UPSC Prelims 2002·GS1·science-and-technology·science and technology

Which one of the following statements is correct?

Dalvoy logo
Reviewed by Dalvoy
UPSC Civil Services preparation
Last updated 23 May 2026, 3:31 pm IST
  1. APrions are the smallest free-living cells
  2. BThe cell wall of Mycoplasmas is made up of amino sugars
  3. CViroids consist of a single stranded RNA moleculeCorrect
  4. DRickettsia’s lack cell wall

Explanation

Option C is correct because viroids are infectious agents that are even smaller than viruses and consist solely of a short, circular, single stranded RNA molecule without a protein coat. The other options are incorrect for the following reasons: Prions are not cells but are infectious misfolded proteins that do not contain genetic material. Mycoplasmas are unique because they completely lack a cell wall, making them resistant to many antibiotics. Rickettsias are a group of bacteria that do possess a true cell wall, similar to other gram negative bacteria.
science-and-technology: Which one of the following statements is correct?
ShareWhatsAppXTelegram

Related questions

More UPSC Prelims practice from the same subject and topic.