Cistron is the gene which has the information to code for a polypeptide chain. The structural genes in prokaryotes are located one after the other and forms polycistronic mRNA. The structural genes in eukaryotes form mostly monocistronic mRNA.
The mRNA which contains information to code for more than one polypeptide chain is said to be polycistronic. Polycistronic mRNA is mostly found in prokaryotes.
The mRNA which contains information to code for only one polypeptide chain is said to be monocistronic. Monocistronic mRNA is mostly found in the eukaryotes.
Therefore, statements II, III, IV are correct and statements I, V are incorrect.