Which of the following statements is INCORRECT regarding viroids?
They are smaller than viruses.
They are infectious RNA molecules.
They lack a protein coat.
They contain a protein coat.
Related Questions
Tobacco mosaic virus is a tubular filament of size
300 × 20 nm
700 × 30 nm
300 × 10 nm
300 × 5 nm
Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom viruses belong to?
Monera
Protista
Fungi
None of these
I. DJ Ivanowsky (1892) recognised certain microbes as causal organisms of the mosaic disease of tobacco
II. MW Beijerinck (1898) demonstrated that the extract of infected plants of tobacco could cause infection in healthy plants and called the fluid as contagium vivum fluidum
III. WM Stanley (1935) showed that these microbes could be crystallised and crystals consist largely of protein
The above statements are assigned to
Bacteria
Virus
Prions
Lichens
RNA is not found in one of the following organisms
TMV
HIV
Viroids
Prions
Which of the following statement is false?
TMV has a double-stranded RNA molecule
Most plant viruses are RNA viruses
The bacteriophage has a double-stranded DNA molecule
Most animal viruses are DNA viruses
Which of the following statement is correct?
Viruses are obligate parasites
All fungi are pathogenic
All algae are eukaryotes
Bacteria are always harmful to mankind
Which of the following are correct to describe viruses?
I. Simple and unicellular organism.
II. Contain DNA or RNA and enclosed by protein coat.
III. Possess own metabolic system and respond to stimuli.
IV. Maintain genetic continuity and undergo mutations.
The correct combination is
I and II
II and IV
II and III
I and III
A scientist discovers a new infectious agent that causes disease in plants. It is smaller than a virus and composed solely of RNA without a protein coat. What is the most likely classification of this agent?
Virus
Prion
Viroid
Lichen
Enveloped virus enters into host cells by
Injecting own nucleic acid inside host cells
By contact with cell receptor and endocytosis
By phagocytosis
Fusion with the plasma membrane of host
Which one of the following does not grow in artificial media?
TMV
Bacteria
Yeast
Rhizopus
