Answer: Viroids lack the protein coat present in viruses and have smaller RNA.
- A Viroids possess a capsid protein coat that surrounding viruses largely lack
- B Viroids lack the protein coat present in viruses and have smaller RNA
- C Viroids carry mainly double-stranded DNA genomes while viruses generally carry RNA
- D Viroid particles are consistently larger in physical size than virus particles
Correct answer: B. Viroids lack the protein coat present in viruses and have smaller RNA
Explanation: Viroids consist of free RNA with no protein coat, and the RNA is of much lower molecular weight than that of viruses. Viruses, in contrast, have their nucleic acid enclosed in a protein capsid.
Whittaker's five-kingdom system (1969) groups all cellular life by cell structure and nutrition; viruses, viroids, and lichens fall outside this system entirely since they aren't independently classifiable as one of the five.
Concept context
Whittaker's five kingdom system covering Monera, Protista, Fungi, plus viruses, viroids, and lichens. A foundational NEET chapter on how living organisms are grouped.