruminant animals such as cows and buffaloes
C. They are responsible for the production of biogas from the dung of ruminants
D. They are responsible for the production of methanol ✓ Correct
Solution: Methanogens produce methane (biogas), not methanol.