Viruses, Viroids, Prions & Lichens — NEET Biology MCQs with Solutions
Free NEET Biology Viruses, Viroids, Prions & Lichens MCQs with step-by-step solutions (9 questions). Part of Biological Classification. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Viruses, Viroids, Prions & Lichens · easy · theory
Viruses are NOT included in the five-kingdom classification because they:
A. Are non-cellular and are inert (crystallisable) outside a host ✓ Correct
B. Are prokaryotic cells
C. Are eukaryotic cells
D. Have a true nucleus
Solution: Viruses are non-cellular, obligate intracellular parasites; outside a host they behave as inert crystals — so Whittaker left them out.
Q2 — Viruses, Viroids, Prions & Lichens · easy · theory
The genetic material of the Tobacco Mosaic Virus (TMV) is:
A. Both DNA and RNA
B. Protein
C. RNA ✓ Correct
D. DNA
Solution: Plant viruses usually have single-stranded RNA; animal viruses have ss or ds RNA or DNA.
Q3 — Viruses, Viroids, Prions & Lichens · easy · theory
The protein coat that protects the nucleic acid of a virus is called the:
A. Capsid ✓ Correct
B. Cell wall
C. Envelope of chitin
D. Pellicle
Solution: The capsid is made of subunits called capsomeres and protects the viral genome.
Q4 — Viruses, Viroids, Prions & Lichens · medium · theory
The term "virus" (meaning venom/poisonous fluid) and the discovery that the infectious agent could pass through bacteria-proof filters are credited respectively to:
A. Hooke; Pasteur
B. Stanley; Hooke
C. Beijerinck; Hooke
D. Pasteur; Ivanowsky/Beijerinck ✓ Correct
Solution: Pasteur coined "virus"; Ivanowsky and Beijerinck showed the agent passed bacterial filters (contagium vivum fluidum). Stanley later crystallised TMV.
Q5 — Viruses, Viroids, Prions & Lichens · medium · theory
Viroids differ from viruses in that they:
A. Consist of free RNA only, lacking a protein coat ✓ Correct
B. Are made only of protein
C. Have both DNA and a capsid
D. Are cellular
Solution: Viroids (discovered by Diener) are free, low-molecular-weight RNA without a protein coat — e.g. potato spindle tuber disease.
Q6 — Viruses, Viroids, Prions & Lichens · medium · theory
Lichens are a symbiotic association between:
A. Two fungi
B. Two algae
C. A plant and a bacterium
D. A fungus (mycobiont) and an alga/cyanobacterium (phycobiont) ✓ Correct
Solution: In lichens the algal partner makes food (autotroph) and the fungal partner provides shelter, water and minerals — a mutualism.
Q7 — Viruses, Viroids, Prions & Lichens · hard · theory
Prions are infectious agents responsible for diseases like BSE ("mad cow disease") and CJD. They are composed of:
A. Both DNA and protein
B. Abnormally folded protein (no nucleic acid) ✓ Correct
C. DNA only
D. RNA only
Solution: Prions are misfolded proteins that convert normal proteins to the abnormal form — they contain NO nucleic acid.
Q8 — Viruses, Viroids, Prions & Lichens · hard · theory
Lichens are good pollution indicators (especially of SO₂) because they:
A. Are unaffected by air quality
B. Only grow in cities
C. Do not grow in polluted areas ✓ Correct
D. Absorb all pollutants and thrive
Solution: Lichens are very sensitive to SO₂; their absence signals air pollution, making them reliable bioindicators.
Q9 — Viruses, Viroids, Prions & Lichens · hard · theory
Which statement about viral multiplication is CORRECT?
A. Viruses replicate only inside a living host, using the host machinery, after injecting/entering with their nucleic acid ✓ Correct
B. Viruses grow like bacteria on nutrient agar
C. Viruses possess their own ribosomes
D. Viruses divide by binary fission independently
Solution: Viruses are obligate intracellular parasites: they take over the host's biosynthetic machinery to replicate, having no ribosomes or metabolism of their own.