The correct answer is Option B) prions
Prions are named by Stanley Prusiner (got Nobel Prize in 1997). Prions are infectious agents which are made of proteins only (without nucleic acid). Prions are the causal agents of scrapie disease of sheep.
The correct answer is Option B) prions

Given below are two statements:
Statement I: Transfer RNAs and ribosomal RNA do not interact with mRNA.
Statement II: RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.
In the light of the above statements, choose the most appropriate answer from the options given below:
The process of grouping living organisms into categories is called biological classification. The most modern 5-kingdom classification was put ahead by an eminent scientist R.H.Whittaker. The five-kingdom classification is based on the criteria like cell structure, mode of nutrition, body form, and reproduction. One of the most important characteristics of this system is that it follows the evolutionary sequence of living organisms. The organisms are classified into distinct taxa or levels like Kingdom, Phylum, Division, Class, Order, Family, Genus, and Species. The 5 kingdoms are as follows:
